I put road BB7s on my drop bar mountain bike and feel they are a huge upgrade over the early generation hydraulic Avid Ultimates (lol). What I like about them are the two plastic knobs on the inner and outer sides of the calliper that allow you to adjust without tools each pad in and out. On BB7s only one side of the calliper is active and it pushes the rotor towards the other passive side but now there are some new TRP Spyre mechanicals with a cam that squeezes both sides of the calliper together against the rotor. In theory this would cause more even pad wear and you can adjust the pad clearance with cable barrel adjusters. I haven't tried them and I'm not sure that feature makes a big difference but the ability to adjust the pads left and right is absolutely essential on the active/passive calipers. I got fed up with the Avid hydraulics. They were a constant annoyance. Hydros potentially have better modulation but the easy adjustability of the mechanicals make them reliably adequate. Never again will a ride be aborted because the brakes leaked or have bubbles in them.
Last edited by Clem von Jones; 10-15-14 at 10:46 AM.