Been having a devil of a time with my mechanical disc brakes. They are so fiddly to set up!! Two problems:
1. The instructions say get the caliper position by clamping with the brake lever- doesn't get close. I positioned by eye in the end.
2. The brake lever doesn't get anywhere near enough pad movement- one finger braking this is definitely not! I've got something useful after hours of fettling and going a little off piste- I partially closed the brake then tightened the bolt that holds the brake cable inner. Seems a bit dubious and certainy not in the instructions!
Had anybody else had this much bother with their Avid BB7s?
Are you using MTB BB7s on a road bike?
Hi,
From my experience it is essential to preload the calliper arm to get good braking. I usually pushed it a few mm before tightening the anchor bolt.
I also found clamping the brake to align the calliper a bit hit and miss. Pretty much did it as you have done most times.
Moved onto the new TRP Spyres, much easier to set up.
Regards
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Follow this guide. They're piss easy to set up if you do it right http://www.twowheelblogs.com/avid-bb7-disc-brake-set-and-tuning
In the process of setting mine up now without the aid of instructions. I've had to fettle mine by using thin shims/washers to better position the calliper and the inside pad, and look for bending/distorting of the disc as you pull the lever to get the pads as close to the disc as possible. Its certainly fiddly and looks like you need to adjust as the pad wears and gets thinner. Not quite there yet.
assuming mtb then you should be using speed dial levers really.
to set up either then back the pads right out and loosen off the bolts holding the caliper.
then wind in the none moving side 2 clicks for every 1 click from the cable attached side.
Eventually the pads will be tight against the rotor and there will be no movement.
Now torque up the caliper bolts.
then equally back of the pads with the same number of clicks each side.
and that should be it.
if they are road bb7s then you will need a close-ish gap from the pad to the rotor, but if they are mtb then the gap can be bigger and you can use the speed dial adjustment to increase the leverage at the lever, so you have a larger gap and less issues with rubbing when mud gets in there.
You should be able to get one finger braking easily.
They are (should be) a piece of piss to set up.
Mount caliper loosely on adaptor.
Twist adjuster barrels on both pads until the disc is gripped firmly in the centre of the caliper (or maybe slightly to one side, I think it says something like that in the official instructions)
Tighten adaptor.
Fit cable.
Dial pads out to the point at which they don't rub on the disc
Take up and cable slack with barrel adjuster
Done.
It's a mountain bike- using Avid single digit levers, although they're pretty old- over ten years now.
Thanks for all the info- there's some really great stuff there!! 🙂
I had to change pads on the rear the friday before last in the dark and rain on a night right - things weren't going so well until I stopped and loosened the caliper bolts and redid the steps I listed above - couple of minutes and then it was done and off I went - should have started like that.
Good idea to carry the little starnet key with you on a ride as the inner adjuster can get stiff - if only Avid would make some decently engineered BB7s 🙁
It would be nice if they weren't...... But YES they almost always are.... problematic.
Wow!What a difference that has made! So much easier. And yes- torx 25 for the inner adjuster, invaluable!!
Did my first set of road BB5's the other day. Guessed at the process but it was roughly as TurnerGuy described. Though I did the following...
Wound the inside pad adjuster in a couple of turns.
Squeezed the lever and tightened the bolts with it squeezed.
Backed out the inside pad adjuster a couple of turns (just enough so the pad was no longer rubbing.)
Adjusted the lever and caliper barrel adjusters until I got the a right amount of lever movement
Was all surprisingly easy.
I think most of the guides do that 2 turns on the fixed side and one turn on the cable side as you tighten up as the rotor is supposed to be slightly towards the cable side - then when the brake is deployed the rotor is pushed over into the center of the caliper to meet the pad on the fixed side.
Moved onto the new TRP Spyres, much easier to set up.
I've never had a problem with my BB7's, although pad replacement can be a little fiddly on occasions but those TRP's look very good.
The Spyres look good - the deciding factor might be whether you can get SS kevlar pads for them...
I always wondered when using the BB7 why no one had done a calliper where both the pads moved. The Spyre sorts that.
I would think any Shimano type pad should fit, changed the original pads for fully sintered ones, much better.
except sintered tend to squeal more than organic...
If you have soggy cables then they're a pain in arse because all your lever travel is used up compressing the cable, so check for that too.
The other thing that can make them a hassle is a warped disk - but that's a pain whatever disk calliper you use. Easy enough to straighten them out.
They are good brakes properly setup. Basically they work by squeezing the disk over to the stationary pad, so the less gap between the stationary pad to the disk the better IMO.
Wish I'd gone to BB7's years ago.
A doddle to set up.
Be nice if they did a posh version that looked a bit more...posh. 😐
But I'm happy with mine.