Having just read this: Park guide on avid mechanicals I'm a little confused about part of it.
The way I set up mechanical discs is so that the bite point is set by the position of the caliper relative to the rotor and fine adjustment by using the cable tension, with the fixed piston as close as you can get to the rotor without a rub.
This setup means that you pull the lever and the rotor doesn't need to bend quite as far = positive feeling brake with minimal sponge.
The avid guidance suggests using a gap between the rotor and the fixed piston should be twice that of the moving piston, thereby causing more flex of the rotor than my setup.
Whenever I've seen them setup the way avid suggest, the overall power is the same, but the modulation is a bit vague and can feel slightly spongy, but not spongy..kinda like the brake is engaged, but not biting much at all, which I suppose is what you may expect?
So, can someone explain the why they should be setup to allow such a large gap? is i rotor clearance 'just in case' or something else?