The BSA A7-A10 Forum
Technical (Descriptive Topic Titles - Stay on Topic) => Gearbox, Clutch, Primary => Topic started by: RoyC on 19.06. 2018 21:20
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I have an SRM 4 spring clutch. (Primary has Castrol 20.50).
When the bike has stood for a day and I come to start it up, pull the clutch lever in and go to kick start.
The clutch does not disengage, (like the plates are stuck together,) until I bump on the kick start a couple of times, then it frees up and works as normal.
It does this every time it has stood for a while.
Any ideas anyone ?
Roy
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I have an srm pressure plate on one bike and a similar but other version on the Flash - both do this if the bike has stood a bit, think it is a common thing, I automatically pull in clutch and give a sharp kick which fres it
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I have an srm pressure plate on one bike and a similar but other version on the Flash - both do this if the bike has stood a bit, think it is a common thing, I automatically pull in clutch and give a sharp kick which fres it
I have to do exactly the same.
As long as it's nothing that I have done wrong setting it up. *smile*
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G'day Roy.
Both mine do that. The plunger might take two or three kicks to free and the cafe with a sNorton diaphragm clutch takes two.
Cheers
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this is kinda what I was getting at in the other thread of 'ATF' (?), but couldn't be arsed saying...ATF will maybe theoretically be more forgiving as far as 'stiction' goes than what heavier oil is... *dunno*..having said that, the Plunger chainwheel has a flange for the cover to bolt on to, that may inhibit oil flowing to the plates
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Hi Roy,
I can't say if mine sticks (maybe it does). Currently using 8 fl oz of Morris Golden Film 20/50 in chaincase. My starting routine is to tickle the carb, ease the kickstart by pulling in the clutch lever a bit to move it down about half way and not on tdc and then give it a couple of gentle press downs (not kicks) with my foot just to prime - bring it to tdc and then with usually one firm kick away she goes.
Having said that I haven't got my pressure plate screwed in too far. At least one spring coil showing when engaged as SRM instuctions. I have seen photos of them screwed in so far that the spring coils have disappeared inside the cups.
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Having said that I haven't got my pressure plate screwed in too far. At least one spring coil showing when engaged as SRM instuctions.
Hi Roger, I have my springs adjusted the same as yours.
I can go to my bike after it has stood for a day or two and, with the clutch pulled in I can kick it over a couple of times before the clutch will disengage.
It didn't do that with the six spring clutch. *dunno*
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When my bike is in neutral and ticking over while on the centre stand the back wheel will turn slowly but stops easy enough if I put my toe against the side of the tyre so just enough friction there to turn it. As far as I can remember every bike I've had has done that. I wouldn't worry about it if you've no drag and can change gear and find neutral easy.
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i have not been to the pub, I use a six spring and allways give it a couple of free kicks before starting to free it off , if I leave it a long time I can feel it freeing I had a szki 750 and left for 3months it was a bstd to free off , some clutches if left for 6 months or more have to be drastickly freed off or taken apart, like leaving a handbrake on a car for 3 months and having to go back and forth to free it { allways leave in gear for long periods with handbrake off unless your on a mountain *eek*} as for the oil bit am I missing something because there should be no oil on the plates unless the clutch is designed to run in oil. back again , as for wheel rotation this means you have pretty good sleeve gear bushes
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I have a 6 spring and I am in the office at work.
I never even have to bother to clear the clutch, even after a six month lay up. I am running ATF of unknown brand/type in there.
In that respect it is better than other of my bikes, most notably the XLH1200 and ZRX1200R which I have to clear by putting in gear and rocking backwards and forwards before then firing up. And even then that first shift into, err first, is with a hell of a bang.
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now theres a thing , but do you get clutch slip with it when giving it race track treatment over 5500 rpm, I used to but have now set it up with no clunks into first or second and easily disengageing at standstill, ime still amazed it doesn't slip at super thrash mode..... time will tell *shh*
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as for the oil bit am I missing something because there should be no oil on the plates unless the clutch is designed to run in oil.
Primary chain dips in 8 fl oz of oil in bottom of chaincase and then it gets thrown around and it gets on the clutch plates.
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I have a 6 spring and I am in the office at work.
I never even have to bother to clear the clutch, even after a six month lay up. I am running ATF of unknown brand/type in there.
I used ATF with my old 6-spring but SRM (whose 4-spring a lot of us have now) explicity advises against using ATF because of its anti-friction properties that can cause clutch slip. I always had difficulty selecting neutral with my 6-spring, changing gears was ok. Since fitting the 4-spring I've had no problems selecting neutral, no slip, no drag, very easy to set up as the non flexing pressure plate self-centralises and lifts squarly with the needle roller pusher.
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At least with a pommy bike you can free the clutch with the kickstart. My XT500 takes off when put into gear and takes 1/4 mile of riding with the clutch lever pulled in before it breaks free *eek*
Cheers
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At least with a pommy bike you can free the clutch with the kickstart. My XT500 takes off when put into gear and takes 1/4 mile of riding with the clutch lever pulled in before it breaks free *eek*
Cheers
Can't you put the brakes on and use the starter to free it ?
Oh well, at lease I have learned that there is nothing wrong with my SRM. *smiley4*
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Oh well, at lease I have learned that there is nothing wrong with my SRM. *smiley4*
*smile*
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Yes, my XLH dragged me out into the road outside my house one time I kicked it into gear. Added a certain frisson to the commute that morning.
My A10 never goes above 3k rpm so I guess I'm not likely to see other issues.
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This is an interesting discussion. I have 7 bikes (see profile) and not a one sticks the clutch no matter how long they sit. I guess I'm very lucky. I do use the OEM recommended oils in all chain/trans cases though................
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On Hardley it got to the point where the plates wouldn't free at all. I stripped them all out and cleaned them but they quickly reverted. They must have got contaminated with something ... ? I ended up replacing the pack with new. There is a sprung plain plate in there to keep a very gentle drag - designed in to make sure the dogs are against their 'oles for the big bang on first engagement.
I think all japanese bikes are a bit crunchy going into first. Worse than the more widely maligned Guzzis by my book.
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I know that my plates are not contaminated, it's a new SRM clutch.
I am also using the recommended lubricant.
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[quote......I have a 6 spring and I am in the office at work.
......[/quote]
Must be before liquid smoko... *beer*...
To be honest, I'm not sure if I need to free- up or not... maybe sometimes *dunno2* usually I just roll it around until I find TDC-ish, and kick....I think Plungers may be a different animal... don't have the issue with the Gutzzi either
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This is an interesting discussion. I have 7 bikes (see profile) and not a one sticks the clutch no matter how long they sit. I guess I'm very lucky. I do use the OEM recommended oils in all chain/trans cases though................
My Goldwing clunks VRY badly when cold, and just badly when hot *eek* doesn’t seem to do much harm tho.
B31 with modified (extra thick metal plates) 6 spring crunches very badly all the time.....I suspect that’s the gearbox design at fault, not the clutch, as neutral is found very easily.
My A10 with bog std 6 spring crunches only slightly cold or hot, neutral is very easy to find, but I ALWAYS through habit free the clutch, whilst at the same time making sure the kickstart gears won’t jam. There’s nothing more annoying than taking a swing and the kickstart lever not moving cos it’s jammed *problem*
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There’s nothing more annoying than taking a swing and the kickstart lever not moving cos it’s jammed *problem*
My kickstart used to jam, so I replaced the Quadrant and the pinion, been ok ever since. *smile*
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I'm going to have a swing at this one, (PUN intended).
These clutches are in oil, and when the bike goes from very hot, aerated oil (yep millions of air bubbles in that chain case) to just cold oil, it goes from very liquid, to thick tacky oil. And then after sitting for a while, constant clutch spring pressure, sometimes days, sometimes weeks, sometimes months, squeezes all air out and brings the oil film to a minute thickness, so if there is any air, and there will be, it creates a vacuum (suction) this will be from trapped hot air bubbles becoming cool. This is the sticking!
This is not bad trust me.. There is no need to roll the engine over on the clutch from cold (unless you have a'1'Oclock kicker maybe !) all you do is release the suction and allow a bit of lubrication, which at this point, on a cold start up, is NOT what you want. For the people that do this as a start up regime (kick the engine over on the clutch, COLD), you may not notice, as its hard to feel, "clutch slip'', as there still is resistance but not enough to spin the motor enough to fire.
This is from experience.
To free the clutch, once it's running, then pull the clutch for a while, or if its on a center stand let the rear wheel spin in neutral and then hit the rear brake.
Or just ride it.
I have couple Hi Comp bikes with 4 springers, I only really have this minor issue on them, and wouldnt call it a problem.
Just a note, I don't know why you have to kick over a bsa on the clutch from cold ?
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That's a very interesting take on it Beeza.
Just to clarify, in case my starting routine was misunderstood by anybody (reply 5): For cold starting I don't spin the clutch with the clutch lever pulled in. I only use the lever to disengage the clutch to be able to move the kickstart down to an easier position for me to prime the engine. When it's in an acceptable position for me I release the lever (so clutch engaged) and depress the kickstart a couple of times to turn the engine over to prime it. Then I give it a firm kick, well for me, these days, it's more of a little jump up and a firm stamp down on the kickstart (not got the strength that I once had *sad2*).
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My 4 springer is, I'm sure on it's last legs as to start I have to free it and then to get it to spin the engine slacken the clutch cable ,start ,let her idle for a few mins and then tighten the cable to be able to get neutral ,sounds a lot but takes a couple of mins and then she's fine, until the next time she's parked up, sulking I guess ?
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i have not been to the pub, beeza says these clutches are in oil,{they don't like oil or ATF} am I on my own in thinking if as a person you had loads of pressure pushing you onto a surface for 40 hours you wouldn't tend to stick to that surface a little. when I changed my box{ sounds interesting} a couple of weeks ago not one plate had oil on it, there was slight grease throw from the bearing. the clutch set up correctly is working so well in conjunction with a good box that there are NO CLUNKS at all. infact putting my foot onto the gear shift{JUST FOR THE YANKS}into first or second from standstill is best described as as using a feather duster. no sound no drag ,{ YES AND I AM AMAZED} infact when first putting her in first after finishing the job I thought something was wrong. don't ask how I've managed this because even I don't know apart from carefully selecting shafts gears selector forks, well the hole lot from 3 stood about for decades boxes plus taking my time with the six spring clutch, final note the other box CLUNKED using the same clutch set up maybe I've built a lovely box *beer*
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I got on to Gary at SRM, this is his reply.
Gary Hearl (gary@srmclassicbikes.com)
Hello Roy,
As you can see from the forum a normal occurrence on a lot of clutches from different makes and models.
This is usually down to oil grade type used.
Firstly i`ll go through the ATF.TQF issues.
This oil is designed for automatic gearboxes, the oil contains additives that makes things slippery, in a bikes clutch this will end up a disaster. Symptom will be clutch will slip at high rpm when the power kicks in from the camshaft, so you tighten the springs a little, issue goes away, but after a while it returns, so you tighten springs again a little, issue goes away, but then returns after a while, this will go on, until you cannot pull your clutch in as the springs are tightened too much; once friction plates have been soaked in ATF.TQF they are contaminated and will have to be replaced.
Looking at your photo, seems springs are a tad adjusted up too tightly, try slacking off a little, so you can see at least 1 -1/2 coils of spring above the top of the spring cup, as usually these clutches can be adjusted lightly and give a two finger lift operation. If too tight, they may cause the plates to stick together from the pressure at rest. And be hard to lift in operation.
20/50 is bordering on being too thick an oil to use, but at least being a normal oil the friction plates can be cleaned off, if possible try and locate some SAE20 straight monograde oil , have heard customers with our clutches using this oil and never having a sticking issue.
Anyway, try slacking off the springs a little first and try the clutch, if it doesn’t stick from rest after a couple of days, and doesn’t slip at high rpm , then all is good, if not, try the SAE 20 mineral grade oil, remember the oil is only there to lubricate the drive chain and clutch centre rollers, hence the small amount recommended by the factory. And it Is normal for friction plates to get wet from oil splash, and nothing to be concerned about.
Let me know how you get on.
Regards Gary
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Mmm.. I'll be interested to hear what our resident wizards make of that criticism of ATF in primaries
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I got on to Gary at SRM, this is his reply.
Well done Roy *clap* .
I, for one, am thankful to Gary for taking the trouble to explain SRM's take on it. It'll always be one of those contentious topics (like Brexit) *smile*.
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I totally agree with RogerSB re:Gary taking the trouble to post good info. I for one wouldn't hesitate using
SRM as and when a clutch job is needed. I guess it's a case of you get what you pay for including free advice. 👍😀
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Hi All,
The oil I use in the primary is intended for wet clutch motorcycle engines (Castrol 10/40, Atevo ??)
No problems with the plates sticking, 4 spring clutch with Surflex plates
John
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Hi All,
The oil I use in the primary is intended for wet clutch motorcycle engines (Castrol 10/40, Atevo ??)
No problems with the plates sticking, 4 spring clutch with Surflex plates
John
Exactly the same here. Two finger operation, no slipping, no dragging, no sticking.
It boggles my mind at times as to why people who work on bikes for a living, are questioned by people who do it as a hobby?
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As Gary Hearl points out, ATF is designed specifically for automatic transmissions; the oil has properties to cope with the application.
You might find this point interesting
One of those properties is to absorb (entrain) air bubbles. This leads to sponginess (compressibility) in the oil.
I have worked in the fluid power (hydraulics) industry all my life (and still at it). Occasionally we will receive a high pressure (10,000 psi) hand pump & ram assembly (with ATF in the pump reservoir) in for repair because it won't reach full pressure (will only get to 7,000 psi), and / or won't hold under load (it sags down).
The solution is to replace the ATF with mineral oil (10 - 32 cSt); the pump will then reach 10,000 psi, and the ram will not creep down. this takes all of 5 minutes.
The reason is the presence of air bubbles in the ATF, which is doing what it is designed to (capture the air).
As far as using ATF in primary drive cases, i don't. the recommended mineral oil does the job best. It is a higher viscosity (thicker).
Richard
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I've ordered this.
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It'll always be one of those contentious topics (like Brexit) *smile*.
*yeah*
Did some experimenting with different oils in the past, and indeed found that a heavier oil made a stickier clutch.
In the end settled for a 10 monograde oil which works perfectly well in combination with the SRM pressure plate
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could you have a loop to slip over handlebar end to hold lever in when stood ??
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could you have a loop to slip over handlebar end to hold lever in when stood ??
Cable tie for instance.
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could you have a loop to slip over handlebar end to hold lever in when stood ??
I had already given that a thought.
I use one of these to hold my front brake on when parked. (it's a combo)
I'll try adjusting the springs and changing oil first though.
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could you have a loop to slip over handlebar end to hold lever in when stood ??
130g bean can (eat the beans first) / length of 50mm pipe/ hose clamp
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could you have a loop to slip over handlebar end to hold lever in when stood ??
130g bean can (eat the beans first) / length of 50mm pipe/ hose clamp
Wife's fingers *doubt* , or as Roy suggested at one time your dog's teeth (if you have one) *bright idea* , a rope and tie it with either a clove hitch or a snarling wedge snotter knot *dunno2* ?
Me thinks we may have been here before *smile*.
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Replaced my Triumph 4 spring type clutch which has been on the bike for about 50 years with a new SRM one.
My old clutch worked fine. Used all manner of oils over the years including ATF. Never slipped and was easy to set up. Was a bit worn though.
The new clutch has been problematic. Have tried various grades of oil and get about 600 miles or so before it starts to slip. Have just adjusted it again and note I have to screw the clutch nuts in much more than SRM suggests.
Have one of Steve McFarlane's electric starters fitted and he says "I recommend automatic transmission fluid for this as it helps to stop the plates from sticking". So who is "right"?
Will be interesting to see if my clutch has bedded in or starts to slip again. i wonder if I have the wrong cups and springs or perhaps the plates have been contaminated. Time will tell.
Thinking of putting the old plates back in with their cups and springs.
Just my experience.
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I have just stripped, cleaned and refitted the four plate (non SRM) clutch on my SR and it was full of sticky black residue, I think contributing towards clutch drag and difficulty engaging neutral with the engine running.
I originally used straight 40 oil in the chaincase but I did some research on alternatives. Most ATFs have friction inhibitors which is the last thing you would want on clutch plates. When I looked at the Castrol website, the red TQF is an older formualtion which does not have these friction inhibitors and is recommended by Castrol for motorcycle primary drives.
Being red it is also useful to identify where the leaks are coming from *smile*
I have only taken it out once since and the clutch did not slip and felt good and neutral was easy to find after a 15 mile ride although that could have been partly due to making sure the pressure plate lifted evenly and slackening the far too tight primary chain.
I am not saying that SRM are wrong in not recommending modern ATFs, but Castrol are saying differently regarding the older TQF.
Who can you believe?
Jim
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This thread is timely for me as my SRM clutch is just beginning to slip a bit under hard acceleration (is there another kind?) so I am guessing the plates have bedded in and time now to adjust it. Correct amount of play in the cable.
A knowledgeable mate recommended ATF as it lubricates the primary chain better than oil he reckoned. But he wouldn't have known that SRM say not to use it so methinks I will stick to mineral oil.
I have only done about a thousand miles since fitting the SRM clutch and it transformed the bike allowing me to easily find neutral and a really light action. Should I need to adjust the clutch after such a low mileage?
Brian
PS Whilst working up the enthusiasm to do the job, I have ordered some washers to go under the case screws as I recollect "someone" recommending - these are they apparently - 5/16ths x 1/2" - first of the two here https://stainlessmiddleton.co.uk/search?controller=search&orderby=position&orderway=desc&search_query=Small+O.D.+Washers+5%2F16+x+1%2F2&submit_search= (https://stainlessmiddleton.co.uk/search?controller=search&orderby=position&orderway=desc&search_query=Small+O.D.+Washers+5%2F16+x+1%2F2&submit_search=)
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G'day Brian.
Do you mean the primary cover screws? If so their 1/4" ID and I think 3/8" OD 1/32 thick.
67-1709 https://tinyurl.com/yao4rakk are fiber for the level and drain screws.
Cheers
Edit: Was thinking plunger, s/a have the three front ones 5/16".
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If it's any help?
I made it for my bike - 1960 GF.
I hope there isn't any mistakes in it.
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That's a useful list. I've saved it for reference. Don't know why I never bothered making my own (list, that is).
Richard L.
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Thanks Roger,
I will be putting my chaincase back on in a day or so, and I know the screws aren't quite right.
Colin
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I still haven't got my clutch Outer Cover back on yet. My Chaincase Screws seem to be all over the place in length. Goodness knows where they came from umpteen years ago. *dunno*
I decided to measure up everything from first principles, and came up with the following stuff. *computer*
Colins Screw Lengths - Measurements of what I have, including a new set of SS screws I purchased many years ago, and which have not been cut to length except for the three large screws.
BSA A10 SA Chaincase Screw Lengths Sketch - I measured the depths of the Outer Chaincase holes from the base of the Fillister screws down to the gasket surface (You may find this fairly useful). Then measured the depths of the threaded holes in the Inner Case. All holes except one had no bottom (No. 7 on the sketch), ie the threads carried through to the other side. The depth of the inner case was 22.9mm average. I did not bother to detail the three large holes, as they go through into the crankcase. I will just use the 5/16" x 2" screws provided. Muskrat - do you know how deep the crankcase thread is before the bolt hits the flywheel.?? ie the actual depth of the thread in the bare crankcase?
BSA A10 SA Chaincase Screw Summary - I have detailed on this sketch the maximum length of the screws (below the Head) before they bind in the bottom of the threaded hole, or otherwise stick out the back of the inner chaincase. Then rounded off these measurements to give a practical length of the screws, ignoring the thickness of the gasket.
Surprisingly, it was very similar to Rogers List, except that I could get away with a bit longer lengths on some of them.
Before I get cutting the new screws to length *work*, I might wait for you all to jump on me *grins* ( ie. provide some feedback).
Cheers Colin
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OOps,
Here is a sketch with the depths of the chaincase holes as mentioned. Just realised that the other sketch does not have these measurements.
BSA A10 SA Chaincase Screw Hole Depths - This is the depth of metal from Under the Fillister Head screws down to the gasket surface of the chaincase. Might be worth mentioning that to get this measurement, I placed the cover face-down on a flat surface (table), and used a 20mm length of brass tube to seat on the screw head bearing surface - long enough to stick the thin bit of the Vernier calipers down through this onto the flat surface (table), and the blunt bit on the top edge of the brass tube. Then subtracted the 20mm from the measurement.
I can imagine that not everybody's chaincase holes would have exactly the same depth. There is considerable scuffing of the screw head bearing surface, perhaps significant loss of metal from new.
Colin
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Excellent Colin *smile*.
Here's a diagram I made for myself when I changed all my screws so I didn't get myself in a muddle (as I often do *eek*).
In your chaincase diagram, screw no 7 bottoming out at 43mm. Would that be because it's coming up against the front section of a fully enclosed chaincase?
Mine is just a chainguard, so no front section to butt up against the back of the inner primary chaincase at that point.
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....I placed the cover face-down on a flat surface (table), and used a 20mm length of brass tube to seat on the screw head bearing surface - long enough to stick the thin bit of the Vernier calipers down through this onto the flat surface (table), and the blunt bit on the top edge of the brass tube. Then subtracted the 20mm from the measurement.....
A variation f that can be to stick a 3/8, 10mm (I think it may really be ~25/64") drill shank in the head hole and measure from the mating surface to the drill- saves all the maths (every one of them)
Also worth not having them protrude out the back of the inner case to gather dirt and crap to grind the threads on the way back out
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Roger,
I checked and the No.7 is a blind hole - or at least it was supposed to be. Some PO has tried to put in a full 1-3/4" screw and it pushed through a bit. See the photo Screw 7 Blind From Right Side. And a few more attachments:-
A photo of the screws (Cols Chaincase Screws After Cutting) after cutting two of the 1-3/4" back to 1-5/8" to suit your Medium application.
Then a photo of the finished screws laid out around the chaincase (Cols Final Screw Locations)
Finally, a pdf of the layout (Chaincase Screw Layout). In this pdf, you will notice that the actual screw lengths are a little less than the nominal length - eg. the large 2" screws are actually 48mm - not much but worth knowing if you have stripped a thread - perhaps a slightly longer screw will get you out of trouble. (But keeping Dutch's comment in mind).
A tedious exercise I hear you say? - but in a few years when dementia has set in it may be useful. Then again if dementia sets in I may not remember where to find this stuff. *grins*
Anyway, she is all back together now, so off for a ride as soon as the wind drops - it is howling here.! *cry* No not that sort.!
Colin
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My four spring clutch dragge with thicker oil, straight 40 after a case of need, cleaned the plates and refilled with straight 20 and OK now.
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Sav, this what I now use for my SRM 4-spring:-
https://www.ebay.co.uk/itm/5L-SAE-20-Monograde-Engine-Oil-SAE20-Classic-Motor-Oil-5-Litres-SAE-20W-/112556936365?hash=item1a34ea8cad
More info here:-
https://www.a7a10.net/forum/index.php?topic=13195.0
(Edit): Read Replies 3 and 6.
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I hope it's OK to tag onto this thread rather than start a new one.
I fitted an SRM clutch back along and it transformed my A10 – I am very pleased with it - particularly as it allowed me to find neutral when stationery *smile*
However, I am now experiencing slight clutch slip when opening the bike up and probably need to tighten up the springs now the plates have bedded in.
I found the SRM instructions saying that the springs should show approx. one coil over the spring cups as mine do. (Photos attached).
My question is how much of a turn or how many turns I can safely tighten the springs to stop the slip?
Many thanks
Brian
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G'day Brian.
That looks more like 1 1/2 coils. I'd set it to arrow in pic.
Cheers
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Hi Brian,
This is how mine are adjusted. Posted these photos on here:-
https://www.a7a10.net/forum/index.php?topic=13049.msg104031#msg104031
but I've attached them again here. I get no slip or drag, light finger pressure at lever and slips easily into neutral at stop.
However, Gary from SRM commented on the spring adjustment and oil here: https://www.a7a10.net/forum/index.php?topic=13099.msg104714#msg104714
(Hope the links work ok).
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Agree with Musky. It needs at least one maybe even two turns extra.
Clutch slip is unnecessary loss of power and only slows you down... *smile*
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Thanks guys! I also covered my back by emailing SRM and was surprised to get a very quick response from Gary - great customer service eh?
Anyways up, taking all the advice together, I have adjusted the springs to where Muskrat recommended and it took two turns.
I realise now that I hadn't screwed them in far enough on installation but my excuse is there was no picture on the SRM instruction sheet just the advice to leave a coil showing. My interpretation of that seems to have been wrong *sad2*
Just got to get it all back together again now. Broke the gasket getting the cover off but fortunately have a spare. Cleaning all the old gasket goo off the cover was fun - not.....
Brian
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G'day Brian.
Do you mean the primary cover screws? If so their 1/4" ID and I think 3/8" OD 1/32 thick.
67-1709 https://tinyurl.com/yao4rakk are fiber for the level and drain screws.
Cheers
Edit: Was thinking plunger, s/a have the three front ones 5/16".
You were right and the washers I bought (Small O.D. Washers 5/16 x 1/2) only fit on the front three screws and are loose on the rest. However, despite their reduced outside diameter, the washers still don't fit in the cover (on the big three screws) being just a tiny fraction too large OD. So basically that was not a good use of £7 *sad2* So the cover is going back on washerless!
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Brian,
I forget who said this on the Forum, but I got the tip to put gasket goo on the outer cover only. I did this recently, and used a thick Lithium-based grease on the inner cover. I stuck the gasket to the inner cover with grease, then put gasket goo (Red Loctite - can't remember the number) sparingly on the outer cover and screwed it on just firmly enough to ensure the Loctite would flatten out evenly. I tightened it later.
There has been no hint of a leak ( more than I can say for the felt seal behind the clutch though). Anyway, It has been off and on twice, and no damage to the gasket. Cleaning the inner case gasket surface is a matter of a quick wipe with a rag.
I cannot say how effective this will be in the long term - perhaps the grease will melt away over time and start to leak.??
BTW, I have had that tin of grease since I was a teenager. I found it in flood debris after the 1966 flood in the Hunter Valley.
I don't chuck away nuthin'. Not the sort of grease you would normally use for bikes.
Colin
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...the washers still don't fit in the cover (on the big three screws) being just a tiny fraction too large OD. So basically that was not a good use of £7 *sad2* So the cover is going back on washerless!
You could try this: put the washers on a screwdriver shaft and hold them against your bench grinder. The result may not be pretty but it will reduce the OD
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never needed fibre washer on there, just wonder if small rubber o ring would be better if you do need something
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Hi Bill and All,
On the 3 front screws I put a little non setting gasket goo on the threads (hylomar)
and no issues
the front 3 screws and the two inner 5/16 bolts are "structural" so need to be "tight"
John
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The gasket goo one side and grease the other sounds the way to go!
There is only one locating dowel for the cover (hope that's right!) so keeping the gasket in place whilst fitting a gooey cover will be interesting.
I am thinking of perhaps putting a couple of drill bits or studs loosely in a couple of places on the inner face to hold the gasket in place whilst I fit the cover.
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I apologise for my need to be nurse maided but, for some reason, I still don't feel confident in the work I do on my GF *conf*
This one is for RogerSB I guess.
Here are photos of my SRM clutch with the screws turned in two full turns. If they are now right then no wonder I had started to get clutch slip! I almost think the screws may need another turn in!
EDIT: I sent Gary at SRM a copy of the photos and he replied "Hi, look a tad too far in, I would say in between the first pic you sent, and 2nd pic you sent." so I need to back the screws out one turn.
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Hi Brian, looks about right to me. As Gary's comment to RoyC in the previous post he reckoned mine looked a tad too tight. I haven't re-adjusted because it's working great.
I did have some difficulty keeping the notches on all the spring cups located in the notches in the pressure plate as they kept jumping out when turning the adjusters on the bolts. Managed it in the end with perseverance. I don't know how important that is but it looks neater *smile*. (Edit): Also the adjuster were a devil to get started on the bolt threads - had to push on them really hard to get them started.
Is lever at handlebar easy to pull in and is the gearbox clutch arm parallel to gearbox cover joint (90 degrees to cable) when lever is pulled in?
Also with the non-flexing alloy pressure plate and the needle roller pushrod adjuster the pressure plate seems to be self centering when you disengage the clutch so no dial gauge or bits of wire really needed to adjust it - just make sure the amount the springs are showing all look to be the same. Worked fine for me.
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so keeping the gasket in place whilst fitting a gooey cover will be interesting.
Just put my cover on, thinnest film I could manage on both side, used all the screws to keep the gasket on and line up.
Heres hoping
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...the washers still don't fit in the cover (on the big three screws) being just a tiny fraction too large OD. So basically that was not a good use of £7 *sad2* So the cover is going back on washerless!
You could try this: put the washers on a screwdriver shaft and hold them against your bench grinder. The result may not be pretty but it will reduce the OD
That's exactly what I've done, but no washers on mine right now. Man, does that screwdriver get hot. Maybe it's mentioned earlier in this thread (can't see right now) but is there a source for washers that will fit under the 1/4" screw heads?
Richard L.
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Hold them in a vice and file them.
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I think I am making a meal of what should probably be a simple job!
The clutch springs are now adjusted as per Gary's recent advice and, following RogerSB's tip, I checked and the clutch arm is no longer at 90 degrees to the case when fully disengaged so I need to sort that out - which should be simple enough I hope! A tad easier to do whilst the cover is still off.
Just to add to the fun, the oil level tube on the drain plug seems quite a way down from where the chain runs so I measured its height (about 17mm) and compared it to the distance between the bottom of the chain and the case (about 22mm) - a difference of about 5mm.
I would have thought that the chain should at least be skimming the top of the oil for lubrication or am I over thinking this? Perhaps the movement of the bike sloshes the oil back and forth and lubes the chain that way?
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There is only one locating dowel for the cover (hope that's right!) so keeping the gasket in place whilst fitting a gooey cover will be interesting.
Me again Brian, I've amended my chaincase diagram to indicate the dowel positions by blue circles.
I always make my own gaskets. I buy Flexoid gasket paper, which comes in various thicknesses. Bought some last year 2m x 1/2m x 0.8mm thick for making cover gaskets. It cost £14 including postage.
This is a bit long winded but:-
My method is to lay the cover on the gasket paper and push down on the dowels to mark their positions on the paper. Then draw around the shape of the cover. Cut around the shape, about 1/2" or so away from the drawn outline and then cut or punch the dowel holes out. Lay the paper on the cover and fit the holes over the dowels to fix it in position. With a small ball peen hammer carefully tap on all the screw holes in turn and with a few taps it will cut through the gasket paper. The little hole pieces cut through with the hammer often sink (some don't get completely cut out) into the holes in the cover and this helps to hold the paper firmly in position to do the remainder. Then tap around the outside and inside edges of the cover to cut out the shape of the cover accurately. Nip out any holes not completely cut out. You'll then have a perfect gasket and usually better than the ones you buy.
I then prepare the cover for fitting by carefully spreading a thin layer of Blue Hylomer on the side of the gasket that goes on the cover mating surface and place the gasket on it. Then do the same on the exposed (dry) side of the gasket. Smear a thin layer of grease on the inner chaincase metal mating surface and fit the outer cover and loosely fit all the screws until the joint is closed but not tight. Leave it for a bit (have a cup of tea) to allow the gasket cement to thicken (Blue Hylomer never dries solid) and then tighten the screws. Job done. I never get a leak from the chaincase joint - only a tiny amount from the drain plug sometimes, even when I fit new fibre washers *eek*.
The grease allows you to remove the cover easily again with the gasket undamaged and still stuck to the cover *smile*.
A mechanic friend of mine showed me how to do this about 40 years ago when I used to rebuild my classic car engines. It was in the days when they often made their own gaskets in garages.
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G'day Brian.
To adjust the lever arm position there is a screw and locknut under the oval cover on the other side near the footpeg.
Cheers
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Just to add to the fun, the oil level tube on the drain plug seems quite a way down from where the chain runs
The oil level tube looks about right to me Brian. You can check when you've fitted the cover by fitting just the oil level bit first and adding the correct quantity of oil (8 fl oz / 225cc). A little oil usually runs out of mine until it's level with the top of the tube, then I fit the bottom part.
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As I have said in previous posts SRM recommend 190cc of oil in the chain case and no more. *smiley4*
ELLIS
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As I have said in previous posts SRM recommend 190cc of oil in the chain case and no more. *smiley4*
ELLIS
Yes, they do Ellis, but my suggestion was a way for Brian to find out if his level tube is the correct length (without having to know what its length should be). He will have to fill it with BSAs recommended quantity of 8 fl oz to do that. Easy enough to drain it out and put back what he wants.
However, I've always put in 8 fl oz and I've not had a problem. I have SAE 20 mineral oil in the chaincase as recommended by SRM.
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Me again Brian, I've amended my chaincase diagram to indicate the dowel positions by blue circles.
That's brilliant. Not only has it showed me I have a dowel missing but, when I checked my bolts, I have all the right sizes but not in the right places! (Shades of Andrew Preview for those old enough to remember that M&W sketch) Did the swap over and all good now. I guess the threaded section in the crankcase for the S bolts must be forgiving enough to allow the M bolts to fit as I wasn't aware any were binding.
I am pretty sure I got 'em right now - photo is of the reverse of the bolts so opposite way around to the diagram of course ;)
I seem to have accumulated some spare gaskets so will use them first but may well try your Hylomar technique!
I have a problem with the clutch lever in that to get it at 90 degrees I have more slack cable than, ideally, I can take up with the adjuster. I may not have shortened the internal pushrod sufficiently when I fitted the SRM clutch unit - at least that's what I hope rather than have cut it too short!
I will go with what SRM recommend as far as quantity of oil but that seems to leave the chain hanging even further away from the oil. But we gotta assume SRM know what they are talking about having done the R&D.
EDIT1: I have searched the fiche on the Draganfly site in vain and can't find the page that includes the dowels to get a part number. Can anyone help please?
EDIT2: I went to bed thinking of my GF clutch! I realise now that I am being daft and that the length of the pushrod has b*gger all to do with the slack on the clutch cable! So I need to work out what to do as, when the clutch arm is at 90 degrees, the adjuster on the gearbox would have to be right out to take up the slack. No adjuster at the lever. Surely a cable wouldn't have stretched that much over the years? I see that a new cable is nearly £30 with p&p but am wondering how hard it would be to shorten the existing cable and re-solder one of the ends (but which one?)? If I have to buy new, can anyone recommend a quality item please as I know from similar purchases in the past that cables can be variable. Advice appreciated - as usual!
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Below from the factory parts book - 66 3074
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An 8mm dowel from a TTR250 camshaft cap will do the trick so at least I won't be held up by a missing dowel - just the cable and adjuster to sort out now ;)
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dowel posts came just a tad too late for me, I have no dowels whatsoever on the primary case, don't think I'm taking it off again to check or fit tho *smiley4*
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Getting there but another question on clutch adjustment!
I can't find anything in the Haynes manual or the BSA Instruction Manual that says what play (if any) there should be at the gearbox-end lever. Should it be tight up against push rod or just a small amount of clearance please?
I think my lever is slightly offset as it doesn't set at 90 degrees to the gearbox case when its adjusting screw and nut are parallel to the case. If the lever is at 90 degrees then the screw is at an angle to the push rod. Does that make sense?
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Should it be tight up against push rod or just a small amount of clearance please?
Clutch will warm up with use ( which is why neutral sometimes gets hard to find) so if you set it up with no play then then clutch rod will bear on the pressure plate and the actuating arm will also be in contact with the pushrod, everything will be touching - not good.
Allow what clearance you think is right, then stop after a good distance and check, easy enough to give a bit more at the lever
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Hi Brian,
Mine was the same. You can reposition it on the splines after removing the cover, split pin and nut (see pic).
Adjust the adjuster at gearbox so there's some free play between the ball bearing and the end of the pushrod when its up against the clutch pusher at the other end. It will also affect free play at the handlebar control lever.
I like to have a good 1/8" free play at lever - for me it feels more comfortable to operate).
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Hi All,
Brian and anyone else with the SRM pressure plate
You can adust the pushrod length (within limits) with the adjuster on the pressure plate
A clutch slippage problem can arise when the SRM "pusher" butts up against the end of the gearbox mainshaft (or nut)
(this can happen if the pushrod was cut a bit short) in this case pushrod free play may be still "look OK" but there is no play at the clutch end *ex*
John
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You can adjust the pushrod length (within limits) with the adjuster on the pressure plate
I wondered about that seeing a screwdriver slot in the end of the stud, however decided not to alter it due to nothing in the instructions I could recall.
Although my SRM pressure plate is I reckon an early one, it has a rough cast finish and SRM Devimead cast in to it
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Hi Bill,
Although my SRM pressure plate is I reckon an early one, it has a rough cast finish and SRM Devimead cast in to it
That's the same as the one in my SR
I have fitted several of the later machined ones to other bikes
I have bought the adjusters bearings and pusher's as spares and adapted the bearing arrangement into other make pressure plates with success *smile*
John
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I have bought the adjusters bearings and pusher's as spares and adapted the bearing arrangement into other make pressure plates with success *smile*John
interesting - my other bike has an alloy pressure plate from (IIRC) Lightning spares (are they still around or do I remember some one taking there stuff over?)
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.........Lightning spares (are they still around or do I remember some one taking there stuff over?)
Fairly sure that Draganfly bought them out
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Machined alloy, non SRM, pressure plates are listed in the 2013 wassel catalogue, probably still in the new one so I suspect most dealers sell them.
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Thanks again for the help and advice chaps!
Following an enforced break I realised that I can drive and ride again from Tuesday so put my mind to re-assembling Flash today.
I have just put the primary chain cover back on after having adjusted the clutch and, unfortunately, the crankcase threads for one of the bolts feels like it's about to strip.
The threaded section goes right through to the outside world so I can fit a longer bolt that will catch on good threads but, where to find such an odd Imperial beasty?
The original is a 1/4" x 1.3/4" x 20 tpi Allen/Socket/Cap headed screw that is not threaded along its whole length.
Ideally I would like to find a bolt at least quarter of an inch longer. Anyone got such a thing or can advise where I might get one please?
Also, I haven't sourced SAE20 oil as recommended to use by SRM. Could I use Fuchs Silkolene Super 4 10W-40 semi-synthetic oil which is suitable for wet clutches instead (I use it in my TTR250).
Brian
PS I bet we get a fortnight of rain starting Tuesday :-(
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Its just a 1/4 x 20 tpi Whitworth (BSW) thread.
https://www.ebay.co.uk/itm/1-4-X-1-3-4-UNC-BSW-CAP-HEAD-SOCKET-SCREW-BOLTS-STAINLESS-UCB11-25-14/253164497210?hash=item3af1c7a93a:g:Ozk
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Thanks Julian - I will get a pack ordered!
Regarding the oil, I emailed Gary at SRM and he replied:
"Hello Brian,
I think the 10w-40 will be fine for your clutch, its only 1/3 pint, approx 190cc/ml.
Hope that you manage to get some miles in before the weather gets worse.
Regards Gary"
So I should be good to go for tomorrow ;-)
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I see it's been a little while since my last post so here's the update.
After taking off the cover and tightening the clutch springs (I hadn't realised at that point that I could do it without taking off the cover!) I put it back together and took the A10 out for a test run and the clutch slip was worse than before *sad2*
I tightened the clutch springs through the inspection window on the cover (why hadn't I thought of doing this before!) but it made no difference.
Despite checking (or so I thought I had!), I believe that I had adjusted the SRM "pusher" incorrectly and reminded myself of John's (chaterlea25) advice from 11th August:
"A clutch slippage problem can arise when the SRM "pusher" butts up against the end of the gearbox mainshaft (or nut)
(this can happen if the pushrod was cut a bit short) in this case pushrod free play may be still "look OK" but there is no play at the clutch end *ex*"
I have slackened the pusher off and re-assembled everything and I appear to have no slippage. If (whilst riding) I pull in the clutch in top gear, rev the engine and drop the clutch the revs immediately drop so I am thinking I am OK - fingers crossed. Thanks John!!!!
A couple of things arose.
Firstly, I tried the Hylomar on both sides of the cover gasket and greasing the engine side but it didn't work for me. When I took the cover off, the gasket actually separated along most of its length leaving half on the engine side and the other half on the cover. Maybe I didn't put enough grease on the engine side? Anyways up, I might just Hylomar the cover side next time. I think I have got away with re-using the old gasket this time around but a leak check this morning will tell me having put clean newspaper underneath after my test ride yesterday.
Secondly, I bought a pack of 2" bolts from eBay, https://www.ebay.co.uk/itm/1-4-X-2-UNC-BSW-CAP-HEAD-SOCKET-SCREW-BOLTS-UCB11-25-16/112229104834?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2057872.m2749.l2649, and used one to replace a damaged bolt and the length was perfect - see photo below to compare old and new. the end of the bolt just shows through the engine side casing so hasn't got spare thread hanging out to get rusty. Thanks for the tip Julian!
Shame the weather has turned as I am a fair weather rider so further "testing" is on hold until the sun re-appears.
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Kicking the bike over with clutch lever pulled in before starting is as natural to me as breathing. I ALWAYS do it. And most of my bikes (certainly all the BSA's) need it. You can feel it free off. Beats smashing first gear when going to move off. And in my case it's not caused by oil, because I don't use oil in my primary chaincases, I merely oil the chain occasionally and, around every 3,000 miles or so, take it off and boil in grease. That's a choice I made many years ago when I was having grief with my Triton. Remove the primary cover, strip clutch and wash plates in petrol, re-assemble, add oil and use. And two days later the same, because the plates slipped just sufficiently on kickstarting to prevent 'striking a light'. OK, it was a high compression motor with 3134 cams etc, but who wants a bike that won't start? I've had to get push starts on that thing just to get home. That, coupled with an alternator which couldn't keep up with the lights and a frame I didn't like meant I sold that bike within a year.
Why do you think BSA went to the trouble of a fully covered clutch on some models? It is a dry clutch running in a wet environment. If it was meant to run in oil the plates would either be cork or bronze.
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Unfortunately, my SRM clutch started to slip again so I stripped it right out to check the plates and they all look OK although a bit blackened - see attached photo. I hope they were OK to re-use as a new set is over £130 and these have done less than 1,200 miles.
I also attach a photo showing the pushrod and wonder if maybe I didn't cut enough off on the original installation?
I rebuilt the clutch with just a tad over the quarter turn of free play on the centre adjusting nut and all seemed fine on a test ride.
Yesterday was our Club's annual Dartmoor run and my A10 covered the 100 miles without any clutch slip including carrying a pillion passenger for the last 40 miles whose own bike had broken down.
I parked the A10 up whilst the awards ceremony etc took place so it had pretty much cooled down by the time I came to leave. I hadn't gone far and it was apparent that the clutch had started to slip again quite badly.
I hope to be getting the clutch cover off again later to see what's happening but what should I be looking for - what are the most likely mistakes that I could have made on the last clutch rebuild?
Brian
PS Question - is the clutch supposed to run dry (like mine seems to be) and the crankcase oil confine itself to lubing the primary chain?
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Replaced my Triumph 4 spring type clutch which has been on the bike for about 50 years with a new SRM one.
The new clutch has been problematic. Have tried various grades of oil and get about 600 miles or so before it starts to slip. Have just adjusted it again and note I have to screw the clutch nuts in much more than SRM suggests.
Will be interesting to see if my clutch has bedded in or starts to slip again. i wonder if I have the wrong cups and springs or perhaps the plates have been contaminated. Time will tell.
Thinking of putting the old plates back in with their cups and springs.
Just my experience.
Did you get your SRM clutch sorted Keith and, if so, what was the cause of the re-occurrence of the slipping please? I have the same symptoms unfortunately *sad2*
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.........PS Question - is the clutch supposed to run dry (like mine seems to be) and the crankcase oil confine itself to lubing the primary chain?
yeah sumthin like that...now where was I..... *conf2* sidetracked with a anti-something with the offspring (conspiracy theories)......Brian, sometimes you just need to fufufufufu with these thing s until you work it out.... *pull hair out*
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Hi Brian, sorry to hear your still struggling with your clutch.
When I fitted my SRM 4-spring, in 2017, I made up an instruction sheet (based on SRMs fitting instructions) for myself to follow and for my future reference and thought it may be of some help to you.
Bear in mind what I bought from SRM was a complete SRM clutch assembly (so there's no mix of parts).
Also I'm using 8 fl oz (225 cc) straight monograde SAE 20 in the chaincase, which is more than Gary at SRM recommends for their clutch and after 2 years, more often riding two up, I don't get any slip.
If my bike is left unused for any length of time, which isn't very often, the clutch plates can stick together. I try to make a point of riding, or at least moving and starting, my bike every couple of weeks - both summer and winter. However, there are times when that's not possible or just doesn't get done. So, every time I put my bike to bed, to counteract the chance of the plates sticking together, I pull the clutch lever in and slip a pre-adjusted cable tie (kept handy for just that purpose) over the lever and the handlebar grip to disengage the clutch 'just enough' so that the plates are held separated. Otherwise I have done, as RDfella always does, pull in the clutch lever to make sure the plates are free before kicking it over.
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What an excellent idea Roger - the SRM instructions are a tad all over the place! Is there a second page to yours please?
I think I know what I did wrong to cause my clutch to slip. I followed what I thought were the A10 instructions and only adjusted the centre fixing to a quarter of a turn when Gary tells me it should have been a full turn of free play *eek*
I followed section 9 of the instructions instead of section 7 - see here http://www.shop.srmclassicbikes.com/sites/default/files/downloads/SRM-PP-A4.pdf (http://www.shop.srmclassicbikes.com/sites/default/files/downloads/SRM-PP-A4.pdf)
Also he confirms the clutch plates should not be run dry. However, by using the SRM recommended 190cc no oil seems to get on my plates. So I am going to put enough oil in to overflow at the level screw. Will that be 225cc? I will check ;-)
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What an excellent idea Roger - the SRM instructions are a tad all over the place! Is there a second page to yours please?
I think I know what I did wrong to cause my clutch to slip. I followed what I thought were the A10 instructions and only adjusted the centre fixing to a quarter of a turn when Gary tells me it should have been a full turn of free play *eek*
I followed section 9 of the instructions instead of section 7 - see here http://www.shop.srmclassicbikes.com/sites/default/files/downloads/SRM-PP-A4.pdf (http://www.shop.srmclassicbikes.com/sites/default/files/downloads/SRM-PP-A4.pdf)
Also he confirms the clutch plates should not be run dry. However, by using the SRM recommended 190cc no oil seems to get on my plates. So I am going to put enough oil in to overflow at the level screw. Will that be 225cc? I will check ;-)
Hi Brian, I'm pleased it may be of some help to you. Attached is what I got from SRM with my clutch, so you can see why I made up my own to follow.
There is only one page Brian, just covers the fitting and the push rod/pusher adjustment.
The important thing is to make sure the adjusting arm on gearbox is at 90 degrees to the pushrod when control lever is pulled in (clutch disengaged). About half way in to fully in is the best place, so it leaves some room for adjustment later. When the lever is released fully (so clutch is engaged) and with the pushrod firmly up against the pusher in the pressure plate you need a little 'rocking' free play between the end of the pushrod at the gearbox end and the adjusting lever's ball bearing. Secondary adjustment, if needed, can be made to the pusher's adjustment on the pressure plate and finally at the handlebar lever. I personally like about 1/8" free play at the handlebar lever. I only ever need to pull the lever in half way (if that) to disengage the clutch.
(Edit): 225 cc is BSA's recommended amount and at that point it should start to overflow the drain plug's tube. This, of course, will be dependant on the metal washers, fibre washers, etc. fitted to the drain plug (to stop it leaking), which will obviously adjust the level of the tube inside.
Good luck.
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If my bike is left unused for any length of time, which isn't very often, the clutch plates can stick together. So, every time I put my bike to bed, to counteract the chance of the plates sticking together, I pull the clutch lever in and slip a pre-adjusted cable tie (kept handy for just that purpose) over the lever and the handlebar grip to disengage the clutch 'just enough' so that the plates are held separated. Otherwise I have done, as RDfella always does, pull in the clutch lever to make sure the plates are free before kicking it over.
I do that with a strip of velcro but the plates still stick together.
I have to kick it over a couple of times with the lever pulled in until the clutch plates separate. It's a PITA.
I also use straight mono-grade SAE 20 oil.
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I do that with a strip of velcro but the plates still stick together.
I have to kick it over a couple of times with the lever pulled in until the clutch plates separate. It's a PITA.
I also use straight mono-grade SAE 20 oil.
Hi Roy, To adjust the cable tie in the right place I originally fitted it so that I could depress the kick start without it turning the engine over (i.e. so clutch plates are disengaged). Velcro may be a bit hit and miss each time unless you keep it stuck together in the same place so you have the same lever adjustment every time.
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It was instruction 13 that caused my problem Roger *sad2*
For the A10 the adjusting screw needs to be one full turn out according to Gary who told me "adjustment at 1/4 turn would not have accounted for expanding friction plates when engine got hot, could be why they slipped, hence the one full turn on centre adjuster for clearance."
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As I have said in previous posts SRM recommend 190cc of oil in the chain case and no more. *smiley4*
ELLIS
I mentioned in my recent email to SRM's Gary that when I used 190cc of oil it wasn't wetting the clutch and asked if I should use the BSA recommended 225cc instead. He replied "There is an oil level screw, look on inside of outer cover and you will see a cutaway where the screw come through to gasket face, that will be the level screw, fit cover, leave that screw out, fill until oil comes out of the hole, then fit screw." so SRM aren't quite so dead set on the 190ccs after all. ;)
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My G/Flash, being 1960, has the two part combined drain and level plug that screws into the bottom of the chaincase. That's what I was referring to re fibre washers etc. Sorry Brian, I didn't clock that your bike was 1955 and will have separate drain and level screws in the bottom run of fixing screws. If your A10 is a swinging arm it'll still hold 225cc of oil and it'll be at that level when it stops running out of the level screw hole.
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Hi Roger.
I may have got a later cover as I have the two-piece level plug as well ;-)
Brian
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Hi Brian, yes you'll have the later cover then. To drain off any overfilled oil you just remove the small nut only. When the oil level inside the chaincase gets to the same height as the top of the tube it'll stop running out and that means the oil level is correct. Undo the big nut to remove the whole plug if you want to drain all the oil out.
(Edit): Gary obviously assumed you had the earlier chaincase.
Also Brian your tube looks a bit short to me (I may be wrong). From memory it should be 7/8", but I'd check it by measuring 8 fl oz (225 cc) in a measuring jug and pour it in through the inspection cover, remove the small nut on the plug and catch any oil that runs out (on level ground and on main stand). If its a lot it'll prove the tube is too short. Then you can pour the oil back in and you'll know your level is correct and whether the tube is the correct length, or not.
(Edit, edit):- Here's something to consider *eek* :_
https://www.a7a10.net/forum/index.php?topic=10861.msg81435#msg81435
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For what it's worth, if you look down through the inspection hole the oil-level-boss and oil can be easily seen, so no real need to undo the screw and make a mess- principle is no different to the Plunger models like mine and close enough is good enough (a bright light is needed, I shine sun in via a small mirror *smile*)
This also helps for just checking it periodically for level, and I need to add a bit regularly- it must evaporate *conf2*
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Replaced my Triumph 4 spring type clutch which has been on the bike for about 50 years with a new SRM one.
The new clutch has been problematic. Have tried various grades of oil and get about 600 miles or so before it starts to slip. Have just adjusted it again and note I have to screw the clutch nuts in much more than SRM suggests.
Will be interesting to see if my clutch has bedded in or starts to slip again. i wonder if I have the wrong cups and springs or perhaps the plates have been contaminated. Time will tell.
Thinking of putting the old plates back in with their cups and springs.
Just my experience.
Did you get your SRM clutch sorted Keith and, if so, what was the cause of the re-occurrence of the slipping please? I have the same symptoms unfortunately *sad2*
Doesn't time fly. My clutch has started to slip again. Just replaced the oil in the primary side so perhaps that has something to do with it.
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Can't recall if I said but after another occurrence of the dreaded clutch slip, I bought a new set of friction plates, cut the shaft in half and put a ball bearing between the two halves and, so far, no slippage......
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Can't recall if I said but after another occurrence of the dreaded clutch slip, I bought a new set of friction plates, cut the shaft in half and put a ball bearing between the two halves and, so far, no slippage......
Glad it is working for you, how many miles have you done with this mod?
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About 500 miles - forgot to note mileage :-(
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About 500 miles - forgot to note mileage :-(
Not sure how many miles I've done, probably over a 1000. Fingers crossed for you. I have an electric starter fitted and that adds to the conundrum about type of oil and quantity! KBO.
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Hi Keith,
Was there a recommendation for the amount / grade of oil from the starter supplier? I am assuming it came from Steve McFarlane ?
The slipping clutch could easily be down to the type of oil you changed to ?
I saw a topic on Britbike where a Goldie owner was suffering from oil leaks after fitting a Pearson clutch, and adding the recommended 400ml of oil, as the Suzuki plates need to be kept in oil ?
I am curious to find out what will work as I am very likely to be going down the electric leg and Suzuki based clutch route soon
John
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Hi Keith,
Was there a recommendation for the amount / grade of oil from the starter supplier? I am assuming it came from Steve McFarlane ?
The slipping clutch could easily be down to the type of oil you changed to ?
I saw a topic on Britbike where a Goldie owner was suffering from oil leaks after fitting a Pearson clutch, and adding the recommended 400ml of oil, as the Suzuki plates need to be kept in oil ?
I am curious to find out what will work as I am very likely to be going down the electric leg and Suzuki based clutch route soon
John
Steve's says ATF fluid with his starter, SRM say to use monograde engine oil with their clutch. With my original clutch, I've used ATF, Mono and Multigrade with no issues. Have also had to screw the clutch springs in much further than SRM say. Be interesting to see what is going on when I take it apart.
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Are SRM plates Surflex?
I had so much slipping under power with Surflex plates (in a Tony Hayward belt kit) with a dark friction lining material, that I could not understand why other people weren’t having the same problems.
As soon as any oil, of any kind or grade, got onto the plates, they slipped like Hell.
Removing the lining material (surprisingly easy with a penknife) and gluing cork mat in its place, put a stop to all slipping. The spring adjuster nuts are now backed well off, for a light action.
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If you want oil in your primary, then cork plates are the answer (thought they were only to be found on some old clutch baskets, not individual plates) because friction is virtually unaffected by oil. In fact, cork plates shouldn't be run dry. Old two strokes (eg Villiers) had cork clutches and no problem (apart from leaks) with oil in primary.
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Took to clutch apart. All looked good, some oil on the plates but just looked normal to me. Someone suggested both types of plates may be glazed. So have cleaned them and given them a light "roughen" with emery cloth. Now deciding between straight SAE20 or ATF Type F. Have ordered both but think I will try the SAE20 mineral monograde first. Back up plan is to try some super friction plates from a Triumph spares company like LP Willams. Fingers crossed.
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I have found there is just enough space to fit 6 bonded plates plus one extra plain plate from a 7 plate conversion in the SRM clutch. These plates appear to have some bronze in the bonded material.
If you use an alloy chainwheel and remove the lip from the centre drum you can fit all 7 plates of the conversion.
Photo shows Aerco plate compared with Surflex.
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I have found there is just enough space to fit 6 bonded plates plus one extra plain plate from a 7 plate conversion in the SRM clutch. These plates appear to have some bronze in the bonded material.
Photo shows Aerco plate compared with Surflex.
I guess the Aerco plates are the next ones I should try. Are they for wet or dry clutches? Should I be able to just change over the friction plates instead of going for the full 7 plate option?
Thanks
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Wet. I always use SAE 20 oil, having got some slip with ATF 7 or 8 years back.
You should be able to put 6 straight in, though I did find that they were a quite tight on outside diameter in one chainwheel but OK in another.
The bonded material is obviously thinner than a standard plate.
I did not try 7 plates in a steel chainwheel because I was not convinced that the rivetted construction was suitable for it. hence the alloy chainwheel. I would not have considered using 7 plates without the SRM thrust washer. Removal of the lip (quite soft I filed it off) on the centre drum is to allow the first plate in (bonded) to seat square on the chainwheel inner surface.
I think there are several options/makers of the 7 plate clutch kits, which include an extra plain plate plate. Dont go for the early 4 spring A65 version which includes a plain plate with different shaped tongues which are not compatible with the A10 4 spring.
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I use tractor universal 10W-30. It's cheap (great!) but not only is it a diesel engine oil, it is also suitable for hydraulics and most importantly for tractor oil-immersed brakes. No anti-friction additives. Ideal for oily clutches.
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Wet. I always use SAE 20 oil, having got some slip with ATF 7 or 8 years back.
Isn't the BSA clutch a "dry" one? Didn't think it was a wet clutch, it just happens to have oil around it? It is essentially the same as the plunger one which had a cover on it and that was a dry clutch. What type of ATF did you have problems with? Was it Type F? Thanks
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The 4 spring clutch is a Triumph design which was introduced in the 1930s.
Triumph workshop manuals over the years tell us that these are clutchs are designed to operate in oil.
Regret II dont recall which of the many formulas of ATF I used.
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Maybe the manual says the clutch can run in oil, but then the scribe didn't have to start / ride a bike with a slipping clutch. And why did BSA fit a dome over some of its clutches to keep the oil out? I disagree with the manual's advice and can say I 've always had trouble with slipping clutches (BSA / Norton / Triumph) whenever I've had oil in the primary. Strangely, my Velocette never complained too much, but then the cases used to leak (and were such a bugger to put together) that there probably wasn't any oil in there anyway.
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Had the same 4 spring Triumph type clutch in my A10 for forty or so years. Never had slip problems. Used ATF, but mainly 20W-50. Fitted the "improved" SRM one and at the same time an electric starter about 5 years ago when completely rebuilt the bike. Had issues since. Bought some replacement friction plates must be thirty plus years ago and still have them. May fit them to see if they are an improvement on the modern SRM ones. Look the same to me though. Interesting times working out what's likely to work and the best combination. Sometimes wonder if better to leave it standard but should be able to improve on what was designed all those years ago surely? Surely if the clutches were designed to run in oil, there would not be so much concern about the quantity of oil in the chain case? It is said the oil is there to mainly to lubricate the chain.
I've run Suzuki clutches on my Vincent when I had it. Modified the clutch housing to allow oil to enter. Used various oils with no slipping problems. Problem there was getting enough oil to it! However, I think they are "wet clutches". KBO!
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Ha! The ongoing clutch saga....
Here’s my experience; I used to run a straight hydraulic ISO 32 oil in the primary cases of both the plunger (6 spring) and the SA (4 spring). This oil came out best after experimenting with different oils.
The plunger clutch always ran fine, but the SA clutch kept having a tendency to stick, so I changed both to ATF fluid.
This made no change to the plunger clutch, but it made the SA clutch slip and made no change to the sticking.
I changed the SA back to hydraulic oil, this stopped the slipping but it’s still sticky. When I clean the plates it behaves flawless but after an hour drive it starts sticking again. When pulling the lever the clutch takes a couple of seconds to release, and if I select first gear too hasty it replies with a crunch. Careful setup and an SRM pressure plate improved matters but only up to a point.
Strange thing is that it’s only the outer plates that are oily and stick. Further up the basket the plates are bone dry and release straight away.
What puzzles me most is that I have the plunger clutch running without the clutch cover, so oil can get everywhere but it never sticks, while the SA has the (in)famous oil flinger which seems to do it’s job in keeping oil away (except from the first plates). I did an experiment with a chain wheel of which I removed the “flinger” but this only made things worse so back to square one.
Investigations ongoing....
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Morris, very interesting. Some thoughts, are the friction plates the same material? How do the spring pressures compare? How often and how many miles do the bikes cover in a year? How are the bikes ridden?
I wonder if the harder they are worked, less the problem?
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Hi Morris,
What is the pivot centre distance of your clutch lever?
If it is 7/8", then the clutch operation will be approx 25% lighter than a 1 1/8" centre / centre lever, but the plate movement will be same amount less.
I have found some clutches need the 1 1/8" lever to fully disengage when cold.
Richard
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Plain plates are often not completely flat, even new ones.
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If I recall correctly, Suzuki clutches can be fitted with plain plates which have lots of "dimples" or similar fine bumpy surface and used to improve the operation of the clutch. Perhaps thats why abrading plates makes ours work better until the abrading gets worn away?
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Hi Morris,
What is the pivot centre distance of your clutch lever?
Aha! Now there’s something! I just measured both levers and the SA has 7/8 while the plunger has a 1 1/4 pivot. *problem*
So many discussions about this issue, and it never occurred to me that this may explain my problem! *red*
Thanks for the tip Richard, I’ll swap the levers ASAP and see what comes out.
Regarding the plates, both came from the same supplier (which of course don’t mean that the friction material is the same as the plates are physically different and could come from a different source)
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Not reading the whole 9-page saga before posting in this topic.
I'm quite excited right now. SRM 4-spring clutch just arrived. It's going on the running A10 (not WHILE it's running) so that the 6-spring can go on the A7 in the works. One of my justifications is that the lower-powered A7 will do better with the 6-spring than the A10 does. New clutch may even be installed on the A10 in time for a weekend ride. Definitely before DGR.
Sooo pretty.
Richard L.
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Not reading the whole 9-page saga before posting in this topic.
I'm quite excited right now. SRM 4-spring clutch just arrived. It's going on the running A10 (not WHILE it's running) so that the 6-spring can go on the A7 in the works. One of my justifications is that the lower-powered A7 will do better with the 6-spring than the A10 does. New clutch may even be installed on the A10 in time for a weekend ride. Definitely before DGR.
Sooo pretty.
Richard L.
Hi Richard, I've been reading through this thread in preparation for fitting my new clutch parts (friction plates/plain plates/ billet pressure plate and release bearing etc.). I was wondering how you have got on with yours if indeed you've got around to fitting it yet *eek* as I know you've been busy with your other build and the lathe etc.
I have found the revised SRM notes to still be a bit of a dogs breakfast to be honest they seem to have some of the operations out of sequence still but I've got everything fitted now. (Thanks to Roger too for his notes, most helpful and confirmed my own thoughts.) After removing the chainwheel I found my previously fitted new adapter is not compatible with the SRM thrust bearing and would need to be removed and have a relief ground into it to replicate the SRM one. I decided this probably wasn't worth it so have left the thrust washer out. (I didn't buy a complete SRM clutch as I'd already changed a number of items previously)
Unfortunately at some stage in my deliberations my clutch cable outer must have moved and fell out of one of the ferrules which meant my measurements for cutting the push rod down were wrong! I might try the old cut in half and fit a steel ball in the middle trick as this will make up the difference, failing that I'll get another length of silver steel and start again! Certainly in no hurry to get the primary case back on at this stage...
Oh and as this topic included some discussion about oil levels I thought I'd have another look at that too.
The second photo shows my spirit level sitting, well level, as it were (yes I know in the picture it looks anything but but it was level honest, check the bubble!) and just nestling up underneath the chain wheel so that if the top surface represents the oil level in the case then the chain under the chain wheel would be totally immersed in the oil when stationary on the centrestand. My workshop floor is level but the bike sits up with its rear tire 3/4" (look at me, inches even *pull hair out*) off the deck so when on its wheels the chain would be probably at least 1/4" deeper in the oil. The level is sitting about 1/4" above the bottom face of that little impression in the rear cover that I assume is to assist taking the split link on and off although you don't actually need it. Handy though as you can see this feature with a pencil torch through the filler hole and thus you can visually see your oil level. I've now physically scratched a reference line here that I can use as my guide which will take all the mystery out of things..shame shame....
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i spy with my little eye a locking ring inside the cush nut same as i have on mine *bright idea*
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i spy with my little eye a locking ring inside the cush nut same as i have on mine *bright idea*
That’s right Bergs, I had an excess of bare threads doing nothing, a spare nut and a lathe so what else was a bloke to do? Double nutted and Loctited FTW! *smile*
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I have the SRM clutch on my Super Rocket and it is very light to use but slips and needs adjusting. Does anyone know what heavier springs can be used in them?
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Happy to report the SRM clutch all went in with no problems, I ended up with a 1/4" steel ball inserted between my push rod and the SRM top hat roller bearing release purely because my shortening of the pushrod went awry somehow! I think the push rod was caught on something internally which resulted in it sticking out further and not being fully seated home when I took the measurement. With hindsight I should have compared my amount to come off the pushrod with the length of the SRM added part as they should have been the same anyway the steel ball has saved the day although you need to be careful installing it as a loose steel ball in your gearbox wouldn't be ideal...
My test run today revealed the clutch to be light and very grippy almost too fierce at this stage so we'll see how it goes once I get used to it. Neutral is now a breeze to find either from first or second gear. In fact there is so little drag that I even had some difficulty getting it into first to pull away and there's no crunch at all. I'm running with 220cc of a multigrade 10W40 oil suitable for motorcycles with combined engine/gearboxes and clutches running in oil. From a dry fill this amount just came up to my previously scribed line on the inside of the primary inner cover which corresponds with the chainwheel teeth and chain just dipping (being covered). This also resulted in signs of oil being flicked around past the filler hole when the engine was revved and when I stopped it a drip formed under one of the links in the top run of the chain so its definitely getting enough lube. I will check this level after a couple more runs and see how it looks. no signs of leakage from the primary despite reusing the gasket which was pleasing too.
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Hi guys, I'm after advice from anyone who has fitted/is running one of these clutches (A10 SA. 4 spring). Everything is fine, the set up was easy and I followed the somewhat rambling SRM notes to the letter. The thing is whereas my old clutch was slipping this one is extremely fierce. It's like a light switch and hard to gauge with virtually no feel.
I tensioned the springs as instructed and have a full coil visible between the nuts and the pressure plate. I've ridden out 2 or 3 times since doing the job and there's been no change. It also feels a bit heavier than expected. I'm wondering whether I should back off the nuts by a turn and see how it goes. Luckily I have the later primary cover with the inspection plug so this is a quick job.
Is the clutch likely to improve with use (I would have thought not) if I leave alone or should I intervene? That's my question I guess. I figure it can't do any harm to try unless it starts slipping but that would be obvious immediately.
As ever grateful for any feedback. cheers BON
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BONails i'm not sure how to explain this and i haven't been to the pub!! some years ago my mates 4 spring on his triton was grabbing and we found he had the wrong parts or the right part that didn't go with the wrong part *lol* this was causing some lateral? movement making it grab as the clutch lever was released no matter how slow we tried to release the lever. if yours is ALL SRM then i haven't got a clue and i will sod off to the pub *beer thankyou for listening have a nice day *conf2*
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That's a good point Mr berger. When I rebuilt the primary I fitted new chainwheel/basket, hub, adaptor etc amongst a lot of other stuff and put the old plates and springs etc back in. At the time I was unsure what other issues I would be finding with the bike and didn't want to spend too much on it. These new parts came from Feked.
Everything fitted well and worked fine with the old clutch parts except I couldn't get the thing to stop slipping. Now I've changed the driving and driven plates, pressure plate, springs , nuts and cups. all parts from SRM. Everything fitted well and I could see no issues as it went together. These parts are all supposed to be compatible as SRM sells all of them separately.
When I built the clutch up I wiped all the plain plates with acetone in case they had anti corrosion product on them, then I rubbed them down gently on a sheet of fine wet & dry on a flat surface plate and found them very flat. Checked all around for burrs and sharp corners, all the usual things.
The clutch frees very readily, doesn't stick, doesn't drag at all. I can engage first gear from neutral with no crunch at all and similarly finding nuetral from first or second is a breeze, really impressive actually! Unfortunately though it is a bit grabby...
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Hi BagONails,
That grabiness you speak of should smooth out once you get a few miles on it. I find it common when I have the clutch clutch down for inspection and wash the plates in carb cleaner it does tend to be a little harsh for a few miles. Glad to hear it does not slip and finds neutral ok, sounds like you have a very good clutch now. *wink2*
ELLIS
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BONails maybe a set of photos with pictures of clutch centre on mainshaft of inner and outer drum and which plate you start with would help, also which way your putting the recessed washer on. my mate also built his one with a plain plate grinding away on the chainwheel *eek*. i do remember now he managed to split the washer when tightening up the nut because of the movement that was happening. he had got the recessed washer on the wrong way, i had to tell him the recess wasn't for the nut to sit in, it was to push everything into situ. as i say he had the wrong bits put together at one time but when everything was correct the washer on wrong was causing the snatch. at the time i knew nothing about 4 spring clutches but pointed out to him in engineering terms the washer recess wasn't for the nut to sit in. after much argument he turned the washer round and got a perfect clutch. he also made a brass thrust washer to try and get things right of course it didn't work *bash*
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My SRM clutch came with a thick plain washer to go under the nut, not a recessed one. Fits together fine works fine and chainwheel does not wobble because of the A65 type thrust washer.
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Ian, I remember after I replaced my 6 spring with SRM's 4 spring it felt very different and seemed to take up immediately and I felt it was a little too fierce at first, but in no time I got used to it and became unaware of it (like a headache you know when you have one but you can't remember when it disappears).
I've just checked my notes and I fitted my 4 spring on 25 Nov 2017 and I've not had to touch it since - and a sidecar has been fitted to my GF since 2019, so it's had to work hard.
Here's a pic of my clutch anti stick tool - in use and out of use ;D psst, You can buy them at Halfords *smile*.
Rog.
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Doesn't leaving the clutch cable under tension like that, over time, tend to stretch the cable Roger???
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Doesn't leaving the clutch cable under tension like that, over time, tend to stretch the cable Roger???
Clutch cables stretch. There’s an adjuster.
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Hi Jules, It's adjusted only just enough to separate the plates, so it's not pulled right in, that's the advantage of a cable tie, as it's the same adjustment every time. When you think of it all the cables come under a lot of strain every time they're used and as Triton Thrasher pointed out cables can be adjusted.
However, I only slip the cable tie over the lever when I know I won't be using my bike for a while. That usually means a week or two because I've always made a point of using my bike a least once every couple of weeks - if possible, including the winter. That's as long as it's not wet, as trying to be a good custodian of it I try to avoid getting it wet and dirty.
Rog.
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Thanks for all the info and somewhat reassuring experiences from some.
BONails maybe a set of photos with pictures of clutch centre on mainshaft of inner and outer drum and which plate you start with would help, also which way your putting the recessed washer on. my mate also built his one with a plain plate grinding away on the chainwheel *eek*. i do remember now he managed to split the washer when tightening up the nut because of the movement that was happening. he had got the recessed washer on the wrong way, i had to tell him the recess wasn't for the nut to sit in, it was to push everything into situ. as i say he had the wrong bits put together at one time but when everything was correct the washer on wrong was causing the snatch. at the time i knew nothing about 4 spring clutches but pointed out to him in engineering terms the washer recess wasn't for the nut to sit in. after much argument he turned the washer round and got a perfect clutch. he also made a brass thrust washer to try and get things right of course it didn't work *bash*
Berger, I'm hoping to avoid taking it all down again but we will see how it goes. I am pretty sure it is all assembled as it should be and I know for sure the dished washer is the correct way around! I actually bought the SRM thrust washer but found the Feked supplied chain-wheel and adapter did not allow me enough material to machine a register for it to run on so I didn't use it in the end. I doubt that being missing would affect the action too much. I think the thrust washer helps to keep the chain wheel running in line and would improve the clutch if you were suffering from drag, a problem I definitely don't have. This is also heartening for me in as much as my original problem was the clutch being out of alignment. The new adapter did not correct it sufficiently and I had to re-machine the taper to get the alignment I needed. The fact I have no drag at all suggests that everything is now very much in line and stays in line when the clutch is pulled in.
My SRM clutch came with a thick plain washer to go under the nut, not a recessed one. Fits together fine works fine and chainwheel does not wobble because of the A65 type thrust washer.
Julian, that is interesting, I didn't notice they supplied a different design of washer and they didn't mention it when I spoke to them. I explained I would have a mix of parts and they didn't expect any problems. So I put the dished washer back on...something to bear in mind if the issue doesn't improve with use. Thanks.
Ian, I remember after I replaced my 6 spring with SRM's 4 spring it felt very different and seemed to take up immediately and I felt it was a little too fierce at first, but in no time I got used to it and became unaware of it (like a headache you know when you have one but you can't remember when it disappears).
I've just checked my notes and I fitted my 4 spring on 25 Nov 2017 and I've not had to touch it since - and a sidecar has been fitted to my GF since 2019, so it's had to work hard.
Here's a pic of my clutch anti stick tool - in use and out of use ;D psst, You can buy them at Halfords *smile*.
Rog.
I know what you mean Rog and I think this may be behind the "improves with use" sentiment, does it really or do we just get used to it?
Good to hear you found it to be a bit fierce from new and even better to hear you have tested it well and had no problems *wink2*
Thanks too for your notes, earlier in this thread, I found them very handy in trying to interpret SRM's slightly arcane fitting instructions! Cheers
I'm going to keep riding it for now as there is nothing obviously wrong and see how it goes. I'm also using standard 10W40 engine oil for motorcycles with wet clutches in the primary just in case the ATF type F was to blame and paying close attention to oil levels etc. The old plates were not fouled with oil but they were very shiny and worn.
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Hi All
The thrust washer was introduced afaik when the clutch hub lip was done away with and the innermost plate
changed to a friction sitting at the back of the basket, this change meant that when the clutch is being released the pressure is on the chainwheel not the hub
I modified a friction plate to slide over the hub lip as I had fitted an SRM adaptor
however I still got some clutch slip when the engine hit 4.5k rpm
I now have fitted a solid hub instead of the shock absorber type and a 7 plate conversion
I do not have a lot of miles on this yet but it seem's a bit "grabby"
I assembled the plates dry but wonder if I should have very lightly oiled them?
John
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Hi John,
Your set up sounds quite different to mine, the only hubs I've seen without the lip is the A50/A65 version. That too runs a thrust washer as you have described. Sorry to hear you still had slippage after fitting a new clutch.
Here's a ref to the assembly photo on SRM site which shows the last closing plate being plain steel under the ally pressure plate. This clutch has 5 friction plates and 6 plain steel. If there is a plain steel at the top of the stack then there must be one at the bottom (against the lip).
http://www.shop.srmclassicbikes.com/product/triumph-pre-unit-4-spring-clutch-solid-centre-drum
The SRM hub for A7/A10 SA models with 4 spring clutches is this one
http://www.shop.srmclassicbikes.com/product/centre-drum-4-spring-type-a7-a10-swingarm
and it looks exactly the same as my Feked solid hub (made in England!) with a lip at the rear. I bought the standard plate stack from SRM (5 friction plates and 6 plain steel plates).
RogerSB put up a very good write up on his assy with a schematic showing where all the bits go. You can find that at reply #98 in this thread. The thrust washer is there but it goes to the rear of the basket between it and the adapter flange. You can see from his photo how much bigger the flange dia is to take the thrust washer. I guess it just takes up a lot of that excess clearance that allows the basket to wobble even when the hub is snugged up tight and the center nut is fully tightened.
So you would have 7 friction plates and 7 plain ones I gather if the first one is a friction plate at the rear against the basket. That would give you a lot more grip and I guess more grab but the spring load is spread over more area so maybe not.... I remember checking to see if I could possibly load another pair of plates into my set up but that would not have worked! The point about oiling the plates is interesting. Maybe a bit of oil would improve the feel and perhaps this does occur over time as there is hot oil mist around the plates the whole time she's running. My new plates were bone dry, grey and furry/fibrous to the touch.i.e. very grippy. The old ones were black shiny and appeared to have absorbed oil over time yet they were not wet with oil. They felt a lot more slippery to the touch.
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Converted my SRM clutch to 7 plate using Aerco plates.
First fitted an alloy chainwheel - the steel one was a bit worn, then filed off the lip off the hub (like the 1966 on A65 setup) it is quite soft. Then fettled the sleeve, the chainwheel and thrust washer so excess drag eliminated.
Inserted plate in first.
Thought about using a steel chainwheel but decided against it as the rivets used in the riveted assembly chainwheel/basket appeared to sit proud and slightly uneven to the chainwheel and I was concerned the plates might not sit squarely.
Works fine no grabbing but can take some force to free it off on the kickstarter first use of the day.
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Hi All,
BON, some of those "grey" plates are grabby as fu#k *eek*
Previously I had cleaned up the bottom of the chainwheel slots so a friction plate sits flat, it does not move relative to the chainwheel so don't worry about the rivits.
I bought the 7 plate kit from Burton bikes ,
The plates are thinner and have smaller friction area, but still barely fit into the
chainwheel
There's no hint of slip with the 7 plate conversion *smile*
John
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just to add , there's no hint of slip with a 6 spring if you want to crack brazil nuts between the finger and thumb *lol*, i'll get my coat i'm going to the pub again, it's my 11th birthday..... 11 years since i died in the front room.. sunday 27th march, my thunder rods were made on the 27th march also, very freaky.... glad to be here though *beer*
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Many happy returns, Keith. *yeah*
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.... glad to be here though *beer*
Bloody hell Berger well that is certainly a good excuse, if I could, I'd go to the pub with you. I have a mind to open an ale now in your honour...cheers, long life and happiness to you! *beer*
Hi All,
BON, some of those "grey" plates are grabby as fu#k *eek*
John
Well they are in there now John and I don't plan to buy any more so I guess I'll have to get to like them! There was plenty of what looked like bronze material in the mix so I'm hopeful they will improve with use. I'm going to try backing off the spring pre-load a little in the hope that a lighter action will make it easier to feel the bite point.
What do they call it? - 'modulation' yes I think that is what I need!