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Anyone any tips for fine tuning (Road)Avid BB7s? Maybe I'm expecting too much, but they don't seem any more effective in the dry than cantis. I've followed the setup instructions.
decent pads, rotors and cables for one thing.
They're straight out of the box - Avid rotors, sintered pads. Cables are Shimano slr(?) outers and Clarks inners.
Pads bedded in a bit? Get a bit of water and grit on them and brake hard a few times.
Mine are much better, but maybe my canti setup was terrible!
The one thing that erks me a little is that being a dullard I hadn't realised that with these mechanical BB7s only one pad moves and presses the disc against the other. All my previous experiences of discs had been with hydraulic systems and both pads moving. This meant my (still crap but can get away with it) method of applying the brake with the post mount bolts loose and then nipping them up to get the brake aligned and centred to the rotor was next to useless. Actually following the instructions that came with them to get them aligned rather thinking I knew better helped a lot!
Check pads are bedded in and do follow the Avid instructions as previously mentioned. The discs are not meant to be centred in the calipers and if your brake levers have barrel adjusters - only use these to remove any slack in the cable - not to adjust brake lever travel and related pad movement.
not sure about cantis but a well set up v brake is excellent in the dry ('til it overheats, I guess)Maybe I'm expecting too much, but they don't seem any more effective in the dry than cantis
OK, thanks. I haven't noticed sintered pads in my hydraulic discs needing so much bedding in, though, and I've had a good few over the years. Does anyone else think that the inboard pad adjuster is ridiculously stiff?
do they need to be as powerfull? presuming you are using them on the road.
yeah, or at least ridiculously low profile knurled "grips" on itinboard pad adjuster is ridiculously stiff?
A mistake I made with mine was not pushing the pads in until they clicked into place, meaning they weren't properly in the calipers and were contacting the discs at an angle - ooops!
Great, my BB5s are as bad as this. Have bought a set of BB7s as I heard they are much better. Guess I'm going to have the same problem 🙁
Had a really good play with the set up - rear one seems spot on but the front seems absolutely dead. Might chuck them in the oven tonight see if I can burn off any crap on them. Hydraulics in that state clean off after dragging them down a long hill, haven't managed that on the cable ones.
Well, I would have expected a performance improvement over cantis - after all they cost more and are heavier. I agree that on the road one doesn't need the same as for an MTB. I guess I expected that they would stop with little effort and offer good modulation. Anyway, there are a few setup tips on t'internet, I'll try them. Also, it appears that the inboard pad is best adjusted with a torx driver.
Does anyone else think that the inboard pad adjuster is ridiculously stiff?
The silver bit in the centre will accept a Torx bit
Road BB7s are a bit susceptible to slack cable so make sure that you have as little cable flapping around as you can reasonably manage
Yep, the inboard pad adjuster is crazy stiff, and it's ripped half my thumbnail off before now as I've tried to turn it. Why they didn't put a better profile on it I do not know. It's impossible to turn in the cold and wet once it's got a bit of mud and grit on it.
The BB7s are usually marginally better than cantis, but I end up using organic pads in them to make them grab a bit better.
Also, what everyone else said - the setup procedure is not what you'd expect (if you're used to hydros) - make sure you follow the instructions.
My new CX bike came with BB7s fitted.
I was a bit sceptical about cable discs, but the seem pretty damn good to me. They can easily brake a lot harder than the tyres can possibly cope with.
Only annoying thing is the very slight rub from the non-moving pad.
The silver bit in the centre will accept a Torx bit
+1, plus all the stuff they've already said - as much power and modulation as I can reasonably deal with from both my road BB7's sets.
Took me a while to get mine right but now they are spot on. Here's what I did:
1. Follow avid instructions to set pad clearance
2. Set barrel adjuster on cable so it is in middle position (so you can add and remove tension)
3. Slacken cable completely (and leave loose), and rotate the brake arm so the brake is fully on. Do cable bolt up so brake is 'fully on'. Brake lever should be solid now (i.e cannot be moved)
4. Using barrel adjuster, slacken cable until there is clearance
Using this method, the feel of my brakes feels pretty similar to my SLX on my mtb.
When the rotor is in the caliper I think it has to be closer to the none moving pad than the one that moves, ratios like 1/3 and 2/3rds or something.
So I wind out both pads and then wind them in with one click on the non-moving side and two clicks on the moving side, until the rotor is clamped tightly in this position.
Then I do the bolts up and then wind the pads out equally.
I think that is right, haven't done it for a while but it is something like that. I think there is a youtube video that does it like this. I might have the ratios round the wrong way, if so swap the side instructions.
On the mountain bike I wind the pads out so the gap is more than for hydros, and then use the leverage feature of the Avid SD levers so they are still powerful. That is the biggest advantage of mtb BB7s over hydros in my book.
If your BB7s are not good it's all to do with the cables or levers and not the calliper.
Some cable outers are too springy, ie compress too much.
Some people run their cables in too tight curves creating friction.
Most mtb levers are rigid enough, but some road levers have a lot of flex.
Attend to those issues and you'll be happy with the brake performance.
Now mine are bedded in they work pretty well, you can grab enough from the hoods to endo the bike.
This method works fine if you then back off the static pad 2 clicks max and maybe adjust the cable tension. It means the pads are square against the rotor as possible - flexing the rotor as the brake goes on means it's never perfect but wear will adjust for that pretty quick.This meant my (still crap but can get away with it) method of applying the brake with the post mount bolts loose and then nipping them up to get the brake aligned and centred to the rotor was next to useless.
I've been pretty impressed with them - XTR levers, std cables with as straight a route as possible and careful set up, works well. Hauled up a loaded 29er on 180mm rotors F+R off-road in the Alps no problems. 160mm rotors seem to lack initial bite but the power is there for my usual XC stuff.
I found Ashima pads worked better than the stock ones - these [url= http://www.evanscycles.com/products/ashima/disc-pads-semi-metal-avid-juicy-bb7-ec023092 ]BB7 pads[/url] smoother with more bite and power for less lever pressure, not tried any others to compare tho.
A good guide here, if a little patronizing at times;
http://www.twowheelblogs.com/avid-bb7-disc-brake-set-and-tuning
I've got road and mountain ones and have been messing about with them for a while. Found this good for both http://howtosetuptheavidbb7.weebly.com/how-to-set-up-the-avid-bb7.html
There's also a Volagi you tube vid that's ok.
They do take a while to bed in (longer than you think) and definitely need new cables. I think the MTN ones are better than the Road on balance.
Don't think they are that much better than my avid cantis but and a big but, they do still work in conditions where the cantis would have been rendered useless long before.