Sticky brakes

Simonb256

Hi all!

This has been plaguing me for a while now...

My rear brake sticks on.
When it sticks theres a tonne of slack cable under the top tube.

It has done this with two calipers.
It was originally thought to be the caliper rubbing the frame (it was slightly) I have no spaced the caliper slightly so it doesnt rub, still sticks.

I have taken the cable out and covered it in WD40 and removed the cr*p fromt he outter, it moves trough the outter fine, but still sticks.

Ideas/suggestions??

biondino

Are the internals of the brake lever gunked up? Do you have anything attached to the frame (a pump, say) that interferes with the cable (this is what happened to me and it took me weeks to figure it out, oops)?

Simonb256

biondino wrote:

Are the internals of the brake lever gunked up?

Possibly, the caliper is geting a wee bit stiff when im adjusting it by hand now. I'll give it a good clean as soon as I can.

Do you have anything attached to the frame (a pump, say) that interferes with the cable (this is what happened to me and it took me weeks to figure it out, oops)?

This I thought of, as the battery to my front light is attached via velcro to the top tube, but even if its not attached it still occurs.

whyamihere

If you have time, drop by mine on your way home tonight and I can have a look if you want?

Simonb256

whyamihere wrote:

If you have time, drop by mine on your way home tonight and I can have a look if you want?

I was after some motivation to cycle back today lol. Oh and I can finally give you back your light.

Oh and the new wheels are on her now. Though the Fulcrum were out of stock so ended up with Shimano SR20's.

whyamihere

I can show you my new commuter bike too.

Simonb256

whyamihere wrote:

I can show you my new commuter bike too.

Ahh cool, shes finally built? (or is this a differnet bike).

Ahh,, i cant even start getting ready to ride til after 5:30 today so no idea when I'm going to get up there (I;d say between 6:30 and 7:00).

Just as a guesstimate, and to be a b*stard I cant remember the way from turning off the main road heh.

My memory isnt what it used to be...

whyamihere

You've seen the frame before last time we rode together, it's just been truly commuterised now. Left off the main road, then right, then left at the end and straight on, let me know if you need any extra directions.

whyamihere

I'm happy to report that the brake is no longer sticky. One of the pivot bolts was too tight, meaning the arms couldn't move past each other very well. Loosening the bolt a fraction cured the problem.

Simonb256

whyamihere wrote:

I'm happy to report that the brake is no longer sticky. One of the pivot bolts was too tight, meaning the arms couldn't move past each other very well. Loosening the bolt a fraction cured the problem.

Indeed that was the case, which was odd.

Took me an eon to get home for some reason (50mins) but meh.

Thanks you very much for having a gander btw.

Next I shall be playing with the allignment as the drive side pad always touches well before (front and rear). Oh and the wheels are already out of true.

Anyway.... sorted, thank you!!

ris

whyamihere wrote:

I'm happy to report that the brake is no longer sticky. One of the pivot bolts was too tight, meaning the arms couldn't move past each other very well. Loosening the bolt a fraction cured the problem.

don'tsuppose you are passing the chippenham area anytime soon whyamihere, my rear brake is driving me up the wall with what seems to be the same problem as Simonb256 was experiencing!

tiagra brake on a specialised allez sport 08, about 5months old. if i trim the brakes up then the first pull locks them on with little return the brake cable slackens out under the top tube.

i took it into the dealer i bought it from and they fiddled with it so that it worked for a week or so, but it started sticking again and i can't get it right at all. they suggested it might be the cable sleeve or gunk in the brake but even after cleaning the brakes out thoroughly, stripping the sleeve off and wiping the cable clean it is still sticking.

i could get to grips with the v-brakes on my airnimal but these are very frustrating! which ones are the pivot bolts? i've not adjusted any of the assembly parts (apart from the main connecting bolt to the frame so i could take the brake off the frame).

sorry to ramble but i'm not getting my usual bike time... it may be affecting me. :oops:

biondino

Did you wipe the cable TOO clean, maybe? Should it be greased (I have no idea but it seems logical if you want less friction)?

whyamihere

Loosen the circled bolt very slightly. If it works, then you'll see a washer behind the bolt, between the arms. You can either leave it in its slightly loosened state (not a problem, but it's a good idea to check it isn't working any looser occasionally) or, if you're feeling brave, you can remove the bolt and washer and grease it.

WARNING: When you remove the bolt, the brake will very probably explode. It'll be tricky, but possible to get it back together. Alternatively, just drip some good oil in there...

ris

thanks biondino and whyamihere, just about the only nuts i didn't try to loosen while cleaning it down was the one you circled, but i tried it late last night and it didn't appear to make any difference - the brake just seemed to be loose to itself. when i tightened it up i tried a few levels of tightness. my description of thorough was perhaps a bit misleading, i didn't strip it down completely. it seemed to work pretty freely when it wasn't connected though, didn't seem to be sticking.

after i wiped the cable down i put a bit of anti-friction spray on it to prevent it rubbing in the sleeve, as the dealer suggested that water getting into the sleeves can cause the cables to stick.

i think i might have to take this one to the lbs for a proper look over, which i don't mind doing if only i could work out what actually wrong so that i could understand it next time!

whyamihere

Right, time to bring out whyamihere's Super Special All Purpose Guide To Diagnosing Problems With Brake Calipers.

1. Squeeze the lever so that the brake sticks on. Make a note of where the cable goes slack (most likely along the top tube)
2. Release the lever, and check if the lever returns to its normal position (there is a spring in there, so it should)
3. Release the cable. Does the caliper spring back?
4. Pull the rearmost cable run (from the top tube down to the brake caliper) out of the cable stops, and 'floss' it along the inner cable. Does it feel sticky?
5. Same with the front cable run, but as the outer cable is under the bar tape, you will need to pull it out of the cable stop on the top tube, pull the lever to expose the bead at the end of the cable and push it through, then floss the inner cable. Again, does it feel sticky?
6. Activate the caliper by hand. Push the pads to the rims, then let go so that it springs back. It should spring back very quickly, if it's sticky it will be quite slow at springing back.
7. Check the adjuster bolt on the caliper. Is it grimy? (I'd assume not as you've already cleaned it.

Let me know your answers to these 7 and I'll see if we can get it worked out.

antfly

I have this same problem with my tiagra rear brake.Try taking the brake off and dropping it {without the pads}into boiling water,it`s easier than taking it apart and it seems to have worked,along with cleaning and oiling the cable.
When I put it together the thread was gone on the circled bolt so I had to get a new one which wasn`t easy.

biondino

antfly wrote:

I have this same problem with my tiagra rear brake.Try taking the brake off and dropping it {without the pads}into boiling water,it`s easier than taking it apart and it seems to have worked,along with cleaning and oiling the cable.
When I put it together the thread was gone on the circled bolt so I had to get a new one which wasn`t easy.

I love this! Was your thought process "well, it works for teabags and lobster so obviously it'll sort out my brakes"?

antfly

Yes,if anything gives me a problem I just drop it in boiling water for a few seconds,it works wonders!
But seriously someone on another forum suggested it to me after they dit it on advice from their LBS.
It gets rid of all the salt and road muck very well,apparently.It worked for me anyway and if there`s an easy way and a hard way I prefer the easy way.

ris

whyamihere, you should probably get a tm or c symbol to go with that!

i'll set to it this evening, my gut feeling at the moment is that maybe the calipers still just aren't clean enough at the pivot. my feeling that they weren't sticky when off the bike might have had something to do with them having been handled and moved a lot. i think i might need to properly strip them to get them springing back properly.

thanks for all the help and suggestions, maybe i'll give it a boil wash first!

ris

whyamihere wrote:

Right, time to bring out whyamihere's Super Special All Purpose Guide To Diagnosing Problems With Brake Calipers.

1. Squeeze the lever so that the brake sticks on. Make a note of where the cable goes slack (most likely along the top tube)
2. Release the lever, and check if the lever returns to its normal position (there is a spring in there, so it should)
3. Release the cable. Does the caliper spring back?
4. Pull the rearmost cable run (from the top tube down to the brake caliper) out of the cable stops, and 'floss' it along the inner cable. Does it feel sticky?
5. Same with the front cable run, but as the outer cable is under the bar tape, you will need to pull it out of the cable stop on the top tube, pull the lever to expose the bead at the end of the cable and push it through, then floss the inner cable. Again, does it feel sticky?
6. Activate the caliper by hand. Push the pads to the rims, then let go so that it springs back. It should spring back very quickly, if it's sticky it will be quite slow at springing back.
7. Check the adjuster bolt on the caliper. Is it grimy? (I'd assume not as you've already cleaned it.

Let me know your answers to these 7 and I'll see if we can get it worked out.

it was number 6 that gave me the clue to what it might be - when i worked the caliper by hand it wasn't spinging back against my hand very much. i took the brake off and disassembled it completely, cleaned it up and reassembled it.

it was still sticking and then i remembered what biondino said about it being too clean and put a couple of drops of lube at the washers on the pivot points. that seemed to do the trick and they sprang back properly.

it took me a while to get the bolt tensions right on reassemblyt to stop the brakes from sticking again, but they seem to be working properly now. they look very clean as well, i just need to keep them that way!

thanks to everyone who has helped with this, and particularly to whyamihere - the list really helped me work through systematically where the problem was. it might have been a struggle to work it out but i feel more confident i could look after the calipers properly now, and i prefer to do my own maintenance if possible.

whyamihere

Glad I could help.