brake blocks jamming on rims...

[Maz]

Spesh Allez: The brake blocks on the rear wheel were rubbing against the rim, so I widened the gap between them (loosened hex bolt, slackened cable and re-tightened bolt).

However, despite this, the brakes stay rubbing against the rims even when i release the brake lever - brake blocks are not returning to their 'released' position.

Maybe the brake spring on the back wheel is jammed up/rusty? Anyone got any other ideas what might be causing the problem?

Thanks.

really cr*p picture of rear brake attached...the spring I'm talking about is the one you can just about make out...the small double-turned wire in the middle of the pic.

 

[HLaB]

Have you had the wheel off ? you may have put it back slightly skew. The best way I've found to get it right is with the quick release loose, pull the brake hard. Then keeping the brake tight close the quick release skewer.

Alternatively there may be a buckle in the wheel.

Or it may just be that your cables/ brakes need cleaning.

 

[Maz]

Have you had the wheel off ? you may have put it back slightly skew. The best way I've found to get it right is with the quick release loose, pull the brake hard. Then keeping the brake tight close the quick release skewer.

Alternatively there may be a buckle in the wheel.

Or it may just be that your cables/ brakes need cleaning.

Thanks. Last time i had the wheel off was last summer when i had a puncture, but not since then.

I will try the QR-lever trick you mention.

I don't even want to think about the wheel being buckled!

 

[Broadside]

Can you pull the blocks apart or are they jammed so they don't go that far apart? The rear caliper on my Specialized Secteur Sport was not opening fully unless you pulled them apart. They got replaced under warranty. The spring was fine but the caliper arms were rubbing which prevented them opening properly.

If yours were working fine but now are not then I would think it would be worthwhile stripping them down to get any road grime out and giving the pivots a liberal grease. The calipers pick up a lot of crap and grit from the tyres especially at this time of year.

 

[Maz]

Can you pull the blocks apart or are they jammed so they don't go that far apart? The rear caliper on my Specialized Secteur Sport was not opening fully unless you pulled them apart. They got replaced under warranty. The spring was fine but the caliper arms were rubbing which prevented them opening properly.

If yours were working fine but now are not then I would think it would be worthwhile stripping them down to get any road grime out and giving the pivots a liberal grease. The calipers pick up a lot of crap and grit from the tyres especially at this time of year.

By hand, I can pull the brake blocks apart. However, when I next apply and release the brakes, they stay rubbing against the rims.

Excuse my ignorance - which part is/are the calipers? Are they the curved metal arms which hold the brake blocks?

stripping the brake down sounds a bit daunting...i'm bound to lose a washer or something and then wish I'd never done it in the first place. Is it easy to do?

 

[HLaB]

By hand, I can pull the brake blocks apart. However, when I next apply and release the brakes, they stay rubbing against the rims.

Excuse my ignorance - which part is/are the calipers? Are they the curved metal arms which hold the brake blocks?

stripping the brake down sounds a bit daunting...i'm bound to lose a washer or something and then wish I'd never done it in the first place. Is it easy to do?

Ah it sounds like a dirty brake or a stiff cable. Before taking things apart, try some (I'm going to swear now) WD40 on the pivot points of the brake and lube the cables.

 

[Broadside]

Maz - yes I was referring to the curved arms. There is a pivot point at the top where a bolt goes through and attaches them to the frame. It is that pivot point that may be gunked up.

If you don't fancy stripping them down then a good clean, squirt of WD40 followed by some oil when it dries out would be a good idea. Failing that it will be a trip to the LBS, as it is not funny riding with a brake jammed on. If you have to replace the caliper they are only about £20 for the Allez if they are Shimano Sora or Tiagra.

 

[swee'pea99]

Dribble 3-in-1 down the cables, working the brakes as you do it. Plus a wee dribble on the pivot point, as suggested above.

 

[Maz]

Many thanks for the advice.
I'll give the calipers/cable a good clean out and re-lube and see if that fixes it.

 

[Alien8]

If, with the cable detached from the caliper, the brakes open okay it's almost certainly the inner cable binding somewhere. A bit of lubricant down the cable may help but you're probably fighting a loosing battle and would be best to replace the brake cable inner and outer with new.

 

[Maz]

Brake calipers cleans out and re-lubed...working very well now.

Regards
Maz

 

[swee'pea99]

I do like a story with a happy ending...