alignment issue?

[Kassassin]

I hit a construction hazard bending both my rims. Got the bike fixed(and inspected by a dealer) and it feels like at speed(50+mph) the handle bars seems to turn back and forth ever so slightly. Maybe a couple millimeters. I have been off the bike for a while waiting for insurance and such to fix it, but I cannot tell if this is simply new tires(pilot powers) being aggressive and not holding a line as well, or some kind of alignment issue.

Anyone know symptoms of this feeling?

 

[Dennis in NH]

I say ride it some more and get the tires warm (my theory is flat spots?) and then see how things go. Be careful about getting up to speed because if those little millimeter wobbles turn into big wobbles and tank slappers , you will be screwed.

Even before going out again, see if you can check the chain/wheel alignment. I have a chain alignment tool for this or you can use the "string" method -- I prefer the tool.

Check the steering head bearings and ensure there's no play in the steering head.

Good luck and be careful -- you're now playing test pilot here.

Better yet, if possible, get some bike mechanic to take a look at it.

Dennis

 

[TownsendsFJR1300]

If the hit was bad enough to bend the rims, I'd be concerned about the tires themselves. They also would have had to give to give a bunch to get to the rims.

And yes, check the steering head bearings not only for tightness but for smoothness/binding....

BTW, My old Goldwing (04) developed a de-cel wobble in the handle bars at 35-45 mph . New tappered steering head bearings solved the problem.


Good luck..

 

[deeptekkie]

It sounds to me like it could be some "slop" somewhere in the system and it sets up harmonics, (or a gyro effect), at different speeds. What everyone has said here is all possibilities. It just have some free-play somewhere, maybe on both ends of the bike? Good luck!

 

[RJ2112]

This would be a good time to 'true' the fork. A hit hard enough to damage both of the rims means you whacked the whole bike, whether it shows or not. If you are only talking about a couple of mm motion in a cyclic manner, I'm betting on the difference in tread pattern in the front tire, rather than actual physical damage. But it doesn't hurt to make sure.

It's unlikely in my view that the swing arm would be affected as much as the fork. The fork legs are only held in place by clamping force at the upper and lower triple clamps. Between those two points, the fender mounts, and the front axle, the tubes are supposed to stay parallel. This is a relatively beefy fork, compared to the last one I tweaked out of true.... but the process is quick, and relatively painless:

1) loosen the bolts on the upper triple clamp that hold the fork tubes. DO NOT loosen the lower triple clamp bolts.(finger tight)
2) loosen the fender mounts(finger tight)
3)loosen the front axle. (finger tight)
4) mount the bike, grab the front brake hard, and romp on the handle bars. Get the suspension to move through as much of the stroke as you can, and ensure that you do so half a dozen times or more.
5) when you are done, tighten everything up that you loosened. You're done. Ride it and see if it made a difference.

By forcing the suspension through it's full stroke, with a 'common' reference, you will ensure that the tubes align themselves to their straightest path. Straight means less stiction (better action) and less off set from straight ahead.