Vibrating Pan

[Kryzstov]

Suddenly my rigid 55 Pan is vibrating at high rpms. (It happens with the bike sitting also). It’s so strange because it just started doing it and I haven’t changed anything on the bike. It’s felt mostly in the back of the bike because my sissy bar starts vibrating violently. I’ve check the motor mounts and as many other bolts I could think of, but can’t figure it out. Any advice is greatly appreciated.

[Dragstews]

Flywheels shifted ... ??

[JBinNC]

Look at the top motor mount. The frame bolt can loosen, and the mount itself will crack through. Sometimes a visual inspection won't reveal either problem. Check your frame for cracks, too, especially at either end of the seat post tube.

Jim

[Kryzstov]

Dragstews, Omg I never heard of that happening. How would I check that?

[Kryzstov]

Look at the top motor mount. The frame bolt can loosen, and the mount itself will crack through. Sometimes a visual inspection won't reveal either problem. Check your frame for cracks, too, especially at either end of the seat post tube.

Jim

Thanks Jim. I’ll take a closer look. I’m nervous the vibration will just create even more problems if I don’t find the issue.

[Hubbard]

yank the cam cover and put an indicator on the end of the pinion shaft, turn the motor over and report back

[rockman96]

I doubt the wheels shifted unless you were hotrodding, dropping the clutch, etc. in which case the right wheel is trying to accelerate while the left wheel in effect has the binders on. My money is on the top motor mount loosening up... that will make you feel like you're riding a jackhammer. Could also be a cracked frame, but you never said how it came on other than "just started doing it".

In reality it could be any of the options that have been mentioned by the others. When it started did it come on hard like flipping a switch, or was it more gradual, and what were the circumstances?

[Kryzstov]

yank the cam cover and put an indicator on the end of the pinion shaft, turn the motor over and report back

Ok thanks. I appreciate it

[Kryzstov]

When it started did it come on hard like flipping a switch, or was it more gradual, and what were the circumstances?

It started suddenly.
And definitely no hot rodding. I don’t ride her too hard

[Hubbard]

I put a cheapassed haybailin chain on mine once and it liked to totaled my scooter. broke the top motor mount and 2 rear wheel spokes.fixed all that, put on a real chain and no more trouble.