The BSA A7-A10 Forum

Technical => Clutch, Primary, Gearbox => Topic started by: RoyC on 19.06. 2018 21:20

Title: SRM clutch
Post by: RoyC on 19.06. 2018 21:20
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
Title: Re: SRM clutch
Post by: bsa-bill on 19.06. 2018 22:27
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
Title: Re: SRM clutch
Post by: RoyC on 19.06. 2018 22:54
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*
Title: Re: SRM clutch
Post by: muskrat on 20.06. 2018 08:52
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
Title: Re: SRM clutch
Post by: duTch on 20.06. 2018 09:34

 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
Title: Re: SRM clutch
Post by: RogerSB on 20.06. 2018 09:49
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.
Title: Re: SRM clutch
Post by: RoyC on 20.06. 2018 10:07
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*
Title: Re: SRM clutch
Post by: RogerSB on 20.06. 2018 10:25
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.
Title: Re: SRM clutch
Post by: berger on 20.06. 2018 11:45
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
Title: Re: SRM clutch
Post by: cyclobutch on 20.06. 2018 12:05
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.
Title: Re: SRM clutch
Post by: berger on 20.06. 2018 12:12
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*
Title: Re: SRM clutch
Post by: RogerSB on 20.06. 2018 12:31
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.
Title: Re: SRM clutch
Post by: RogerSB on 20.06. 2018 12:57
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.
Title: Re: SRM clutch
Post by: muskrat on 20.06. 2018 13:18
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
Title: Re: SRM clutch
Post by: RoyC on 20.06. 2018 14:04
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*

Title: Re: SRM clutch
Post by: RogerSB on 20.06. 2018 14:29
Oh well, at lease I have learned that there is nothing wrong with my SRM. *smiley4*

 *smile*
Title: Re: SRM clutch
Post by: cyclobutch on 20.06. 2018 14:51
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.
Title: Re: SRM clutch
Post by: Seabee on 20.06. 2018 20:41
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................
Title: Re: SRM clutch
Post by: cyclobutch on 21.06. 2018 08:51
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.
Title: Re: SRM clutch
Post by: RoyC on 21.06. 2018 09:05
I know that my plates are not contaminated, it's a new SRM clutch.
I am also using the recommended lubricant.
Title: Re: SRM clutch
Post by: duTch on 21.06. 2018 09:32

 [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
Title: Re: SRM clutch
Post by: KiwiGF on 21.06. 2018 09:47
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*

Title: Re: SRM clutch
Post by: RoyC on 21.06. 2018 10:33
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*
Title: Re: SRM clutch
Post by: Beeza on 21.06. 2018 10:48
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 ?
 
Title: Re: SRM clutch
Post by: RogerSB on 21.06. 2018 11:31
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*).
Title: Re: SRM clutch
Post by: Topdad on 21.06. 2018 11:42
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 ?
Title: Re: SRM clutch
Post by: berger on 21.06. 2018 12:36
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*
Title: Re: SRM clutch
Post by: RoyC on 21.06. 2018 14:22
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
Title: Re: SRM clutch
Post by: Greybeard on 21.06. 2018 14:36
Mmm.. I'll be interested to hear what our resident wizards make of that criticism of ATF in primaries
Title: Re: SRM clutch
Post by: RogerSB on 21.06. 2018 16:06
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*.
Title: Re: SRM clutch
Post by: CotswoldsA7 on 21.06. 2018 16:37
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. 👍😀
Title: Re: SRM clutch
Post by: chaterlea25 on 21.06. 2018 21:24
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
Title: Re: SRM clutch
Post by: metalflake11 on 22.06. 2018 02:11
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?
Title: Re: SRM clutch
Post by: orabanda on 22.06. 2018 02:12
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



Title: Re: SRM clutch
Post by: RoyC on 22.06. 2018 09:44
I've ordered this.

Title: Re: SRM clutch
Post by: morris on 22.06. 2018 13:03
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
Title: Re: SRM clutch
Post by: nimrod650 on 22.06. 2018 18:27
could you have a loop to slip over handlebar end to hold  lever in when stood ??
Title: Re: SRM clutch
Post by: a101960 on 22.06. 2018 19:15
Quote
could you have a loop to slip over handlebar end to hold  lever in when stood ??
Cable tie for instance.
Title: Re: SRM clutch
Post by: RoyC on 22.06. 2018 19:28
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.

Title: Re: SRM clutch
Post by: duTch on 22.06. 2018 23:19

 
Quote
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
Title: Re: SRM clutch
Post by: RogerSB on 23.06. 2018 10:19

 
Quote
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*.
Title: Re: SRM clutch
Post by: KeithJ on 26.07. 2018 16:45
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.




Title: Re: SRM clutch
Post by: lawnmowerman on 26.07. 2018 19:43
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




Title: Re: SRM clutch
Post by: BrianS on 27.07. 2018 13:10
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=)
Title: Re: SRM clutch
Post by: muskrat on 27.07. 2018 13:24
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".
Title: Re: SRM clutch
Post by: RogerSB on 27.07. 2018 18:40
If it's any help?
I made it for my bike - 1960 GF.
I hope there isn't any mistakes in it.
Title: Re: SRM clutch
Post by: RichardL on 28.07. 2018 06:34
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.
Title: Re: SRM clutch
Post by: Colsbeeza on 28.07. 2018 11:52
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
Title: Re: SRM clutch
Post by: Colsbeeza on 30.07. 2018 10:20
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
Title: Re: SRM clutch
Post by: Colsbeeza on 30.07. 2018 11:59
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
Title: Re: SRM clutch
Post by: RogerSB on 30.07. 2018 12:46
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.
Title: Re: SRM clutch
Post by: duTch on 30.07. 2018 14:28

 
Quote
....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
Title: Re: SRM clutch
Post by: Colsbeeza on 31.07. 2018 09:10
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

Title: Re: SRM clutch
Post by: Sav on 31.07. 2018 09:34
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.
Title: Re: SRM clutch
Post by: RogerSB on 31.07. 2018 09:55
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.
Title: Re: SRM clutch
Post by: BrianS on 09.08. 2018 17:14
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

Title: Re: SRM clutch
Post by: muskrat on 09.08. 2018 18:00
G'day Brian.
That looks more like 1 1/2 coils. I'd set it to arrow in pic.
Cheers
Title: Re: SRM clutch
Post by: RogerSB on 09.08. 2018 20:38
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).
Title: Re: SRM clutch
Post by: morris on 09.08. 2018 21:55
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*
Title: Re: SRM clutch
Post by: BrianS on 09.08. 2018 22:11
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
Title: Re: SRM clutch
Post by: BrianS on 09.08. 2018 22:20
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!
Title: Re: SRM clutch
Post by: Colsbeeza on 10.08. 2018 09:43
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
Title: Re: SRM clutch
Post by: Greybeard on 10.08. 2018 10:11
...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
Title: Re: SRM clutch
Post by: bsa-bill on 10.08. 2018 11:11
never needed fibre washer on there, just wonder if small rubber o ring would be better if you do need something
Title: Re: SRM clutch
Post by: chaterlea25 on 10.08. 2018 11:31
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
Title: Re: SRM clutch
Post by: BrianS on 10.08. 2018 13:31
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.
Title: Re: SRM clutch
Post by: BrianS on 10.08. 2018 14:26
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.
Title: Re: SRM clutch
Post by: RogerSB on 10.08. 2018 15:09
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.
Title: Re: SRM clutch
Post by: bsa-bill on 10.08. 2018 16:16
Quote
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
Title: Re: SRM clutch
Post by: RichardL on 10.08. 2018 16:39
...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.
Title: Re: SRM clutch
Post by: RoyC on 10.08. 2018 17:16
Hold them in a vice and file them.
Title: Re: SRM clutch
Post by: BrianS on 10.08. 2018 17:36
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?

Title: Re: SRM clutch
Post by: RogerSB on 10.08. 2018 17:52
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.
Title: Re: SRM clutch
Post by: muskrat on 10.08. 2018 17:58
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
Title: Re: SRM clutch
Post by: RogerSB on 10.08. 2018 18:09
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.
Title: Re: SRM clutch
Post by: ellis on 10.08. 2018 20:45
As I have said in previous posts SRM recommend 190cc of oil in the chain case and no more.   *smiley4*

ELLIS
Title: Re: SRM clutch
Post by: RogerSB on 10.08. 2018 21:01
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.
Title: Re: SRM clutch
Post by: BrianS on 10.08. 2018 21:35
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!
Title: Re: SRM clutch
Post by: JulianS on 10.08. 2018 22:42
Below from the factory parts book - 66 3074
Title: Re: SRM clutch
Post by: BrianS on 11.08. 2018 11:43
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  ;)
Title: Re: SRM clutch
Post by: bsa-bill on 11.08. 2018 12:21
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*
Title: Re: SRM clutch
Post by: BrianS on 11.08. 2018 13:44
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? 
Title: Re: SRM clutch
Post by: bsa-bill on 11.08. 2018 14:25
Quote
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
Title: Re: SRM clutch
Post by: RogerSB on 11.08. 2018 16:04
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).
Title: Re: SRM clutch
Post by: chaterlea25 on 11.08. 2018 19:33
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
Title: Re: SRM clutch
Post by: bsa-bill on 11.08. 2018 19:39
Quote
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
Title: Re: SRM clutch
Post by: chaterlea25 on 11.08. 2018 22:11
Hi Bill,
Quote
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
Title: Re: SRM clutch
Post by: bsa-bill on 12.08. 2018 09:26
Quote
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?)
Title: Re: SRM clutch
Post by: duTch on 12.08. 2018 11:11

 
Quote
.........Lightning spares (are they still around or do I remember some one taking there stuff over?)

 Fairly sure that Draganfly bought them out
Title: Re: SRM clutch
Post by: JulianS on 12.08. 2018 14:06
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.
Title: Re: SRM clutch
Post by: BrianS on 09.09. 2018 19:56
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 :-(
Title: Re: SRM clutch
Post by: JulianS on 09.09. 2018 22:40
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
Title: Re: SRM clutch
Post by: BrianS on 10.09. 2018 10:39
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 ;-)
Title: Re: SRM clutch
Post by: BrianS on 22.09. 2018 10:13
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.
Title: Re: SRM clutch
Post by: RDfella on 22.09. 2018 12:37
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.
Title: Re: SRM clutch
Post by: BrianS on 29.07. 2019 11:11
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?
Title: Re: SRM clutch
Post by: BrianS on 29.07. 2019 11:15
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*
Title: Re: SRM clutch
Post by: duTch on 29.07. 2019 13:59

 
Quote
.........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*
Title: Re: SRM clutch
Post by: RogerSB on 29.07. 2019 17:47
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.


Title: Re: SRM clutch
Post by: BrianS on 29.07. 2019 18:09
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 ;-)
Title: Re: SRM clutch
Post by: RogerSB on 29.07. 2019 19:20
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.
Title: Re: SRM clutch
Post by: RoyC on 29.07. 2019 19:24


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.
Title: Re: SRM clutch
Post by: RogerSB on 29.07. 2019 19:32

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.
Title: Re: SRM clutch
Post by: BrianS on 29.07. 2019 20:59
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."
Title: Re: SRM clutch
Post by: BrianS on 30.07. 2019 15:12
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.  ;)
Title: Re: SRM clutch
Post by: RogerSB on 30.07. 2019 16:54
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.
Title: Re: SRM clutch
Post by: BrianS on 30.07. 2019 17:36
Hi Roger. 
I may have got a later cover as I have the two-piece level plug as well ;-)
Brian
Title: Re: SRM clutch
Post by: RogerSB on 30.07. 2019 19:47
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
Title: Re: SRM clutch
Post by: duTch on 30.07. 2019 22:19

 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*