Widening swing arm pivot point?

[joestella28]

Hi all,

I'm looking to put in a GSX1100 (GS1100 in the US I think) swing arm in to my tracker project. Like most swing arms, it's too wide. I'll only be able to narrow the swing arm so much and from what I have read on the swap, around 5mm needs to be taken off both the bosses on the inside of the frame,

My question is, how do you keep the face square? Being on the inside of the frame, it's not like you can pop it in a mill? I did wonder if you could finish the job with a facing tool as used on bicycle bottom bracket shells (i.e. http://bicyclepatents.com/facing-bottom-bracket-shells-on-the-catrike/1277/ ) but wonder if it would be man enough (even just to square it up).

If anyone has done this, I'd be keen to know how you went about it?

Many Thanks,

Joe

 

[TwoManyXS1Bs]

Joe, I think you're cruising into uncharted territory. The closest discussion, involving facing reamers, I can recall is in this thread:

http://www.xs650.com/threads/swingarm-bushings.44458/

You *might* be able to gain a couple mm extra clearance by jacking the frame more open, like with long allthread, and welding in crosspiece/stiffeners like this:

But, once you do that, fitment of swingarm to frame would need to be precise, since you could no longer expect the frame to flex enuff to close any gaps when you cinch down on the swingarm bolt...

 

[member3480]

I done many and there is no easy fix. You either have to ground down on the frame or you have to remove the bearings and sleave in swingarm and cut it.
I have done GSXR/GPZ/CBR