Originally Posted by timcupery
My sense is that the bolt-ons needn't go as tight as a typical QR. They are convenient to have for commuting when you don't want to worry about locking up your wheel.
But really, how much difference does a tight QR make in bearing adjustment? I've never heard of that issue before. Seems to me that if your cons are adjusted well and the nuts that border the cones are tightened against the cones, you've taken any play out of the threads and tightening the QR won't make any difference. Though I'd be happy to be shown wrong on this (and will have to start thinking more about how I adjust hubs when I overhaul them).
lawkd, I think that you're wrong about a hollow axle flexing when a QR is tightened. A hollow axle may flex a bit more (but hardly, since the middle portion of a rod plays a very small role in its flexibility), but it's not going to stretch or compress along its length.
No, it really does make an important difference. If you have no play before tightening a hollow axle, then your hubs are overtightened when you clamp the quick release or tighten down the skewer nuts by whatever means. Here is the passage from the Park Tools site, and the link to get you there:
[begin quote]
Hub Adjustment
Quick release hubs have hollow axles that flex slightly when the quick release is closed. Hub bearing adjustments must account for this extra pressure. When a quick release hub is not clamped tight in the frame, there should be a slight amount of play in the axle. This play disappears when the hub and wheel are clamped in the frame.
To test if a hub in your bike has an adequate adjustment, grab the wheel while it is still in the frame and pull it side to side laterally. Turn wheel and test again, feeling for a knocking sensation. If no play is felt, remove the wheel. Grab the axle (not the skewer) and rock it up and down to check for play. If the axle has play when the wheel is outside the bike, but no play inside the bike, the adjustment is adequate. If there is no play in the axle when the wheel is outside the bike, the adjustment is too tight, even if the axle seems to turn smoothly when out of the bike. [end quote]
http://www.parktool.com/repair/readhowto.asp?id=105