Last year I gave up on hydros after years of banging my head against the wall with the likes of Hayes hydros, Avid Elixirs, and Shimano offerings all failing me repeatedly. I decided that I wanted to keep it simple and cheap but have good braking power and modulation with solid feeling engagement.
Enter the Avid BB7. Best mechanical disc brake on the market. It works great and is cheap. They work great out of the box but there are a few tweaks I've found that take it to the next level.
Here is The Bric's guide to hacking the BB7.
Cables matter! Get yourself a good set of compressionless cables. The quality of these make all the difference. I chose Goodridge cables and housings for this job, they work great, but get out your wallet, they are not cheap.
Lever madness. Levers make a big difference as well. If you are trying to keep it cheap as possible, use the Avid FR5 levers. They can be bought for $15 online and work great with the BB7. If you want a little more feel and adjustment out of your brakes, use the Avid SD7 Speed Dial levers. They have an unreal amount of adjustments at the lever and will give you nearly hydraulic feel at the levers.
Rotors. Use Avid rotors, I've found that the G2 work best with the BB7. The Heat Shedding rotors work second best.
Lets put it all together now.
The proper install. When you install the BB7 caliper be sure to have it centered perfectly. I turn the pad adjusters (red dials on each side) in evenly so the rotor sits dead center in the caliper. Tighten down the bolts and turn the dials out a few clicks each for now. Everything should look perfectly lined up.
Install your levers at your desired angle and adjust the lever reach to your preference. Install cables, be sure to use a file and flatten out the cable ends after cutting before you put on your housing cap (this DOES make a difference).
Use the barrel adjuster on your lever only to take up any slack in the cable. Do not adjust it enough that it pulls the BB7 lever arm as this will take away from the amount of modulation the BB7 has.
Adjust the engagement point of your brakes using the red dial adjusters on the caliper. Be sure that there is no rubbing when the wheel turns but you still have about an inch of space from the lever to the grip with a firm hold on the brakes. I find that having the inboard pad adjusted a little further away from the rotor than the outboard pad gives a bit more modulation at the beginning of the brake engagement.
There is a small set screw in the caliper body that tensions the caliper return spring. Take that bitch out and toss it. With good cables and housings, and a good setup, you don't need all that tension for the caliper to return. This will make your lever action very light and you will have more feel at the lever.
Now go ride, bed the brakes in by riding some extended downhills while dragging the brakes then periods of cooling. I've found that the brakes come alive after 3-4 rides, any subsequent pad replacement requires this bed in procedure again. Now go out and enjoy the most reliable brakes you could ever ask for.
The Bric...._ mountain biker, road rider, heavyweight gear abuser. Built like a brick sh*thouse. No bike is safe.