Rear brake judder - is there a classic?

[fish]

Hi,

My TA rear brake judders (pumps), varying with speed. The other key symptom is that the outside brake pad is wearing away quickly while the inside is hardly touched.

I've followed the threads and cleaned everything, copper greased the piston which is moving freely and other stuff. but still it's still the same.

I suppose the next obvious is a warped disc , but like one of the previous posts said, "discs don't just warp".

So before I shell out, I just get the feeling that the pads wearing one side and not the other is a Classic symptom of something.

I was hoping someone would know what that something is?

Fish the Unbalanced
It's making me deaf, but I'm not going to stop doing it.

[Snaphappy]

Not sure how your calliper is mounted but it sounds like it is stuck and not centralising itself
It should be free to move side to side in the mounting bolts. Only needs a fraction but it needs to move.

Discs warp when they are at their hottest and then rapidly cool down ie hard braking, discs red-hot, and hitting a big puddle.

[Lumiya]

easiest way of telling of the disk is warped is to put the bike on the centre stand, get someone to very slightly bit by bitslightly pull in the brakes whilst turning the wheel by hand... If warped then the brakes will start to bind on certain sections of the disk and not others

[AlanH]

As Snaphappy says, it sounds like the caliper sliding mount has seized so the caliper holds one pad against the disc. This causes the disc to overheat and warp which will then cause the juddering.

So, time for a new disc, new pads and a caliper strip and rebuild.

[Knobblywobbly]

Another thing to check - remove the disc and clean off any crud behind it on the hub. The rear disc on my @ appeared to be warped, but once the hub/disc was cleaned it ran true.

[AlanH]

You could always straighten it with a large hammer - the now broken RD04 had that done to its rear disc at some point in its life

[davsato]

is it a floating disc? if so then a stone chip might have wedged the disc over in one of the top hat buttons

[fish]

Ok, thanks for the advice.
Another strip down and clean of the slidey things.
If that fails, disc off and check for crud and warping.
New disc on the card...

Is there a best supplier?


Fish the Unbalanced
It's making me deaf, but I not going to stop doing it.

[AlanH]

Wemoto are pretty good, as are David Silver Spares.