Road cyclist comes in peace. Avid bb7 pads

seanorawe

I have avid BB7 mechanical disc brakes on my Planet X. Who better to ask about disc brakes, than the people who know them best?

So, I have tried everything and my discs still squeal very loudly on every attempt. They are a few months old and they were never loud at the start, until the bike came back from a service. I took the rotors off, and cleaned them in very hot, slightly soapy water, dried thoroughly and cleaned again using alcohol wipes. They were not as bad, but were still noisy. 20 mins in to a ride and they started squealing bad again.

Could my pads be dirty, and they are transferring oil to the rotors? I was careful to try and bed them in properly, but not entirely sure if that was successful. Will I take the pads out and clean them with something?

One last technical question. With the wheel off, can I take the pads out of a Avid BB7 brake without taking the brake caliper off? Just open the both pads up fully and pull them out?

buddy_club

Sounds like you're brakes were contaminated by oil or something. Clean the rotors again with Isopropyl Alcohol. Replace the pads at the same time - if you keep the same pads they will still be contaminated and they will contaminate the rotors again.

cobba

[url=http://www.bikeradar.com/forums/viewtopic.php?p=19708427#p19708427]seanorawe[/url] wrote:

With the wheel off, can I take the pads out of a Avid BB7 brake without taking the brake caliper off? Just open the both pads up fully and pull them out?

Yes, you can take them out without taking the caliper off.
Turn the outer pad adjuster dial out fully, squeeze the brake lever to push the pressure foot back into the drive cam, turn the inner pad adjuster dial out fully, grab the tabs on the pads with a pair of pliers and pull the pads out.

When putting them back in, the pad spreader will need to be sandwiched between the two pads and both pads will need to be pushed into the caliper together, the two little feet on the pads will need to be clicked into the pad retainer clip.

Isopropyl alcohol is commonly used to clean pads and rotors, if the pads are contaminated, give them a good soak and scrub, you can repeat the process a couple of times with clean alcohol.
Heat from a gas torch or stove can also be used to burn contaminates from pads, if there's oil on them, they can give off a lot of smoke.
I've brought contaminated pads back to life by cleaning a couple of times with alcohol, once the alcohol has evaporated off them I've put them onto a glowing stove hotplate, when they stopped smoking, I let them cool down and re-cleaned again with alcohol.

Burnish – Brake power is generated by the friction material on the pads embedding into the surface of the rotor, re-bonding to the friction material still on the pads and then breaking apart or shearing. In order for this bonding/shearing to occur, the friction material must first be displaced onto the surface of the rotor. This typically happens during the first 10 – 50 stops of a brake system and is referred to as “burnishing” the rotor and pads. When a rotor is cleaned, it will need to be re-burnished again to re-deposit the friction material onto the surface.

Scratching the surface of the rotor can help with brake squeal.
http://www.pinkbike.com/news/Tech-Tuesday-Silence-That-Squeaky-Disc-Brake-2011.html

BB7 Installation & Setup: https://sram-cdn-pull-zone-gsdesign.netdna-ssl.com/sites/default/files/techdocs/2006_BB5and7_English.pdf

BB7 Service: https://sram-cdn-pull-zone-gsdesign.netdna-ssl.com/sites/default/files/techdocs/gen.0000000003513_rev_b_2012_bb7_bb5_service_manual_english.pdf

codfather

[url=http://www.bikeradar.com/forums/viewtopic.php?p=19708427#p19708427]seanorawe[/url] wrote:

I have avid brakes

There's your problem...

If the pads are properly contaminated then your only real option is to ditch them and put a fresh set in after cleaning the rotors. I don't know about Avid mechanicals but every set of Avid hydraulics I have used has made a hideous noise fairly consistently

seanorawe

Thanks for the replies. And thanks coba for the lengthy reply

So I took out the pads and they were greasy, so I cleaned them up with water and a microfiber cloth then baked them for 15 mins at 200 degrees.

When I took the pads outs the springy clip thing came with them. So putting them back in I put the clip back on and pressed the pads together them re inserted in to the caliper. It went in much easier than it came out. But now I cant stop the pads from rubbing the rotor. Im going to do a brake adjustment from scratch to see if that helps.

Can someone clear something up? I put the pad marked R to go to the right as im looking at the bike. I.E the R pad is where the bigger red pad adjuster is, the one a torx screwdriver fits in to. Is that correct?

THe easy thing to do is bring it to a mechanic, but I wont learn, if I don't make mistakes.

cooldad

Right would normally be the right side looking forward as if you were sitting on the bike. If that makes sense.

cobba

[url=http://www.bikeradar.com/forums/viewtopic.php?p=19708919#p19708919]seanorawe[/url] wrote:

So I took out the pads and they were greasy, so I cleaned them up with water and a microfiber cloth then baked them for 15 mins at 200 degrees.

You will need something a bit stronger then water and you'd need a bit more heat then 200 degrees if you want to give them a good clean.

When I took the pads outs the springy clip thing came with them. So putting them back in I put the clip back on and pressed the pads together them re inserted in to the caliper. It went in much easier than it came out. But now I cant stop the pads from rubbing the rotor. Im going to do a brake adjustment from scratch to see if that helps.

Can someone clear something up? I put the pad marked R to go to the right as im looking at the bike. I.E the R pad is where the bigger red pad adjuster is, the one a torx screwdriver fits in to. Is that correct?

Did the feet on the pads line up with the retainer clip and did they click in?
It might take a bit of force to make them click into position, I usually push them in with a pair of pliers.

seanorawe

Did the feet on the pads line up with the retainer clip and did they click in?
It might take a bit of force to make them click into position, I usually push them in with a pair of pliers.

They def did not click putting them back in. I think I have put them in the wrong way round. It says in the manual to out the R pad in spoke side.

seanorawe

Thanks everybody, I can now confirm that the brakes are back in and working correctly. Slight bit of noise when braking but nowhere near as bad. Im going to get some new pads, the ones it came with are terrible

bob6397

Some noise is inevitable - whether from crud between the rotor and the pads (this can clear if you drag the brakes a bit..) ot simply becuase it's a bit wet.. I have Avid's on my MTB and my rear brake is really loud when it's damp - I suspect I have something on it though..

A completely silent brake system is one which isn't actually working - there will always be noise when using a friction contact unless you are actually in a vacuum.

R being to spoke side would be correct - Sit on the bike like you are riding it and then that is your reference point. Your right is the bike's right..

bob6397

seanorawe

[url=http://www.bikeradar.com/forums/viewtopic.php?p=19709365#p19709365]bob6397[/url] wrote:

Some noise is inevitable - whether from crud between the rotor and the pads (this can clear if you drag the brakes a bit..) ot simply becuase it's a bit wet.. I have Avid's on my MTB and my rear brake is really loud when it's damp - I suspect I have something on it though..

A completely silent brake system is one which isn't actually working - there will always be noise when using a friction contact unless you are actually in a vacuum.

R being to spoke side would be correct - Sit on the bike like you are riding it and then that is your reference point. Your right is the bike's right..

bob6397

Cheers bob. Its back to normal thank god.

swod1

depending on where you live you could give resin/organic pads a try over sintered pads that will make noise if they get wet.

seanorawe

[url=http://www.bikeradar.com/forums/viewtopic.php?p=19709954#p19709954]swod1[/url] wrote:

depending on where you live you could give resin/organic pads a try over sintered pads that will make noise if they get wet.

I thought about it, but Ill using this bike throughout the winter, and living in Northern Ireland it rains a lot.