Brake problem Driving Me Nuts !

[BJH]

Can anyone out there offer thoughts on this problem.

My winter bike has a set of Tektro brakes which were awaful from day one. Followed the smart advice around on the web to replace the brake blocks and went for the most expensive super compound out there at £20 just for the rubber blocks - no difference whatsoever !

Tried a low price set of Shimano which work great in a friend bike - still the same.

Any ideas ?? I have wondered about cleaning / oiling products that I have used, but my other bike is cleaned in teh same way and I have no issues.

 

[GrasB]

Washing up liquid & a light scouring pad on the rims. Else could be the simple brake/brake leaver compatibility thing.

Personally I think you may be looking at the wrong place as while the Tektro RL520 (Linear pull) rendered my Avid digit-5 V brakes basically non-existent (these brakes I know worked well before changing the leavers), the Cane Creek V-Drop were on par or better than the originally supplied Avid leavers. All I changed between these 3 setups was the brake levers!

 

[gavintc]

You do not state what the problem actually is. Squeaky, lack of power, rubbing ?

 

[BJH]

Sorry, missed the obvious one out. Major lack of power, going down hill and applying the brakes is quite scary stuff. Dura Ace on my other bike would stop like hitting a wall, these ones would leave you more likley to actually hit the wall.

 

[gbb]

Ive got exactly the same problem BJH. Mine are long drop Tektros on the front and Alhongas on the back with Shimano Tiagra wheels.
The wheels are over a year old so the braking surface should have roughened up by now...but the braking ability is awful.

I think some (maybe a lot) of the braking force is lost with flex in the long arms of long drop brakes. Or maybe its just rubbish blocks.

I'm maybe going to visit the LBS tomorrow, i'll let you know what they suggest...and watch this post with interest.

 

[Amanda P]

What about the cables? I've come across cheaper bikes on which, when you squeeze the levers, most of the squeeze goes into compressing the cable outers, rather than force against the rims. Equally, nasty cable inner wires can be remarkably stretchy.

When you buy cut lengths of cable from a bike shop, you don't know what sort of quality you're getting - it can be shockingly poor.

Branded cables from Clarkes, Campangnolo or whoever tend to be rather better for this.

 

[I am Spartacus]

Post a few pictures of the villain... somebody might notice something amiss

 

[AlanW]

A few questions:-

How old are the cables?

How old are the rims?

Are the blocks aligned correctly?

 

[AlanW]

The wheels are over a year old so the braking surface should have roughened up by now...but the braking ability is awful.

This is NOT always the case, if the brake blocks are cheap nasty ones and made of a hard compound, then over time the rims actually get polished. The problem only gets worse there after, the harder you brake the less chance you have of stopping.

Get yourself a Mavic, rim sanding block and gently sand the braking area, remove the old blocks and chuck 'em. Get yourself a decent set, SwissStop, Shimano what ever make/type and refit.

Taking note of a) the direction of the pads in relation to the wheel rotation block alignment to the rim.

 

[BJH]

Replacement pads are Swisstop, checked alignment of the pads to rim, cable appears to be pulling and is in good nick !!!!!!
Coming round to saning the rim - again they are new !

 

[gbb]

What about the cables? I've come across cheaper bikes on which, when you squeeze the levers, most of the squeeze goes into compressing the cable outers, rather than force against the rims. Equally, nasty cable inner wires can be remarkably stretchy.

When you buy cut lengths of cable from a bike shop, you don't know what sort of quality you're getting - it can be shockingly poor.

Branded cables from Clarkes, Campangnolo or whoever tend to be rather better for this.

Now thats an interesting point !!!
I built the bike from scratch. and IIRC the cable inners were new, i think the outers were too, but what quality ?...and maybe they were reclaimed old outers.
Maybe check that out tomorrow,

 

[gbb]

This is NOT always the case, if the brake blocks are cheap nasty ones and made of a hard compound, then over time the rims actually get polished. The problem only gets worse there after, the harder you brake the less chance you have of stopping.

Get yourself a Mavic, rim sanding block and gently sand the braking area, remove the old blocks and chuck 'em Get yourself a decent set, SwissStop, Shimano what ever make/type and refit.

Taking note of a) the direction of the pads in relation to the wheel rotation block alignment to the rim.

Another item on the list for tomorrow.
Thats going to be the case anyway...amazing how long ive monked to myself about it...and done nothing

 

[gbb]

An update...
Cable outers and inners were new..i cant remember what make the outers were but i cant see any compression or movement that may cause a problem.
Front blocks were cartridges of unknown manufacture.
Rear blocks were those one piece Jagwire jobbies.

Put new Aztec pads in the front cartridges and all new Aztec cartridges on the back.
Cleaned the rims with a SwissStop rim cleaner (didnt seem to do much anyway...its more like an eraser, just took a light layer of grime off the rim)

The result....much better braking, but still not as good as normal drop brakes.

But better it is...that'll do for now. Cant help but think i should have got some Ultegra or similar pads. Didnt think to ask what the price difference was.

A good advert for the LBS's as well. The Aztec bits i brought were within pennies of online prices. The internet isnt always cheaper.

 

[BJH]

gbb - what is the Swisstop cleaner like ??

I am confident that this is not an issue with teh cables - pulling the lever has the wheel stopped firmly when stationary. The pads are in the right way round and the blocks were super expensive Swisstop.

I am going for a major scouring of the rims - fairly new Mavics - and blocks and start from scratch.

 

[gbb]

The SwissStop cleaner is like an eraser...medium hard rubbery compound. I cant really say what its supposed to do apart from rub off grime maybe. It certainly doesnt seem to abrade the rim surface. Probably shouldnt have bothered with it.
Thats always my trouble...too tight
They had a Mavic rim block, but it was expensive compared with the SwissStop.
So i always end up compromising...

As a side issue, when i got the old pads off, they were quite worn and shiny, possibly the rubber had hardened.

Like i said, its better....but...


BTW, are your calipers long drop ?