Wheel bearing problems
I've got a long-standing problem with the bearings in two back wheels - an old Corima Aero and a Zipp 808. The bearings in both needed replacing, so I carefully disassembled the hubs and measured the old bearings and examined them for model numbers. Both took proprietary-sized bearings, so rather than paying the pi$$ take prices for genuine parts, I bought bearings to the same spec off ebay. I then reassembled both units exactly as they were originally (confirmed by referring to online exploded-view diagrams) and, not owning a bearing press, I pressed them home using variants on the "QR skewer and various-sized 1/4" sockets theme. In both cases, there is a sleeve that fits between the inner faces of the bearings, providing a guide as to when they are pushed fully home and, in both cases, this sleeve is held securely in place, but not impinged on by the bearings. (Worth pointing out here that I have used exactly the same process on several other wheels, with no problems.)
However, when I come to tighten everything up (there is no pre-load adjustment on the lock nuts - you simply tighten them against each other to a certain torque), the bearings bind. In the case of the Corima, anything more than finger tight and the wheel won't even spin (!) and in the case of the Zipp, I can just about find a pretty unsatisfactory compromise where there the nuts are slightly tighter than finger-tight and the wheel just about spins. Ive had the whole lot apart and together again more times than I care to remember and it's doing my head in.
I'm midway through a protracted email correspondence with Corima in France, which doesn't look very positive, and Zipp USA suggested adding an extra 0.25mm washer into the system. I haven't yet tried this latter solution, mainly because I would have thought adding extra width to the structure between the lock nuts would make it even quicker/easier to over-tighten them.
Does anyone have any suggestions? Thanks in advance.
However, when I come to tighten everything up (there is no pre-load adjustment on the lock nuts - you simply tighten them against each other to a certain torque), the bearings bind. In the case of the Corima, anything more than finger tight and the wheel won't even spin (!) and in the case of the Zipp, I can just about find a pretty unsatisfactory compromise where there the nuts are slightly tighter than finger-tight and the wheel just about spins. Ive had the whole lot apart and together again more times than I care to remember and it's doing my head in.
I'm midway through a protracted email correspondence with Corima in France, which doesn't look very positive, and Zipp USA suggested adding an extra 0.25mm washer into the system. I haven't yet tried this latter solution, mainly because I would have thought adding extra width to the structure between the lock nuts would make it even quicker/easier to over-tighten them.
Does anyone have any suggestions? Thanks in advance.
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Comments
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Don't know about Corima, but a similar problem occurred to a front Zipp hub (a track hub) I have seen recently. Nobody seem to be able to sort out this hub (condor cycles had a go too), so that it actually spins with the nuts tight. It is a case of bad design of the bearing lodging and it seems to be a recurrent problem with Zipp hubs, in one way or another.
Maybe it's time for them to abandon the fancy idea of using their own hubs and use something more reliable made by others, being that Dt Swiss, Chris King or else.
Can you contact the SRAM service centre in the UK, who apparently deals with Zipp issues too?left the forum March 20230 -
glanders wrote:I bought bearings to the same spec off ebay.
THIS
Are you 100% sure the bearing is exactly the same dimensions, it may look the same but a lot of ebay sellers source cheap parts in far off lands where QC is far from desirable.glanders wrote:...and, not owning a bearing press, I pressed them home using variants on the "QR skewer and various-sized 1/4" sockets theme.
THIS
Did you press the bearing in by applying pressure to the inner race sleeve?0 -
Thanks folks. It's interesting to hear that other people have had similar problems with zipp hubs. It's a pretty old wheel (2007?) so I'm not sure the uk distributors will be that interested? Definitely worth a go though. And re the other points - my trusty lidl digital verniers suggest the old and new bearings are identical - might be a couple of thou out either way, but not enough to cause the problem. And I chose sockets that just about fit inside the bearing shell, so any pressure should have been on the outer race.0
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With the wheel off the bike, do the bearings move freely?
If not, then the spacer 'sleeve' is too long for the new bearings, OR the outer race of the new bearings is pressed too deep into the hub (maybe the width of the outer race is less than OEM bearings.
If the bearing DO spin off the bike, then the compression of the QR is causing the inner races to go out of alignment - probably by moving the inner races inward slightly, or causing them to tilt.
Jay Kosta
Endwell NY USA0 -
Some Ebay unbranded bearings are terrible quality. I've bought some in the past that literally crumbled. SKF / FAG or similar quality from Ebay would be fine. SKF C3 (larger C number greater clearance) have a slightly larger internal clearance therefore are less likely to bind.
It also sounds to me like the inner sleeve is slightly too short for the bearings you're using. This would certainly make the bearings seize once tightened. Perhaps a shim washer would cure the problem.
Good luck0
