me have long head tube
Join Date: Oct 2005
Location: Chapel Hill, NC
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freehub body not aligned correctly to hub - how much of a problem?
I've got a used Shimano 105SC rear hub with 8-speed freehub body, Uniglide- and Hyperglide-compatible (threaded on the outside and inside of freehub). Takes 9- and 10-speed cassettes too, of course. It had about 8,000 miles on it when the rim cracked, and I just built a new wheel with it. The bearings had been adjusted too tightly (so, it was properly tight when the Q/R was not tightened, got too tight when Q/R was tightened) and I had to replace one of the bearing cones. But the hub is in good shape, and just built it into a nice wheel to work with an 8-speed cassette and down-tube shifters that I had sitting around.
Now, with the bike in the stand, when I spin the wheel forward (so the freehub is clicking), I can notice the cassette weaving slightly side-to-side and up-and-down. Slightly. Probably 0.5mm to 1mm side to side, about the same up-and-down, when looking at the largest (23t) cog. What this means is that the freehub body is not in perfect alignment with the main hub body - it either screws in on a very slight angle, or it has gotten bent. My money is on the first explanation - just a slight manufacturing imperfection.
I've got a recent Ultegra rear hub on my good road bike now, and its freehub is in perfect alignment with the hub, judged this same way.
I've noticed this sort of thing with freewheels before, but there it doesn't indicate any real problem; it just means taht the freewheel threads on the hub aren't perfectly aligned, and so the freewheel is very slightly misaligned, but not enough to cause shifting problems.
On a freehub, since the drive-side bearing races on which the hub spins are in the freehub, it means that the drive-side bearing race isn't perfectly aligned with the non-drive-side bearing race. This may have been part of the problem with the cone wearing out after 8,000 miles, too.
I don't think it's a big problem, but wanted to fish around and see what people around here think. Have you seen this sort of thing before? How common is it? Does it generally point toward bearings wearing out? (The bearing races themselves seemed just fine when I overhauled the hub last summer.)