front disk brake / wheel question

bucklb

Hi. I'm new to disk brakes, so please forgive me if this is a daft post.

If I really haul on the front brake (for an emergency stop etc) then there can be a crack noise as the front wheel moves slightly in the fork. I assume this is the force of the brake tugging on the wheel in its mount. The wheel still runs well enough and the brakes still work, albeit not quite as well, until I can reseat the wheel.

The wheel is quick release & I've tried tightening the bolt as much as I can, but I'm aware that there can be times when I need to get the wheel off at the roadside so there are limits. The brakes are mechnanical, rather than hydraulic.

Is there something I should be looking into to reduce this issue (I've wondered about sticking a toothed washer or split washer to try and keep the wheel in place) or is this normal behaviour for disk brakes?

Ta
Bob

nicklouse

sounds like the headset need a little adjustment.

bucklb

Might have been sensible to mention in my original post that I'm not running suspension forks, just "bladed, hi-tensile steel" apparently.

Why would the headset make a difference please (pardon my ignorance)?

Ta
Bob

The Rookie

Play in the headset means it moves from fork lower forward (due to the trail and weight) to back due to the braking force resulting in a noise.

That or your QR isn't tight enough (regardless of how tight it is!) - Shimano are much better than open cam designs!

Initialised

I had this, turned out to be a slightly loose caliper mount.

redvee

Initialised wrote:

I had this, turned out to be a slightly loose caliper mount.

I had this but it showed itself in the form of a squeal when I used the front brake.

kajjal

Generally if the wheel is twisting in the fork under braking this means the QR is not tight enough or defective in someway or there is something wrong with the fork where the QR grips it. This is not normal for disc brakes. Take the bike back to the bike shop and ask them to take a look.

When I had this problem I was not doing the QR up tight enough having been used to V brakes which excert a lot less force at the axel. The advice about checking the mounting bolts are not loose for the rotor and caliper is also worth checking.

anewman

This might be an interesting read http://www.ne.jp/asahi/julesandjames/ho ... k_release/

bucklb

That's a scary article! My wheel does seem to be jolted out of position, but I'm not aware of any loosening of the QR; I'll be keeping an even closer ey on it in future, mind.

I'll double check all the bolts and see about tightening the QR further. I can barely undo it as it is and I'm loath to have it so tight I can't release it at the roadside in any case of unexpected deflations, especially with the inevitable cold hands at this time of year.

The Rookie

That article is pretty old, and it's the only one that seems to have an issue, if you think about it there are millions of disc equipped 9mm QR bikes out there, including in the litigation feeding frenzy pond that is the USA, if there was really a problem......

Get a Shimano QR, by far the best and a lower lever to clamping load ratio.

MichaelW

Check the style of QR spindle. The ones with external cams and plastic bits are not suitable for the forces generated by disc brakes. All-metal Shimano or Campagnolo are the ones to use.
Check that your forks have safety lips.
Check that you are using the QR correctly as a cam lever, not a wrench.