Front wheel pulling to one side when braking and eventually works loose?

[nmfeb70]

Hi all, I guess the thread title explains my problem. I ride a Trek X-Caliber 7 MTB and since replacing the front brake pads the wheel pulls to the left whenever I brake. It eventually works loose and I need to tighten the QR after every 30 - 40 miles. I've removed the wheel and there is no loose movement in the cones? Any suggestions? Thanks!

 

[Ming the Merciless]

How are you doing up the QR and is it internal or external cam?

 

[nmfeb70]

How are you doing up the QR and is it internal or external cam?

I have recently found it easier (rightly or wrongly) to twist the plastic nut rather than turn the lever. As for the cam - I've no idea what that is.

 

[Ming the Merciless]

The QR works by a camming action. So have QR lever in open position. Turn right hand nut. Then you should push QR to closed position via pressure of two fingers. It should be firm but not require your whole hand to close.

 

[nmfeb70]

The QR works by a camming action. So have QR lever in open position. Turn right hand nut. Then you should push QR to closed position via pressure of two fingers. It should be firm but not require your whole hand to close.

By "right hand nut" do you mean the plastic nut on the opposite side of the QR lever or the nut to the inner of the QR lever.

 

[Ming the Merciless]

By "right hand nut" do you mean the plastic nut on the opposite side of the QR lever or the nut to the inner of the QR lever.

Plastic nut

 

[Ming the Merciless]

View: https://youtu.be/Hcq-PwYj3TE

 

[Wobblers]

I have recently found it easier (rightly or wrongly) to twist the plastic nut rather than turn the lever. As for the cam - I've no idea what that is.

I suspect your problem's down to the QR not being tight enough. If it's not done up tightly, the wheel can move under braking - it will indeed move to the left. The QR must be done up tight otherwise it's possible for the wheel to be ejected from the dropouts under heavy braking, at which point you'll go into the ground face first.

Yes, the right hand nut is the plastic one on the other side. Start with the QR lever in the fully open position, ideally pointing downwards. Tighten the nut up until you can move the QR lever about half way to the fork before you start feeling resistance. At that point push the lever fully in towards the fork. It'll need some force: a good guide is that, if you push it using the palm of your hand, it should leave a white mark on your skin afterwards.

 

[nmfeb70]

I suspect your problem's down to the QR not being tight enough. If it's not done up tightly, the wheel can move under braking - it will indeed move to the left. The QR must be done up tight otherwise it's possible for the wheel to be ejected from the dropouts under heavy braking, at which point you'll go into the ground face first.

Yes, the right hand nut is the plastic one on the other side. Start with the QR lever in the fully open position, ideally pointing downwards. Tighten the nut up until you can move the QR lever about half way to the fork before you start feeling resistance. At that point push the lever fully in towards the fork. It'll need some force: a good guide is that, if you push it using the palm of your hand, it should leave a white mark on your skin afterwards.

Yes, that is how I tighten the wheel. Turn the plastic nut clockwise & little by little while the QR lever is released. When I feel a little pressure I lock the QR lever - never too much or too little force.

 

[Wobblers]

Yes, that is how I tighten the wheel. Turn the plastic nut clockwise & little by little while the QR lever is released. When I feel a little pressure I lock the QR lever - never too much or too little force.

You've only had this trouble after you changed the brake pads - presumably you removed the wheel whilst you were doing so? That does point to the QR being the issue.

A QR needs more clamping force than you might expect for a disc brake as disc brakes impose torsional and rotational loads on the axis. The first thing to try is to do it up tighter than you'd normally do. Also, make sure that the drop outs are clean.

 

[nmfeb70]

You've only had this trouble after you changed the brake pads - presumably you removed the wheel whilst you were doing so? That does point to the QR being the issue.

A QR needs more clamping force than you might expect for a disc brake as disc brakes impose torsional and rotational loads on the axis. The first thing to try is to do it up tighter than you'd normally do. Also, make sure that the drop outs are clean.

Thanks. I also tend to hit a few speed bumps at speed on my downhill stretch home which may contribute to loosening of the wheel?

 

[Wobblers]

Thanks. I also tend to hit a few speed bumps at speed on my downhill stretch home which may contribute to loosening of the wheel?

If the QR's a little loose, speed bumps certainly aren't going to help matters. I've not noticed that myself though, but I usually tighten them up until they're "utterly bastard tight", which I believe is the technical term.

 

[ColinJ]

If the QR's a little loose, speed bumps certainly aren't going to help matters. I've not noticed that myself though, but I usually tighten them up until they're "utterly bastard tight", which I believe is the technical term.

That's too tight - I learned that after one exhausting ride during which I couldn't figure out why my bike felt so sluggish. I checked my brakes and they were not rubbing. It turned out that excess QR closing force was squeezing the wheel bearings and causing a ridiculous amount of friction.

It can also be very hard to undo overtight QRs out on the road if you get a puncture.

 

[Wobblers]

That's too tight - I learned that after one exhausting ride during which I couldn't figure out why my bike felt so sluggish. I checked my brakes and they were not rubbing. It turned out that excess QR closing force was squeezing the wheel bearings and causing a ridiculous amount of friction.

It can also be very hard to undo overtight QRs out on the road if you get a puncture.

I've not had that trouble myself - and I figure a little trouble undoing the QR preferable to it coming out when I least want it to. For this last issue I run marathon pluses...

 

[the snail]

As above, if it's an external cam design, they don't work as well, sometimes they have plastic washers that creep and come loose - probably best to replace with an internal cam type (shimano) or maybe skewer with hex nut fastener. I think the issue is made worse because the disc brake force tends to try and force the axle out of the dropout