I'm working on a '72 Rupp Enduro, and the holes in the frame where the swingarm bolt goes are slightly egg-shaped, letting the swingarm move from side-to-side. I see that the swingarm bushings have a jagged edge that I assume is to bite into the inner edge of the frame and help keep the swingarm located? If I install new bushings and tighten the crap out of the bolt will it stay put, or do I need to do more? I thought about welding up the holes and re-drilling them, but I'm not sure how I'd get them located properly. I'm guessing this is quite critical to maintain the correct wheel alignment. This is my first mini bike project and I'm hoping you can help me out. I'm a Rupp newbie, but I'm already having fun with the project! Thanks for your help!
'72 Rupp with sloppy swingarm - how to fix?
I just welded mine up and re-drilled it. It worked like a charm. Had to do the same thing with the kickstand holes and hooks.
You may want to check the kickstand area out real well while you have it apart, chances are it will need some attention as-well.
When you reassemble it, leave everything clean and dry and use a new grade 8 bolt and tighten the hell out of it. The only movement comes from the flexing of the bushing.
You may want to check the kickstand area out real well while you have it apart, chances are it will need some attention as-well.
When you reassemble it, leave everything clean and dry and use a new grade 8 bolt and tighten the hell out of it. The only movement comes from the flexing of the bushing.
I thought of that idea after I posted my message. I'm thinking I can install new bushings in the swingarm, make a couple of washers from round stock with the right size hole (3/8"?), put the whole thing back together with the washers outside of the frame, line up the swingarm with the frame (probably use a straight edge along the sides of the swingarm and measure to the motor mount), then weld the washers in place. It won't have a "factory original" look, but it will make it ridable again.
Egged out holes are usually worn mosty on one side. I have used a mig welder and given the worn side a few zots to build it up. Then I used a rat tail file to resize the hole to fit a new bolt. The sides of the hole can be brought back flat with a 4" grinder or flat file. This way the bushing should have the full hole diamiter to bite into.
Is it this style of a Rupp swing arm?
I'm planning to buy 2 replacement plates (back ordered at Rupp.com) to dbl. up the swing arm pivot point and jack shaft as this could see some serious off roading and racing...
IMO the swing arm does not pivot on the inner round bushing but the bolts threads lock against the round bushing on the ends and bolt smooth round to frame plate is the rotation bushing.
With my dbl upped plates...I can make a bronze bushing for there too... :thumbsup:
I'm planning to buy 2 replacement plates (back ordered at Rupp.com) to dbl. up the swing arm pivot point and jack shaft as this could see some serious off roading and racing...
IMO the swing arm does not pivot on the inner round bushing but the bolts threads lock against the round bushing on the ends and bolt smooth round to frame plate is the rotation bushing.
With my dbl upped plates...I can make a bronze bushing for there too... :thumbsup:
If you have a 1970 and up Rupp you can put a 3/8 ID x 1/2 OD flange bushing into both sides of swing arm bolt holes on the frame, Drill holes to fit 1/2 bushing. Flange goes on the outside of the frame, Trim them to be flush with the steel on the inside where the swing arm goes, Not factory, but when slop develops again, you just need to replace the bushings before they dig in to the steel again.
