Bicycle Mechanics - Freewheel Wobble

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bagster
02-29-08, 02:56 PM
The LBS just shippped a new rear wheel and Shimano Mf Hg37 7-speed freewheel for my '87 Gt mt. bike.
I noticed the freewheel wiggles back and forth visibly while spinning the wheel.
Is this normal? If not, how do I tighten it? I have a grating sound coming from the drive train while
riding and am wondering if this could be it.

waldowales
02-29-08, 05:04 PM
It is not unusual for a freewheel to wobble. Doesn't hurt anything.
operator
02-29-08, 06:03 PM
Normal. Assuming it's not actually crossthreaded.

markjenn
02-29-08, 10:27 PM
I understood that a small wobble was designed into some freehubs for better shifting.

- Mark
DieselDan
03-01-08, 06:44 AM
I understood that a small wobble was designed into some freehubs for better shifting.

- Mark

Without the wobble, it won't freewheel(verb).
twobikes
03-01-08, 07:41 AM
If it is new, there is no problem. If it has some miles on it, a wobble combined with a clunk might mean the retaining ring is threading itself out and you have play in the bearings. I had this happen a couple of times on one freewheel. Twice it lost its bearing balls and left me stranded. Most freewheels do not have retaining rings that thread themselves out, but it can happen.
WillisB
03-01-08, 05:13 PM
Mine wobble. It's normal!
jfmckenna
03-01-08, 05:23 PM
I understood that a small wobble was designed into some freehubs for better shifting.

- Mark

I've heard this too and wonder if anyone can confirm it.
operator
03-01-08, 05:41 PM
I've heard this too and wonder if anyone can confirm it.

Sounds pretty/extremely bogus to me.
Rowan
03-01-08, 11:30 PM
I believe that the wobble comes from the wider tolerances in fit between the ball bearings and the races inside the freewheel. If you disassemble a freewheel, you will find some spacers under the lock ring. These vary in thickness from freewheel to freewheel because of those wide tolerances, and are intended to take up the bearing preload. However, there will continue to be movement or wobble as described as the wheel rotates because in the production line process, it's unlikely that the exact combination of spacers will be fitted. You've got to remember that these days, freewheels are near the bottom of the retail pond... as borne out by their cheap price... and hence fine tolerances aren't a major concern.

You can believe the shifting theory if you wish. I don't think it's correct.

The wobble is nothing to worry about, and is mentioned frequently on this forum by people relatively new to bicycle mechanics.