Rear Brake Issue

[Dzzi]

Hi

Having an issue with the rear brake on my 2011 spez sectuer elite, it's the original caliper.
Basically if i adjust the pads correctly (and the wheel is true) they seem to fail to open back up again after application? Hopefully that makes sense?

To "fix" this I've basically open-ended the jaws up using the adjuster thingy on the calliper, this however reduces the effectiveness pretty dramatically! which is sometimes an issue approaching a right hand turn at the bottom of any sort of slope.

Thanks

Dave

 

[accountantpete]

Hi Dave - it is difficult to advise precisely without knowing the calipers but usually the cause is that friction or muck develops which is stronger than the spring.

Friction can develop when the grub screw holding the arms in position on the axle of the brake slips. Muck can also get in the same area and rust things up with the same result.

The only solution is a crash course in how brakes are taken apart and put together - take the calipers off and there should be a lock nut on the axle. This may have a grub screw.

The easy first step is to undo the grub screw a couple of turns and them undo the lock nut fractionally. Re-assemble and see if that works - otherwis you may have to disassemble completely (good practice anyway!) bearing in mind that there could be up to 5 grub screws in there somewhere so if something doesn't unscrew easily check for a GS.

 

[Dogtrousers]

Could be a problem with your cabling. When you apply the brake you squeeze the lever with your hand, when you release it the spring in the brake pulls the cable back.

If the cable isn't running freely (eg - if the cable has a kink in it which is sticking inside the cable housing) the spring will have to pull the cable against the obstruction. And as it's not all that strong it may fail and therefore not release.

Try disconnecting the cable from the brake. If the brake opens up OK then the spring is strong enough to open the brake. Now try pushing and pulling the cable with one hand while operating the brake lever with the other, there should be very little resistance.

 

[Dzzi]

Thanks both, i had a look during a post ride clean up there is some rust visible on the spring, and i can't remember if ive ever replaced the cable so i suspect a combination of issues that you've both highlighted. Think i will bite the bullet and take it off..its not really working anyway so i can't really make it much worse right :-) ?

 

[Dogtrousers]

Note that my advice comes from practical experience on olde fangled brakes from the days when men were men and brake levers were brake levers - not combined brake lever/gear changer/teasmade arrangements. In those days there was one spring - the one in the brake, and you used the force of your hand against that. If you had kinked the cable (eg by turning your bike upside down, in them days the cables came out of the top of the levers) your hand strength would be equal to pulling the cable through the housing, but the spring in the brake, being weaker, couldn't pull it back.

Now - modern setups may be different. I can't think why, but they may be.

 

[Dzzi]

i've never turned my bike upside down she wouldn't like it......

 

[Smokin Joe]

On a 2011 bike with the original cable I'd bank on that being the problem.

 

[Colin_P]

Assuming it is a duel pivot caliper of some description; is it just one block that drags or is it both?

If both, do as advised above, take the caliper off, dis-assemble it, clean it, lube it, put it back.

If it is just one side, then look at the adjuster / centering screw.

 

[Dzzi]

ok great thanks Colin, i'll try to work out, i did notice that i seem to have one pad toe in and one pad toe out...thats not right is it ?

 

[mjr]

I agree that cleaning is the first thing to try.

If you had kinked the cable (eg by turning your bike upside down, in them days the cables came out of the top of the levers)

Only if you turned the bike upside down without supporting the bars! Turning bikes upside down simplifies various tasks and is yet another example that anyone obeying the velominati is a masochist.

the days when men were men and brake levers were brake levers

That, however, is pure genius.

 

[Dogtrousers]

Only if you turned the bike upside down without supporting the bars! Turning bikes upside down simplifies various tasks and is yet another example that anyone obeying the velominati is a masochist.

I don't think the velominati existed when I learned not to kink the brake cables where they emerged from the tops of ye olde Weinmann red-dot brake levers.
But we're getting off topic.

 

[Colin_P]

ok great thanks Colin, i'll try to work out, i did notice that i seem to have one pad toe in and one pad toe out...thats not right is it ?

Toe in and out of the blocks is another issue altogether and shouldn't be much of an issue on road bike duel pivot caliper brakes. Terminology can be confusing!

If your block rubs and the other is free though, it will be a centering issue.

Looking at the below, simply get a screwdriver on the centering screw, it is either clock or anti clock to center.

 

[Dzzi]

Brilliant thanks for taking the time to show me that i will go and take a look today/tomorrow

 

[Dzzi]

also wasn't sure if the comment re obeying the rules making one a masochist was a good or bad thing

 

[Colin_P]

Brilliant thanks for taking the time to show me that i will go and take a look today/tomorrow

Your welcome, shout if you get stuck but it is really easy to do. But someone else suggested way above it would be a good idea to strip them down, clean and lube all of them.

also wasn't sure if the comment re obeying the rules making one a masochist was a good or bad thing

Some rules deserve to be broken.