[chris the monikerless]

Hello,

After my ride today I noticed that the front brake was dragging. Turns out the wheel moved a little out of place, I loosened the quick release and the wheel went "thunk" back where it should be. This is the second time it's happened and it's never happened on any of my other bikes. Has this happened to anyone before? The wheel seemed as tight as any other wheel has ever been. What could be causing it?

Thanks.

 

[Master Shake]

Hello,

After my ride today I noticed that the front brake was dragging. Turns out the wheel moved a little out of place, I loosened the quick release and the wheel went "thunk" back where it should be. This is the second time it's happened and it's never happened on any of my other bikes. Has this happened to anyone before? The wheel seemed as tight as any other wheel has ever been. What could be causing it?

Thanks.

Are you using disc brakes? There's a potential on a lot of forks for the tire on the ground acting against the brake caliper to pop the axle out of the dropout. Increasing your wheel size to 29" amplifies this effect. Most fork builders are just figuring this out now. 29" front ends should have 20+mm through axles, but in the mean time, uUse a bolt-on axle & wrench for a secure install.

 

[TomP]

Ti skewer?

Are you using disc brakes? There's a potential on a lot of forks for the tire on the ground acting against the brake caliper to pop the axle out of the dropout. Increasing your wheel size to 29" amplifies this effect. Most fork builders are just figuring this out now. 29" front ends should have 20+mm through axles, but in the mean time, uUse a bolt-on axle & wrench for a secure install.

While I've heard quite a bit about the issue of front disk invoking forces that can pop your axle out, and I don't disagree that the issue is serious, I'm not sure I agree that all 29ers need to use a through axle. LOTS of folks out there, like me for example, run disks on bigwheels with ordinary skewers holding the wheel to the dropouts. I have never had my hub move around in the fork dropout.

But that's probably because I use plain-jane steel skewers and make sure they are tight enough. In my opinion, skewers are one of the applications where stretchy ti is not a good material choice. Especially on the front of a bike with disks. I'm going to guess that the original poster is running some fancy Ti skewer.

 

[Guest]

Skewer

Its not just ti skewers that can be a problem I prefer shimano steel skewers I would avoid the Salsa or similiar cam skewer.

 

[Master Shake]

...But that's probably because I use plain-jane steel skewers and make sure they are tight enough. In my opinion, skewers are one of the applications where stretchy ti is not a good material choice. Especially on the front of a bike with disks. I'm going to guess that the original poster is running some fancy Ti skewer.

Right you are. The idea is, a 26"/disc/qr with an open dropout not aligned to counter braking forces has a relatively small safety margin. A 29" wheel has even less. At this point, how tight your skewers are becomes very important. Using a steel skewer and cranking the hell out of them is a good idea. Using a skewer with a wildly rising mechanical advantage (& steel skewer) like Mavics is a great idea. Bolts & wrenches typically result in higher torques as well, and are a step further in the right direction. Through-axle system solve this problem, as well as stiffen the legs of longer forks. For most of us, the good old campagnolo-style quick release does the job, but from an mfg's perspective, safer is better.

 

[chris the monikerless]

I do indeed have disc brakes. I don't think it's ti skewers, the bike has Shimano xt hubs and I assume they have whatever skewers come with those. I bought the bike used though so I don't know for sure.

 

[20.100 FR]

for good ti skewers, chose only the bolt ons USE spin stix.
Much more rigid than cam designs.

 

[banks]

Then you are not getting them tight enough. Gotta leave the white impression in the palm of your hand.

 

[GlowBoy]

Then you are not getting them tight enough. Gotta leave the white impression in the palm of your hand.

Agreed, I bet that's the problem. On a lot of forks, disc-braking forces can pop the wheel right out of the dropouts. I know guys who've experienced this, and the situation where it happens is often a high speed descent. It is REALLY important to close the skewer securely, even with a good Shimano one.

 

[slim_pickens]

And while you're tightening your skewers so vigorously, don't forget to check and replace them often. They were designed in a time before they had to resist force equivalent to quadruple the braking force at the tire.

The mechanism is described here:

http://www.ne.jp/asahi/julesandjames/home/disk_and_quick_release/

The cause of this problem is well known and there are plenty of examples of it happening regardless of skewer type or tension. If your fork/brake/qr are susceptible, extra tension just buys more time before the skewer comes loose.

Don't be so anxious to blame the user for this problem. A designer or builder can fix this easily by mounting the brake caliper on the front of the fork leg, and can give you a "band aid" solution with a horizontal dropout.