Caliper brakes problem!

rob w

Hi,

Was out for a short cycle today, and noticed a problem on my rear brake after i got home! Its a caliper brake and the quick release lever wont twist properly around to disengage the brakes, the bolt which holds the cable in place is mounted on the lever, and it wont rotate fully around to allow the brakes disengage..... its not affecting the performance of the brakes, im just worried that it may cause a problem if i need to remove the wheel! It might be a simple solution like just adding a bit of lube or something, just not sure and thought id ask here first!

Thanks

Mcofferon

Hi Rob W
Is your cable under much tension? Obviously this shouldn't be causing the problem, but easy enough to check. Slacken off the adjustment (remembering where it is) and see if the release head will rotate freely when there's no tension? You might have a flat spot in the cam that makes rotating it hard under pressure.

As for getting the wheel out if needed, it kind of depends on the tyre size, 23 or 25 should get past your blocks without much trouble.

Mike

rob w

Mcofferon wrote: »

Hi Rob W
Is your cable under much tension? Obviously this shouldn't be causing the problem, but easy enough to check. Slacken off the adjustment (remembering where it is) and see if the release head will rotate freely when there's no tension? You might have a flat spot in the cam that makes rotating it hard under pressure.

As for getting the wheel out if needed, it kind of depends on the tyre size, 23 or 25 should get past your blocks without much trouble.

Mike

Thanks for that, ill check it out tomorrow and post back how i get on! Yeah the tyre is a 23 so hopefully will be ok!

rob w

Let the tension off the cable as you said and it still doesnt want to disengage. Thinking maybe a bit of dirt or grit has got into it somehow and is jamming it up, ill get a bit of wd40 in to it and see if that loosens it up a bit!

Mcofferon

rob w wrote: »

Let the tension off the cable as you said and it still doesnt want to disengage. Thinking maybe a bit of dirt or grit has got into it somehow and is jamming it up, ill get a bit of wd40 in to it and see if that loosens it up a bit!

Hi Rob.

There might be a bit of a clue in seeing how the cable is effected when its loose and you try to move the QR lever. I'm assuming a shimano style dual pivot brake.

When the cable is loose (enough play that you can easily move it with your fingers) try moving the QR as much as it allows. Does the angle of the cable change with the movement of the QR lever? If it does then the centre cylinder - that forms the cable grip - has siezed to the QR cam. otherwise if thats fee to rotate its the QR cam itself or one of the locating washers thats your problem.

If you are stripping it down and cleaning it, make careful not of the position and sequence of any washers as they are key to the operation

Mcofferon

Heres a diagram of typical QR assy.


DONT LOOSE THE BALL BEARING IF YOU TRY STRIPPING THE WHOLE THING !:rolleyes: