Misaligned brake pad issue

buddhahat

I fitted new brake pads (rear) recently and noticed that one pad is rubbing and noisy. On inspection I noticed the pad is at an angle (see pic). The pad is correctly inserted - it seems to be the pressure plate (not sure of correct term) that pushes the pad in/out that is at an angle. In the attached photo this plate is fully retracted into the housing yet it's visibly wonky compared to the other one.

I can just about align the pads so that the rubbing is minimised but it strikes me that the pad will wear unevenly. Also, the previous pad actually broke and I'm wondering if it was related to this misalignment issue.

Could there be something stuck behind the pressure plate that is causing it to be angled this way? Is it possible to disassemble this part of the brake housing to inspect it? I'm a real newbie when it comes to bike mechanics and don't want to bite off more than I can chew, but at the same time if this is a fix that's doable at home I'd rather avoid LBS costs as have a spent a small fortune there recently.

Any pointers would be much appreciated - thank you.

DeVlaeminck

Dunno, have you eliminated it being a problem with the pad - maybe switch it with one of the others?

buddhahat

They’re new pads and I’ve installed them the other way round to check but the misalignment is definitely caused by the angle of the pressure plate behind being off.

I’m just curious if anyone had a similar experience and whether it would be advisable to start dismantling the brake housing, or whether I should leave well alone.

wilberforce

What make/model of brakes are they?
Can you apply pressure using something like a tyre lever to see if you can push the piston back square to the caliper?

buddhahat

It's a 'TRP - Spyre C'. I tried pushing a bit but it didn't seem to budge. It has a screw in piston that lets you adjust the depth from the allen key hole on the back. But fully retracted it is still wonky. Might have another go at pushing it. Here's a pic:

buddhahat

Thanks for the contributions so far.

I've managed to find the instructions to the brake here: https://www.trpbrakes.com/userfiles/file/SPYRE_Final_053113(1).pdf

But can't find any info on changing the angle of the pistons, beyond the allen key pad depth adjustment.

I have emailed the manufacturer and will update here if I get any useful info.

ugo.santalucia

I've had Spyre and I seem to recall suffering something similar. I think the bottom line is that pads run too close to the disc and any microscopic misalignment or imperfection in the disc rotor results in rubbing and uneven and premature wear. I never quite managed to have L and R pads wearing at the same rate.

I don't know whether full hydraulic are better or suffer from the same issues, judging by the number of thread about rubbing pads, I suspect it's the same thing.

I've tried to align them and fix the issue many times, without success... I then bought a rim braked bike and forgot all about brake issues... I just don't have to think about brakes anymore, and can focus on more enjoyable things

buddhahat

ugo.santalucia said:

and can focus on more enjoyable things

Yes! Seem to be spending too much time worrying about malfunctioning bike parts these days! 😫🥴

ugo.santalucia

buddhahat said:

ugo.santalucia said:

and can focus on more enjoyable things

Yes! Seem to be spending too much time worrying about malfunctioning bike parts these days! 😫🥴

With that in mind, they've always stopped me when I needed them to, so maybe you shouldn't worry about them?

buddhahat

ugo.santalucia said:

buddhahat said:

ugo.santalucia said:

and can focus on more enjoyable things

Yes! Seem to be spending too much time worrying about malfunctioning bike parts these days! 😫🥴

With that in mind, they've always stopped me when I needed them to, so maybe you shouldn't worry about them?

Fair point!