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Cassette wobble

aicabsolut2010-04-28 22:42:53 +0000 #1
(aka freehub wobble) How much is too much?

I remember having some slight wobble with the old cassette, and I just got a new one put on today with a new chain. I put the bike on the stand when I got home to check the derailleur tune, and I noticed that with the new equipment, shifting hadn't really improved (I had something obscene like 6500 miles on the old stuff--ooops, and shifting had recently gone from bad to worse). It was a bit better, but I still got a lot of hesitation shifting to larger cogs around the middle of the cassette, especially in the big ring. Tightening the cable didn't seem to do anything, and pretty soon I'd run into cable-too-tight symptoms. I noticed that there was a lot of space between the RD and the cassette in the big cog, so I fiddled with the B screw for the first time in 2 years. That helped the most. Shifting had only started going south in late Feb/early March, when the equipment was on another frame (so that eliminates derailleur hanger issues, which really can't be the case with both frames--and they look straight anyway). I started getting the chain checked then, and it has gotten the OK from the shops until late June when I got a "replace soon" message from them...and then I wound up taking a lot longer than I the point where I had to make a cassette purchase as well.

Anyway,... it's still not great, and I haven't tested it under load yet. I was just wondering how much the cassette wobble could be causing my problems, if at all? Also, this cassette is a lot noisier when it freewheels, which shouldn't be right, because they shouldn't have changed my freehub, right? There's a bit of a metallic sound to it too when pedaling, but that improved when I got somewhere with the shifting problem, and that might also be the sound of the hollow plates and pins of the new superlight chain.

I took the wheel off and tried to see if there was any play in the cassette, and it seems to be tightened down on there properly. The wobble is also only apparent when freewheeling, just to be clear. I've read that a 1-2mm wobble is "acceptable," but I've never seen anyone else's wobble (I've played with tuning my BF's bike with at least 3 wheelsets--yes I tune his bike ). I also feel like it wobbles more than before (which the shop said not to worry about about a 1.5 yrs ago).

I DO want new wheels, but I can't get them anytime soon, and I want these for training wheels anyway. They are cheap Shimano wheels (with supposedly sturdy Shimano hubs), and it's not really worth it to shell out $ for any new hub/freehub if I don't have to....

g192010-04-28 22:53:38 +0000 #2
From what i read on several forums is that 'cheap' cassettes are known to wobble a bit.

So it is not a big issue regarding parts not working properly.

It's lets say not perfect
aicabsolut2010-04-28 23:30:26 +0000 #3
Is Ultegra "cheap" enough to wobble? It seems like it's in the freehub on the wheel, not in the cassette itself. The wheels are Ultegra level as well. So yeah, not great, but I've seen tons of other wheels with no wobble nice or not.
ridebikeme2010-04-28 23:27:28 +0000 #4
Is it the freehub that has movement in it? Have you been able to check that??
aicabsolut2010-04-29 00:35:21 +0000 #5
I don't really know how to check it necessarily, but it has to be the freehub. It only happens when the wheel spins as if I'm coasting. When I pedal (cassette rotating), it looks totally normal. Stop pedaling, and I can watch the cassette undulate (looking at the biggest cog). It's sort of like watching an untrue wheel from the top. Only the wheel is true, so the only wobbling is at the cassette when it's still and the wheel is spinning.

I emailed a friend at the shop about it, thinking it might be an installation error or something. However, I can't detect any looseness in the cassette itself. It seems firmly and properly attached to the hub. So, I don't think the cassette is loose or busted (it performs well and it's new). It's just an unsettling thing to look at, and it seems to have gotten worse with this new cassette from the old 105 one.

I've at least seemed to fix the shifting problems, but I still don't like the looks of the wobble. I want new wheels anyway, but I want to keep these as my bombproof training set. I won't have $ for new wheels anytime soon either.
ridebikeme2010-04-29 00:19:20 +0000 #6
It may be something as easy as tightening your freehub... have your LBS check it. It's a quick fix, and if that isn't it, then I would replace it... it' isn't a very big expense.(providing of course it can be replaced). Remind me again, what type of wheel/freehub is it?



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