brakes lowdown

i have a giant roadbike with shimano caliper brakes. Recently the whole apparatus shifts to one side or the other- leaving one brake pad in contact with the rim. Obviously I have tightened the hex nut behind the frame, by which the brakes are connected, but this has had no effect.
I am guessing now the best thing to do is loosen the hex nut fully, and check the whole mounting apparatus front and back.
Anyone had this problem or suggest a way to proceed?

Yes, loosen the nut first, centre the calipers and re-tighten.

Personally, I’d take the caliper off, first, and give it a thorough clean and lube. It may be that it’s full of crap which is hindering the spring return ability. i.e. it’s getting stuck. :wink:

Of course, it may be that the wheel is off centre or the rim is bent/warped/out of true. Have you checked it’s seated correctly in the dropouts, and does it spin true?

It sounds like the nut or the shimmer are worn out.

Take a picture of the caliper, if you are lucky it could have a tiny screw for centering the caliper.

This.

@serendipityfox check this picture out:

Note that there’s a “centering adjusting screw” somewhere in the top - right side. IF you have one, you can try it first. It will probably tend to move again, so a bit of blue loctite can help.

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OP if all the above doesn’t fix it. Try checking the center fixing bolt and seeing if it’s loose.

I’m also on Shimano and have had the problem of that screw not being able to be fully tightened. Resulting in the calipers slowly shifting to one side after I “tighten” them.

Grand set of responses, thankyou, thanks for the picture. Yes it’s time I take it apart, clean it and figure it out. The wheel is good. Yes Ranlee you’re right, this is the problem i been having- movement even after tightening.

I sent it over to the shop and had my mechanic friend take care of it.

I can’t give you a very detailed response since I wasn’t 100% sure what he actually did, but he did say he removed the caliper, took it apart, cleaned it, used a sealant of some kind on the bolt and let it sit for 24 hrs. He said the sealant was to prevent the screw from “slipping” or “move” after it has been screwed.

It’s does not have the same clearance as what the my rear brake calipers have, but it has been fixed.

If you want to know what the sealant was, I can ask for you.

Most likely the loctite blue @mad_masala was referring to.

Have you seen the screw I said?

yes have screw- will check screw looseness ASAP (no allen keys here).
So you believe it is center adjusting screw looseness not centre fixing bolt/apparatus? will check.

It could be any or even both.

hehe, good answer

Blockquote

i have enough on my plate for now, disassembling and cleaning calipers. thankyou.

And probably the answer is the latter…

I’d start by using the screw I said. My rear brake has a problem with this screw, and I’m sure that it will be pretty OK if I ever used loctite to fix it… but I don’t have and it’s not cheap I think. I might try some not so strong glue… :stuck_out_tongue:

Seems like @Liub and @mad_masala have already beat me to it.

Not sure if my friend used loctite, but definitely used something similar.

Get yersel’ some Campag brakes. Problem solved. :wink:

it is the quick release! causing the wheel to be out of true. embarassingly i have been looking in the wrong place.
never mind I am grateful for deepening my bike learning - thanks for the knowledge.

cough :wink:

So now i want to get my interpretation okayed…
The guy in the shop insisted the problem was the skewers…
so when i go over bumps, the wheel is knocked out of true, because the quick release is not tight, causing the brake to be bumped out of true. the wheel then returns to true, leaving the brake out of true as the only evidence of the problem