Originally Posted by icemilkcoffee

I bought my son a used MTB to ride to school with. It came with mechanical disc brakes. The front one was really stiff and the stopping power unimpressive. I looked at the caliper carefully and noticed that only one piston and brake pad moves. The other brake pad is stationary. The brake works by bending the disc towards the stationary pad! So a lot of effort is spent bending the disc rather than braking. What a dumb system. Who on earth designed these things? If they wanted the disc to move around, why didn't they adopt the floating discs routinely used on motorcycles?

Anyways, I moved the stationary side as close to the disc as possible to minimize the need to bend the disc. But it took a lot of finagling, and I imagine with brake wear I'd have to do this repeatedly. Is it worthwhile to upgrade to double piston mech calipers? Is there a noticeable difference? Or would the two springs increase effort to the point that it negates whatever theoretical advantage that two moving pistons bring?