What is Best Way to adjust mechanical disc brakes?

[Cindy]

Anyone in techno land care to answer this?

[bdee]

Which brakes??

[Slider]

Avid's are simple, and there are actually a couple of processes involved. When first setting them up, leave the caliper mounting bolts loose, grab a handful of lever, which aligns them, and tighten the mounting bolts.

On the trail, you can use the lever adjusters, but that only moves the outer pad closer to the rotor, so it is for on-the-fly adjustments only. When you stop, center them by using the star nut adjuster on the inboard side of the caliper. Looking down from the top, turn the star nut to move the inboard pad in so it is the same distance from the rotor as the outside one.

Spin the wheel to make sure it isn't binding.

Slider

[tozovr]

Here's the ULTIMATE BB7 Setup...

this is worth it's weight in hallertau hops...

I've set up a bunch of BB7s using the Park Tool book and a bunch this way...this way is FAR better. I got it from some derelict on MTBR.

I've added my notes along the way...


1) start with clean or new pads. clean the rotors with alchohal and never touch with skin.
1a) rotors must be true to within .005" on a dial caliper or damn close to it.
1b) you must have avid speed dial levers for this to work. shimanos with inner adjusters are close but will never do the job as well. ever. get it? never! and yeah, i forgot 1a and 1b in the beginnin and wasnt about to re # the whole damn thing for the likes of you. so friggin get over it. Really the Shimano 3 position doesn't suck...used it twice with decent results...
2) use locktite on all older caliper and rotor mount bolts, perferably blue 242.
3) loosen caliper adapter bolts slightly and rotate up in the direction of rotors rotation and tighten. 80 ip for you torque fans.
4) loosen caliper mount bolts slightly so caliper can move side to side.
5) back out red pad adjusters fully.
6) turn inner pad adjuster in fully then back out 10 indexed clicks. (at this point, it is a great idea to put a few drops of pro Gold on the threads of the adjuster...you can see them. This will save blisters down the road.
7) turn outer pad adjuster in till it bottoms out on rotor. do not force this step. rotor should not move in caliper at this time but caliper may move slightly on its adapter.
8) tighten caliper mount bolts. 80 ip if ya like.
9) with a cable in yer lever and housing run to the caliper (all new or in good shape and at proper length ill assume) turn barrel adjuster in full.
10) if yer caliper has some miles on it, it might be nice to dab the cable pinch bolt with some wet chain lube, grease or anti sieze.
11) use a 4th hand tool to take up any slack in the cable and tighten the pinch bolt. 80 ip, see a pattern here? as in step 7, do not force this. if ya see movement in the acctuator arm, go back to step 5. I use Channel Locks because I'm Booty-Fab.
12) grab a handfull of lever and check for cable slack. there should be none. if this is a new cable/housing install, give it 4 hard pulls to seat and stretch everything into opperational position then go back to step 11.
13) back both pad adjusters out fully.
14) turn inner pad adjuster in about 4 indexed clicks, pull lever 3 times, spin wheel and check for rub. repeat this step till any rub is heard. once rub is home, back it out 1 click at a time till it goes away then 2 or 3 more for clearence. i go 3 most times.
15) repeat step 14 for the outer pad adjuster. with a ear close to the rotor, not that close dummy!, you should hear zero rub of rotor to pads.
16) lever throw should suit yer style. too tight? back out the outer pad adjuster 1 click at a time till feel is reached, not the inner pad.
17) now that both brakes are set and workin, see how 1 lever feels nice n stiff and the other feels like ass? no probs! thats just a good short front cable vs that long rear cable and all its housing compression. rectify this and modulation feel 1/2 turn at a time of the speed dial knob on yer levers. start with the front knob turned in to soften up the leverage ratio of said cable to match the rears feel. a 1/2 turn goes a long way so take yer time.
17a) see that little allen head on the back of the actuater arm? thats a preload adjuster for the spring tension on the caliper. turn it in to suit additional lever feel. i like mine tight baby! thanx to cuthroat for the memory check!
18 ) i like to trim my cable to about 2" so i can service and re-tune the system several times before replacement is needed. make damn sure it doesnt touch or get in the rotor and dont forget yer cable end (personally I prefer a few drops of Super Glue up the lst inch of cable...no fray...Zac is nutty and like to solder his....
19) take up slack in pad wear by repeating these steps.
20) now go ride and dig yer new brake feel!

An aside, I've run this system with Plain bulk cable from the shop, with jagwire stuff and with Full metal Jackets from Avid...the FMJ does kick some ass, but it looks goofy...the Flak Jacket setup does nearly a good a job.

When I got my Bianchi 29er in, I set it all up using the above specs, as usual, the improvement was fantastic, but the icing on the cake was the cable housings. These were the housings that came on the bike (now 4 months old). I swung by Bergers and grabbed two new cables from Troy and a tiny pensize needle applicator of ProGold. I pulled the old cables, leaving the housings in their respective spots...I then inserted the needle applicator into the housing at the lever and and squeezed a bit into the housing...you can put your mouth on the cable to blow the stuff out the other end, but it's not necc. Feed the old cable in and use the channel locks, 4'th hand tool to tighten the cable. Repeat for the rear brake. The difference in the Newly lubed cable and the old was dramatic (you know me, I like my drama....Evan, your mom called, she's leaving your dad...)

At the end of the day, a nice cable system that is sealed is a good addition for the mucky muck of New England, but if you spend a few minutes a month maintaining your plain stuff, you can still have siiiiiiick brakes.

BB7s rock.

[tozovr]

Avid's are simple, and there are actually a couple of processes involved. When first setting them up, leave the caliper mounting bolts loose, grab a handful of lever, which aligns them, and tighten the mounting bolts.

On the trail, you can use the lever adjusters, but that only moves the outer pad closer to the rotor, so it is for on-the-fly adjustments only. When you stop, center them by using the star nut adjuster on the inboard side of the caliper. Looking down from the top, turn the star nut to move the inboard pad in so it is the same distance from the rotor as the outside one.

Spin the wheel to make sure it isn't binding.

Slider

you don't actually want to center the caliper on the rim as only one pad moves with the Avids and the ratio of clicks is different (2:1) from inner to outer.