C15T Frame And Swinging Arm Alignment

[japes1275]

Hello, my first post on here but been lurking around the forum for a while.

I'm in the middle of restoring my 1962 C15T and have come across a bit of a problem. The rear wheel is quite a bit out of line with the main frame loop and after a lot of checking and measuring it seems to be that the whole swinging arm is out of line. The lug that the swinging arm spindle goes through is twisted over to the left of the bike compared with the bottom frame tube. I've found a thread on here with someone with a similar problem, in fact it looks exactly the same in the photo. Here is a link to it:

http://www.trialscentral.com/forums/topic/27793-c15-frame-alignment/

All the brazing seems sound and it looks to that it was made like that, maybe BSA's way of getting chain clearance for the wider trials tyre than on a standard bike. Can anyone confirm if that is the case?

The rear subframe obviously is also out of line but when the bike is all built up it looks fine as the wheel sits equally between the shocks etc.

I've owned and used the bike for 25 years and although I knew the rear wheel was a bit out of line it's always been ok. It's not road registered so getting it through the mot was never a problem. I'm now thinking of getting it registered so would now need to get it mot'd which might be a problem if the wheels are out of line.

So my options are:

Leave it as is and see if it passes an mot, if not I'll just not bother registering it and keep using it as it is - it rides fine.

Use spacers at the rear wheel to try and get it closer to line up. This would mean the wheel was then out of line with the subframe though.

Get the frame lug moved in line by re brazing it. Not something I could do myself and I'm not even sure it should be done!

Any thoughts would be greatly appreciated!!

Cheers

[mcman56]

I posted that original picture. This was a street bike so I assume it twisted during some sort of crash. When I assembled the bike with a 428 heavy duty chain, the chain was touching the inner primary cover. I needed to do something and was able to bend it back.

I had a steel motorcycle carrier that fit into a 2" trailer hitch. A bike would ride in a long piece of steel channel about 5" wide across the back of the vehicle. It was a bolt together so that I could assemble it with the flat side of the channel facing up. I welded tabs on the flat side that would mate to the footpeg mounts and lower motor mounts on the frame. With the hitch slid into the carrier on the truck and the frame bolted in place, it was pretty securely mounted. I then made a pin that was a close fit in the swingarm pivot and put it in the end of a long piece of 1 1/2" pipe, maybe 8 feet long. This became the lever arm to twist it back. I had to use heat from a propane torch to get it to move but was able to move it into visual alignment. I did get hear one "tink" in the process but could not find a crack or any other defect so am not sure exactly what moved. I made a close inspection after riding in multiple rocky trials and it continued to look good.

When placed on a flat surface, I could see that the swingarm was also bent. It was pretty easy to straighten so I don't remember the details. I think I mounted in a vise and used a lever or maybe hammer.

I found a picture.

Edited December 15, 2013 by mcman56

[b40rt]

1 use a standard 428 chain

2 use the snail cams to compensate

3 go to a "sympathetic" MOT station

4 for chain to tyre clearance, dish the wheel

5 ride and enjoy

Edited December 15, 2013 by b40rt

[japes1275]

Thanks chaps, I'm erring on the side of leave as is at the moment. I'm just not sure enough that its not supposed to be like that to start altering it. I know I can get the desired clearance as its been ok for years.

Interested to hear any more suggestions or advice!