sweeks

See Park Tools and Sheldon Brown for more on this.
Sheldon is correct about the axle compressing slightly; Park is incorrect about the axle flexing, but both are correct that bearings of hubs with Quick-Release axles must be left slightly loose when the wheel is off the bike. An easy way to adjust the bearings correctly, with the axle under compression, is to use an axle vise like THIS ONE.

hevysrf

Not sold on it, a lifetime of ruining perfectly good parts by over torquing says the small diameter threads on the skewer will fail before compressing the the axle . Perhaps possible with the best quality skewer and the worst axle.

maddog34

Gladly.. Steel is Compressible... especially a hollow tube of steel. If you can't imagine this then test it for yourself.. take a bare QR hub, set the bearings to "no slop but spins free".. then mount it in a frame or fork..now feel the roughness when you rotate the previously smooth turning hub. the Hollow Axle has COMPRESSED slightly. a tiny bit of shifting of the cones/nuts on the threads may also occur.. This effect has been discussed and agreed to many times on these forums.

hevysrf

Steel is also elastic, the skewer will stretch or the small diameter threads will fail before the greater mass of the axle compresses.
My set up has a Allen head on the skewer instead of a cam, I am unable to produce bearing drag.

sweeks

Exactly. Within its elastic limit, steel experiences dimensional change in either direction according to whether the force acting on it is tensile or compressive. Since the cross-sectional area of the hollow axle is greater than that of the skewer, it compresses less than the skewer stretches... but it *does* compress.
Your axle-fixing hardware apparently doesn't put enough compressive load on the axle to change the bearing adjustment, but it's easy to demonstrate on a standard QR axle.

hevysrf

Again, I can't believe that a 5mm Allen bit on a 3/8 ratchet provides less torque and clamping force than a cam. I also maintain my sons bike, standard QR on both front and rear, just haven't run across the this before, learn something new every day.

Been working on my front disc brake, Shimano hydraulic, 500 series, new lever, new caliper, new hose, freshly bled. Can you tell me how to keep clearance pad to rotor, I can't seem to stop pads from contacting rotor. The old SRAM assembly never had clearance either unless I removed some material from the pad.

Kontact

Is the hub in your picture looseball? Cartridge bearing hubs are not affected by skewer tension.

hevysrf

Yes, it is cartridge, but I have seen cartridge bearings affected by preload in larger equipment.

Kontact

Hubs and BBs generally grab cartridge bearings by the inner race, so no amount of compression is going to affect the relationship of the inner and outer race. That's why you won't see it with your QR. In the same way, you can't adjust play out of such a hub bearing.

hevysrf

[QUOTE=Kontact;22848174]Hubs and BBs generally grab cartridge bearings by the inner race, so no amount of compression is going to affect the relationship of the inner and outer race. That's why you won't see it with your QR. In the same way, you can't adjust play out of such a hub bearing.[/QUOTE

Outer race is captured by the hub, compress the shaft the inners move loser together while the outers remain stationary and they will no longer be aligned. They will bind.
You're right in saying that skewers are no where near strong enough to compress the axle.

Kontact

The skewer is more than strong enough to compress the axle, and you don't understand how your hub works.

Anyone with a loose ball hub can demonstrate this principle in 2 minutes, so please stop telling people you know different.

hevysrf

I don't have a loose axle at the moment, if you do, could you take a photo showing the amount of compression measured with a caliper?

Kontact

How does one measure angular bearing play with a caliper?

sweeks

It's hard to do visually because the change in length is quite small. But as this doesn't apply to your axle, can you just take our word for it?

sweeks

I think he means he wants to see how much the axle length changes.

Kontact

I doubt my .001" measuring calipers would show it linearly. Since the bearing is angular, you can feel it more rocking the axle back and forth. There is only a tiny distance between just right and being able to feel play.

sweeks

A couple years ago, I put a hollow axle in my bench vise and jury-rigged a dial indicator, set to "0" with the axle just barely held in the vise. When I tightened the vise, the dial indicator moved a couple hundredths of a millimeter. I had no good way to compare this to a quick-release, but it *did* confirm that the axle got compressed a bit.

smd4

So a photo would be all you need for proof? Luckily there’s no way to fake those.

The fact that QR axles compress is pretty common knowledge. Why is it so difficult for you to believe it?