The BSA A7-A10 Forum

Technical (Descriptive Topic Titles - Stay on Topic) => Frame => Topic started by: Rich on 01.04. 2019 09:45

Title: Frame woes
Post by: Rich on 01.04. 2019 09:45
Having purchase a Gold Flash outfit, that had stood in a garage for 33 years, The plan was to tidy it up and get it back on the road. After 3 days, a carb clean, filters cleaned, new oil, petrol and the mag points cleaned it started and ran rather sweetly, the previous owner informed me that the gearbox tightened up after it got warm and suspected the final drive bearing,
So out with the gearbox, really pleased with the condition as he had already told me that in 1976 he rebuilt it with loads of new parts,however all the bearing were good except the two bushes in the fourth gear mainshaft did not have a space between them, so I machined a gap between the bushes with the gear on the lathe, should now be sorted.
Then the engine was removed, which did not take long and degreased, I masked the alloy parts up and sandblasted the rusty head and barrels, then after a good blow out with the air line, gave them a good few coats of spray heatproof matt black.
Now as the centre stand and side stand brackets had been ground off, apparently the replacement frame (RR) had been used for racing, why they took them off I don't know, the plan was to make new lugs fix them back to the frame and have it blasted and powder coated, a bit more than I wanted to do, but thought at least the frame would be good and other things can be done later keeping the bike on the road.
Well all good plans and all that, John Chaterlea25) helped me out with a drawing of the lugs but I could see that without a visual with a good frame this was going to be difficult, so a friend in Wales who has had an A10 in bits for 11 years is lending me his frame and centre stand which will make life easier, then the impossible bit, removing the swinging arm, the shaft is stuck in the S/A blocks, tried the threaded rod bit with spreading the frame a bit to try to release it and a few swipes with mighty thor against the loose nut on the shaft but to no avail. Not wanting to cut it out and have all the work removing the shaft and silent blocks plus the additional cost of parts and then having to refit them, without a press I would have to pay a machine shop, I have decided to blank of any areas I do not want grit getting into, having the frame blasted and then spray it myself with the swinging arm in situ.
Just waiting for the loaned frame to be delivered, (by another friend). Its good to have buddys.
Progress reports to follow
Title: Re: Frame woes
Post by: Greybeard on 01.04. 2019 10:03
Sorry to sound like a cracked record chaps: Do you know if the crankshaft sludge trap was cleaned during previous work?
Title: Re: Frame woes
Post by: KiwiGF on 01.04. 2019 12:57
Having purchase a Gold Flash outfit, that had stood in a garage for 33 years, The plan was to tidy it up and get it back on the road. After 3 days, a carb clean, filters cleaned, new oil, petrol and the mag points cleaned it started and ran rather sweetly, the previous owner informed me that the gearbox tightened up after it got warm and suspected the final drive bearing,
So out with the gearbox, really pleased with the condition as he had already told me that in 1976 he rebuilt it with loads of new parts,however all the bearing were good except the two bushes in the fourth gear mainshaft did not have a space between them, so I machined a gap between the bushes with the gear on the lathe, should now be sorted.
Then the engine was removed, which did not take long and degreased, I masked the alloy parts up and sandblasted the rusty head and barrels, then after a good blow out with the air line, gave them a good few coats of spray heatproof matt black.
Now as the centre stand and side stand brackets had been ground off, apparently the replacement frame (RR) had been used for racing, why they took them off I don't know, the plan was to make new lugs fix them back to the frame and have it blasted and powder coated, a bit more than I wanted to do, but thought at least the frame would be good and other things can be done later keeping the bike on the road.
Well all good plans and all that, John Chaterlea25) helped me out with a drawing of the lugs but I could see that without a visual with a good frame this was going to be difficult, so a friend in Wales who has had an A10 in bits for 11 years is lending me his frame and centre stand which will make life easier, then the impossible bit, removing the swinging arm, the shaft is stuck in the S/A blocks, tried the threaded rod bit with spreading the frame a bit to try to release it and a few swipes with mighty thor against the loose nut on the shaft but to no avail. Not wanting to cut it out and have all the work removing the shaft and silent blocks plus the additional cost of parts and then having to refit them, without a press I would have to pay a machine shop, I have decided to blank of any areas I do not want grit getting into, having the frame blasted and then spray it myself with the swinging arm in situ.
Just waiting for the loaned frame to be delivered, (by another friend). Its good to have buddys.
Progress reports to follow

You don’t need a press to remove and fit new silent blocs, just some threaded bar and spacers, and a fair bit of blood sweat and tears.

The hardest part of doing the job at the moment, I’ve read, is finding good new silent blocs.

If you’re interested in changing the blocs I can search for my post on topic for you.
Title: Re: Frame woes
Post by: bl**dydrivers on 01.04. 2019 15:36
Found this and going to do it after painting the frame.

https://www.a7a10.net/forum/index.php?topic=13733.0

https://www.a7a10.net/forum/index.php?topic=13650.0

Title: Re: Frame woes
Post by: RichardL on 01.04. 2019 17:38

... the shaft is stuck in the S/A blocks, tried the threaded rod bit with spreading the frame a bit to try to release it and a few swipes with mighty thor against the loose nut on the shaft but to no avail. Not wanting to cut it out and have all the work removing the shaft and silent blocks plus the additional cost of parts and then having to refit them, without a press I would have to pay a machine shop...

While KiwiGF's and BD's advice is good/true, the first problem is still getting the spindle free of the blocs. I'm thinking that much of the force applied by "Thor" to break the rust grip might be getting absorbed in the rubber of the blocs and in bending the frame on the left side. Since you have a lathe (or use of one), instead of using threaded rod as a spreader, why not use it as a press, using the largest diameter all-thread that will fit through the spindle (I forgot the ID figure and can't get it this moment). Then, turn a drift/mandrel with a shoulder having the same ID and OD as the spindle. For the left side, create a block that straddles the shape of the spindle flange and lands on the frame flange. Now, when the nut on the all-thread is tightened on the right, all the pressing force will go into breaking the bond between spindle and bloc. You could even employ Thor again to add a shock to the pressing force, this time without losing energy in the rubber. All this is just hypothesis, of course, because I haven't tried it.

Richard L. 
Title: Re: Frame woes
Post by: Rich on 01.04. 2019 18:54
Yes Greybeard the sludge trap was cleaned out in 1976 when it was rebuilt, it has been off the road some 33 years, I do not intend to strip the engine down just to check it as  it has not done many miles since then the trap should be fairly clear as the oil etc. has not been moving, I do intend to give it a clear out with some sort of flushing oil.
Good idea RichardL I do have a lathe and will try the pulling it out with a threaded bar method tonight. will report back when I have tried it, if it is not successful then it will stay in situ , no big deal as I was going to ride it as it was, rust and all, but decided I would like it to be a bit tidier than oily rag condition. I do not want the cost of a bush kit or even fitting bad silent blocks so if the shaft slides out it will go back in as is.
Title: Re: Frame woes
Post by: chaterlea25 on 01.04. 2019 19:52
Hi All,
Applying heavy pressure to the spindle will distort the mounting plate on the frame   *warn*
All too easy to do  *sad2*
Sacrificing the spindle does the least damage

John
Title: Re: Frame woes
Post by: RichardL on 01.04. 2019 20:04
A quick P.S., and hope I haven't said something that could ruin your day. My suggestion assumes that it is imperative to get the spindle out even if it gets damaged in the process. Seems you intend to reuse the existing spindle whose threads might be crushed, On the other hand, you are obviously machine savvy, so probably don't need the likes of this weekend mechanic with one running A10 to tell you what's up.

Richard L. 

Just saw John's post. I thought he was going to warn against damaging the spindle. Instead, he's concerned for the frame flange. I thought my concept might be OK because of the block that would straddle the spindle flange and backup the frame flange.
Title: Re: Frame woes
Post by: Rich on 01.04. 2019 21:15
well I tried the threaded rod pulling method, first I locked two nuts on the M12 threaded rod with two spanners, the next size up would not go in, I then turned the nuts down so they just past through the large spindle nut, then turned a small shoulder at the end of the turned nuts so it just fitted the id of the S/A shaft, to make sure the thread was not damaged, for the other end I had a large tube with a flat plate welded to the tube, with a hole in the centre, I offered this up to the spindle shaft lock plate and cut am inch slot out of it to clear the top part of the shaft plate, had to do that as any bigger tube would have been useless, put the rod through and tightened it up and used Thor to give the end of the rod some shock treatment, then tightened it some more and used Thor again, all to no avail.
So the swinging arm is staying put, I removed the rear shockers to see what movement I had on it, I do not know the correct movement but it is more than the shocks will move, a bit tight on the extremes, so I guess the silent blocks are working, there is no play on the S/A so let sleeping dogs lay and all that
No frame parts were hurt or bent during this episode!!
Title: Re: Frame woes
Post by: RichardL on 01.04. 2019 21:33
I'm honored that you thought enough of the idea to try it. Sorry it didn't work. Oh, the strength of 33-year-old rust!

Richard L.
Title: Re: Frame woes
Post by: Swarfcut on 01.04. 2019 22:43
Rust Indeed, the finest locking compound in the universe, and available for free.

 The design is flawed. When new, the spindle must pass (with a strong push fit) through the centre tubes of the silentblocs. When the spindle nut is tightened, the frame flanges are drawn together to clamp them and the inner tubes together, but the friction available to hold the centre tubes still is just a small circular area, namely the end section areas of the inner silentbloc tubes. More friction between the tubes and fixed spindle is desirable, but makes assembly more difficult. Fortunately surface rusting over time between the inner tubes and the spindle locks the parts together, hence the problems to dismantle. It is very unlikely the spindle will come out easily and without damage.

 If and when, sacrificing the spindle and dropping the S/A is by far the easiest way, as recommended by Chaterlea John.  Removal of the S/A from the frame allows heat, violence and every other trick you know to get the old bushes out  of the S/A without damage to the frame. Warming the rubber will melt it, best to do when there is no one around to complain, and allow the inner tubes to be drawn out. Slit the outer tubes lengthwise, then collapse them inwards.

 The existing silentblocs should be capable of supporting the unloaded S/A more or less horizontally and not be able to move through a large arc. They should return to the rest position, after deflection. If they can't or don't the rubber has failed or is no longer bonded to the inner and/or outer tubes.


 Swarfy.
Title: Re: Frame woes
Post by: Greybeard on 02.04. 2019 00:00
Please don't use flushing oil. If there is any crud in the sludge trap you do not want it loosened so it can move along and into the big end journals.

Sorry to leave the main topic Admin but I needed to respond.
Title: Re: Frame woes
Post by: RichardL on 02.04. 2019 00:46
Hmmm.

Someone else must surely have a better idea, but I see a future of cutting off the spindle flange (with cutting wheel, or something), spreading the frame so the ends of the spindle can be sawn off. Then, once the swingarm is out, burning out the rubber to remove the remains of the spindle along with the blocs' inner tubes. Then, slitting the outer tubes, as Swarfy notes. Like Rich/you said, it ain't comin' out any time soon.

Richard L.
Title: Re: Frame woes
Post by: duTch on 02.04. 2019 01:56

 Save yourself a lot of heartache and if it ain't broke don't try and fix it *bash*, spray the spindle with lanolin as best you can and ride the bike until it needs it- sounds like a winter job anyway
Title: Re: Frame woes
Post by: Rich on 05.04. 2019 19:01
I have purchased a new shaft and tried it into one of the spare swinging arms that I have and it is a nice tight fit through the bushes, one of the wheel adjuster bolts has stripped its thread in the swinging arm, so a helicoil will sort that out. so once I have made the centre stand lugs, the tank centre bolt lug and the tank side grommet lug all of which have been cut of by a previous owner that raced, the frame will be powder coated black along with all the tinware, as I intend to get rid of the Gold colour and have an all black Gold Flash. Will the swinging arm bushes stand up to the heat of powder coating?
Title: Re: Frame woes
Post by: berger on 05.04. 2019 19:36
I have not been to the pub, don't know about powder coat but mine stood stove enamel in 1981ish maybe I was lucky - like lucky lenny- there's a joke in there somewhere but its not for this channel  *eek*
Title: Re: Frame woes
Post by: Rich on 07.04. 2019 20:14
I have been busy this weekend, using a frame that was loaned to me, I have made a template for the centre stand lugs missing on the frame, just need to get them cut out from suitable thickness steel. Also missing from the frame was the front seat fixing tube and pin, the two left hand toolbox fixings, the tank centre bolt fixing, saddle and all, as well as the bracket that drops down from the top frame tube that take the tank rubbers and of course the side stand bracket. I have made the drop down top tube bracket from two pieces and drilled all the holes in them as per the original, also the tank fixing saddle just as the original, these two parts I will get welded or brazed by a professional, not sure which would be best,the front seat fixing was an easy make using the lathe to turn to the right size, drill the hole to take the pin part and drilling the hole for the locking bolt, this I also welded into position the side stand is one of the Indian universal ones which I have reworked so I can actually take the swivel bolt out (it was a rivet) to leave the brackets on the frame but take the stand part off, the top part of the bracket I have welded in place, now the stand will not move resulting in the bike falling on the ground. the two lugs for the toolbox on the left side of the frame down tube, was turned on the lathe and drilled and tapped to take the studs, then welded to the frame using the loan frame to get the exact measurement for location.
Then I ground the end of the swinging arm tube off and using the air disc cutter, (very thin cutting disc) I cut the tube between the frame and the s/a tube and removed the swinging arm, I have a new tube and a spare swinging arm to go back in.
I then pulled the squashed in plates in front of the top suspension bolts, where the oil tank and tool box bolts go through, some one had been heavy handed tightening those bolts up. using a thick flat square washer and a bolt with an inside washer, worked a treat, I wonder if a spacer would be a prudent addition for these two fixings?
I need to make some sort of location template to get these centre stand lugs in the exact position as with no stand it has to be spot on, job for Monday after the morning physio at the gym, its a bugger getting old
Title: Re: Frame woes
Post by: chaterlea25 on 07.04. 2019 21:18
Hi Rich
Good work  *smile*
I gave you the measurements of where the stand lugs sit when a straight edge is placed on top of the mudguard lug
compare that with the loaned frame

Quote
I wonder if a spacer would be a prudent addition for these two fixings

Yes there should be spacing tubes, 1" long from memory
They are shown in the parts book

John
Title: Re: Frame woes
Post by: Rex on 07.04. 2019 21:46
Not in my experience. Rubber is degraded or destroyed by the heat process.
I feel your pain with the bushes though. Last time I did this job on a BSA C12 there's not a threaded rod in this world that would pull those sods out, so cut and destroy was the only way. As noted, correct SilentBlocs aren't easy to find though.
Didn't  someone once say the best way is to re-engineer the whole shebang is by turning up replacement bushes in phos-bronze?
Title: Re: Frame woes
Post by: RichardL on 08.04. 2019 00:59
Rex,

Two things. First, the threaded rod was an attempt to free the spindle from the blocs, not the blocs from the swingarm. Didn't work anyway. Regarding custom bronze bushes, this link was posted earlier in this thread. https://www.a7a10.net/forum/index.php?topic=13733.0

Richard L.
Title: Re: Frame woes
Post by: Guy Wilson on 08.04. 2019 10:38


You don’t need a press to remove and fit new silent blocs, just some threaded bar and spacers, and a fair bit of blood sweat and tears.

The hardest part of doing the job at the moment, I’ve read, is finding good new silent blocs.

If you’re interested in changing the blocs I can search for my post on topic for you.
[/quote]

I had the same problem.. finding replacement silent bloc bushes took time. I think (and I wish I could be certain) I called Petter Hammond MC +44 1285 652468 who had a set on the shelf. This was last September..

cutting out the old bushes is the only practical way of removing them. The Threaded rod technical is the best way to refit. Its really (REALLY) important to measure the combined length of the replacement bushes against the swinging arm. The bushes are generally slightly longer and need cutting to length. Something you can't do once fitted...
Guy
Title: Re: Frame woes
Post by: Rich on 08.04. 2019 12:33
Peter Hammonds are my local shop, they do not have any in stock, Wassell are out of stock and also MCA which are British made are also out of stock, so I will use the spare swinging arm, John I am going to make a jig, some thing with a rod and spacer to go through the lugs and then bolt onto a fixed point on the frame on the loan frame, then the welder will get them in the correct position,without having to measure anything, in the process of cutting them out know, just having a lunch break :-)
Title: Re: Frame woes
Post by: berger on 08.04. 2019 12:52
REX I know what your saying re-- the bushes heat and rubber, it was so long ago in the days of dad saying go see your mates in the pub and when you get back job will be done and done right. he might have got them out before myself and a mate took mine and his notrun frames etc to Long Eaton enamelers  or in the good old days of customer service they took them out and put them back in *dunno* all I know is I didn't take them out or put them back in, only ones I took out were on a cubby for dad to make new bushes and pin---- or they withstood the process at the paint shop *dunno*
Title: Re: Frame woes
Post by: Guy Wilson on 08.04. 2019 15:03
this is something I found useful..
Guy
Title: Re: Frame woes
Post by: Swarfcut on 08.04. 2019 18:28
Extremely useful if I may say so.      Will save lots of frustration and anguish, as once in, destroy to remove.     BIG THANKS!!!

 Swarfy
Title: Re: Frame woes
Post by: KiwiGF on 08.04. 2019 21:38
Extremely useful if I may say so.      Will save lots of frustration and anguish, as once in, destroy to remove.     BIG THANKS!!!

 Swarfy

A post on the topic (there are many), but you’re going the bronze bush route?

https://www.a7a10.net/forum/index.php?topic=4293.msg63859#msg63859
Title: Re: Frame woes
Post by: Rich on 14.04. 2019 08:43
I decided to try and remove the swinging arm bushes as I have a spare swinging arm if it fails, be it with a wheel adjuster thread stripped, which will be an easy repair, anyway I used a blow torch to get the swinging arm hot and destroy the rubber and drifted the whole lot out, but how does one get the outer bearing sleeves out?
Title: Re: Frame woes
Post by: Swarfcut on 14.04. 2019 09:48
Rich. Go back to my earlier post, April 1. Cut a slit lengthways in the outer tubes, not deep enough to cut completely through, thus avoiding damage to the S/A, but enough to weaken them  so they can be collapsed inwards with a pointed drift between the tube outer and the S/A.
 Get the S/A blasted and powder coated before fitting new bushes, if you go the rubber route, to avoid heat damage to new bushes. For installation, check dimensions first as above, then the long threaded rod stud and spacer trick avoids violence.  Make sure there are no burrs to impede easy entry.
 Bronze bush conversion, final finish can be left 'til last.

 Swarfy.
Title: Re: Frame woes
Post by: Rich on 14.04. 2019 18:23
Done bush sleeves out and the swinging arm through hole is blanked off ready to be blasted,workshop clean out as that molten rubber got every where, motor on the bench as I have been nagged by others to clean out the sludge trap, am I going to open a can of worms, I hope not
 
Title: Re: Frame woes
Post by: Greybeard on 14.04. 2019 18:53
... have been nagged by others to clean out the sludge trap...
Good lad! Just ask questions.