5twins,
Thanks so much for your comment regarding POs replacing the rear wheel bearings and throwing out bushing #20 (130mm "bolt", part #90101-06291-00) with the old bearings. My '77 has a slight hop when starting out, kinda like a dog running a little sideways down the road. Fun, but not necessarily good. Came across your response to someone else's question, and sure enough, when I pulled the wheel, the bearings were the sealed type and the bushing was missing.
For the general populace: I don't feel comfortable enough to simply replace the sprocket bearing with a smaller diameter inner race as the bearing will take too much side loading on tightening the axle nut. I don't imagine anyone who has this part will "part" with it, so is the best bet just to find a used wheel? The alternatives are to pay to machine a new bushing (probably cheaper in the long run...is anyone replacing bearings who can provide the dimensions?), machine a longer center spacer (#7 in the parts fiche), or find a wider bearing. Sincere thanks for any help!
For anyone else out there with a similar wobble problem... with the rear wheel off the ground, do the swing arm bushing play test, then try to push and pull the wheel at the top and bottom while facing the sprocket (because of chain tension, you probably won't get any horizontal, left/right push/pull movement).
If there's any significant play at all, it will normally be due to bad bearings and/or the above-noted bushing is MIA. If there is no play while rocking the wheel from the brake side, it's probably the bushing. In either case, the wheel has to come off. In either case, the sprocket side bearing has to come out, so you'll need one of those.
Thanks so much for your comment regarding POs replacing the rear wheel bearings and throwing out bushing #20 (130mm "bolt", part #90101-06291-00) with the old bearings. My '77 has a slight hop when starting out, kinda like a dog running a little sideways down the road. Fun, but not necessarily good. Came across your response to someone else's question, and sure enough, when I pulled the wheel, the bearings were the sealed type and the bushing was missing.
For the general populace: I don't feel comfortable enough to simply replace the sprocket bearing with a smaller diameter inner race as the bearing will take too much side loading on tightening the axle nut. I don't imagine anyone who has this part will "part" with it, so is the best bet just to find a used wheel? The alternatives are to pay to machine a new bushing (probably cheaper in the long run...is anyone replacing bearings who can provide the dimensions?), machine a longer center spacer (#7 in the parts fiche), or find a wider bearing. Sincere thanks for any help!
For anyone else out there with a similar wobble problem... with the rear wheel off the ground, do the swing arm bushing play test, then try to push and pull the wheel at the top and bottom while facing the sprocket (because of chain tension, you probably won't get any horizontal, left/right push/pull movement).
If there's any significant play at all, it will normally be due to bad bearings and/or the above-noted bushing is MIA. If there is no play while rocking the wheel from the brake side, it's probably the bushing. In either case, the wheel has to come off. In either case, the sprocket side bearing has to come out, so you'll need one of those.
