Brake Problems

[dillwill]

I have been diving into more bike maintenance recently and have had a problem with my pads rubbing the rotor on my rear wheel. I have Avid elixer 5 hydro brakes on 180 rotors. No matter how many times I adjust the caliper i still get a bit of rubbing at one point in the rotation. I have heard that it could be a bent rotor or that the wheel is no longer true. The rotor appears to be strait. Is there an easy way to tell what the problem is? I'm saving a trip to the LBS as a last resort.

[zebrahum]

If it's only rubbing in one spot it's probably a warped rotor. Check out youtube on how to true a rotor. It doesn't take much to rub but a light touch in truing rotors will go a long way.

[dillwill]

If it's only rubbing in one spot it's probably a warped rotor. Check out youtube on how to true a rotor. It doesn't take much to rub but a light touch in truing rotors will go a long way.

Thanks! I will give that a shot tomorrow. How often does one have to true a wheel? I have shimano wh-mt15s if it matters.

[cobba]

[dillwill]

That is the video I watched just a few minutes ago ha! Thanks for the reply.

[Bataivah]

If it's only rubbing in one spot it's probably a warped rotor. Check out youtube on how to true a rotor. It doesn't take much to rub but a light touch in truing rotors will go a long way.

Yea. And some calipers suck at returning to open position too. Mainly the single piston type on lower to mid level ones. My old magura used to rub and got worse as the fluid
heated up. Now I went to Hayes strokers w/duel pistons and it's all fine now. Rubbing in
one place has to be something out of true though. Mine dragged all the way around.

[zebrahum]

Thanks! I will give that a shot tomorrow. How often does one have to true a wheel? I have shimano wh-mt15s if it matters.

Truing wheels is different than truing rotors. For a disc brake bike the "truness" of a wheel does not affect the brakes. For a disc brake that is rubbing it can only be the rotor out of true or the rotor not in the correct position in the dropouts.

For instructions on how to true a wheel consulting youtube is probably your best bet.

[Bataivah]

Don't true it if it's not bad though. Once you break the thread seal on the spokes you will be truing it
alot more since the nipples wont be locked anymore. Unless you have the self-locking type nipples.
Idk what type your wheelset has. Always a good idea to check them and the rim every few rides or so.
I give my spokes a qiuck sqeeze now and again to make sure I don't have any loose ones and I'll check how true it is whenever I take the tires off besides the occasional wheel spin/gander lol.

[alex_am]

My friends bike does this. I think he said it's because he went to a larger sized brake and then his QR was already bent from overtightening?

[mjduct]

tell your friend that QR's are cheap, thru-axles are a great upgrade and his logic doesn't make sense =]

If your axle of any type is bent you will have the brake rub constantly on one side or the other, not wobble and only rub at one part of the rotor.

[mack_turtle]

I have found that some disc calipers, especially Avids, have problems with the pistons sticking in the caliper instead of sliding back in smoothly. if this happens, you need to clean the outside of the pistons and lube the outer edge of the pistons. I am sure there's a youtube video that demonstrates this, but at least here's one that illustrates the problem- Formula RX stuck piston - YouTube

[dillwill]

Update: I had to use pliers delicately (with a clean rag of course) to get the rotor true, buts its spinning like a champ. Thanks everyone!

Mack: thanks for the info, I have heard about cleaning the pistons. Thankfully, my pistons compress and release properly. Do I just need to clean the piston or does it also need lube? If it does need lube, what kind of lube would you suggest?

[Alvaaro]

I also have the same problem with my bike

[Alvaaro]

The brake system always attach to the wheel so i can't ride it fast

[Alvaaro]

when ever i try to loose it .... that time it make me horrible

[Alvaaro]

when i tights and when apply brake it makes noisy sound

[Alvaaro]

Any body know ho to handle this situation

[rangeriderdave]

Alvaaro,What's the question?

[dillwill]

I have found that some disc calipers, especially Avids, have problems with the pistons sticking in the rotor instead of sliding back in smoothly. if this happens, you need to clean the outside of the pistons and lube the outer edge of the pistons. I am sure there's a youtube video that demonstrates this, but at least here's one that illustrates the problem- Formula RX stuck piston - YouTube

What kind of lube should i use? Im assuming a dry lube?

[(-_^)Doomcalibor]

I Also have same problem