Disc Brake Trouble. Help me find a solution!

AFCBournemouth

OK, my rear brake squeals & vibrates under braking which made me realised it wasn't centralised. But having had a good look at it this afternoon, I've identified the problem:

The disc has a 'wobble.'

To explain, the centralising works fine. I can look between the two pads & see that the disc is in the middle, but then, if I turn the wheel, the disc moves slightly closer, and then back to the middle, as if it is very slightly buckled. The lateral movement distance is 1mm or less, but in the gap between the pads that's quite a lot.

When I do the same with the tyre, i.e. watch it as it turns, it too has a very slight wobble. (more than 1mm,but still very slight, & certainly not noticeable when riding the bike.) Now, I'm not sure exactly what to do about this, or what's causing the problem.

It's very unlikely I've buckled the wheel. I've only done road riding, two gravel trails & one XC trip through a load of fields so far, no jumps or DH, so the bike *should* have been fine. I think it is possible that running the brake for those trips without centralising the callipers may have warped the disc.

My concern is that the tyre and disc movements are linked, leaving me with a far bigger problem to do with the bearings or hubs. & I have no idea how to work it out.

So, the plan of action is as follows:
1. Buy a new 160mm rotor to see if the rotor is warped.
2. Replace, & see if the problem persists
3. If it persists.... ?????

So for you experts, am I on the right lines? Have I missed something that you'd be trying?

Is it possible that running the rotor whilst badly centralised has warped the disc?

Let's say the replacement rotor has the same wobble, is the next step to buy a whole new wheel?!
pfft this is a bloody pain. I never had this trouble with V brakes

If it helps in any way;
Brakes are Tektro Draco Hydraulics and the Bike is a 2011 Mongoose Tyax Elite.

cooldad

Or service the hubs, if that seems to be the problem.

supersonic

Or true the rotor.

Tim.s

Ignore the wobble in the tyre, even the very best tyres are never perfectly even.

Sounds like your brake is just noisy? If you have only done a few rides on the bike its probably still bedding in, you can eliminate the disc being faulty by swopping them front to rear (assuming they are the same size) then if your front brake starts playing up you know you need to replace the disc.

HandjobDan

As Supersonic said, take an adjustable spanner and turn the wheel until the disc comes into contact with the pads and then follow that point round until you can get the spanner on it and give it a little bend back to straight again.

konastinky888

Is the wheel a quick release? Check it's sat in the frame properly.

nicklouse

AFCBournemouth wrote:

My concern is that the tyre and disc movements are linked, leaving me with a far bigger problem to do with the bearings or hubs. & I have no idea how to work it out.

.

if the rim an disc move together then it is a hub issue.

a buckled wheel has no bearing on the disc.

1 waste of money.
2?
3sort the hub out.