I put new wheels on my bike today (along with new cassette, RD, and STI levers), and I'm noticing that the cassette sort of wobbles as the rear wheel spins while on the stand. I've seen this in other peoples' somewhat aged bikes, but these wheels are brand new (though admittedly factory-built Shimano 105 wheels - nothing grand).

I assume the freewheel body isn't on straight or something like that... (?)

Any ideas on how rectify this? Does it matter at all? (It doesn't seem to affect shifting at all, but it must introduce drag in the system...)

I don't know why it's happening, but I know what you're talking about because my new wheel does the same thing. Of course it's a cheapo 55$ REI wheel with a cheapo $20 Nashbar cassette. It seems to run down the road just fine, so I'm not really worried about it.

DanO

I've assumed it's caused by the freewheel not being on exactly the same axis as the wheel hub/axle/skewer (not sure which one).

Not sure what do to about it or even if there's any point in doing anything.

That is exactly the answer I got at some repair seminar back in the 80s at one of the bike shows. A slight misalignment due to manufacturing inconsistencies is the exact wording I think. This pops up all the time. High end, low end, doesn't seem to matter. Bottom line is as long as the function is not affected, live with it.

The original poster and some of the people who replied are talking of two different things.

Freewheels were screwed upon the right side of the hub, and quite frequently the threading was a bit squewed, making for a very wobbly freewheel.

Cassettes, on the other hand, are inserted in a spline and should be almost straight. I said "almost" because it's not micrometric precision. But a few factors may make it crooked:
– sand on the freehub (i.e. the base onto which the cassette is inserted), which would prevent it from sitting squarely;
– not installing the last cog in its proper spline (i.e. small notch vis-à-vis small ridge), which means the lock ring isn't seated properly on all sides.

Both problems ultimately mean that the cassette is not properly seated and may be a wee bit loose. It will then loosen itself, especially if you ride on cobblestones. And then you'll have problems.

So in a nutshell, a slightly wobbling cassette is not a problem, but a loose one is.



P.S. The move from freewheel to cassette was done around 1987-1995, depending on the value of the bike (i.e. more upscale bikes moved sooner)

Freewheels and freehubs have a bit of play in them for the bearings to float over the pawls. If it doesn't, then you don't have any freewheel action.

That's what it is. There is no point in worrying about. The chain has more than enough play to compensate.

The wobble can happen to both.

I had a similar problem with some used wheels I bought on eBay. They have Ultegra hubs. When I bought them the freehub was seized, and with a lot of soaking and degreasing I got it loose, but the freehub was very loose on its bearings and 'wobbled' a lot, causing the cassette (which was brand new) to do likewise. Solution - I bought and installed a new freehub on Friday and now everything is as tight as a duck's ass. Mine was due to worn bearings in the freehub, but it sounds like your's shouldn't be as the wheels are brand new.