Originally Posted by
big john
Some cable discs only move on one side and the rotor flexes to effect braking. In other words, one pad is fixed and doesn't retract like a hydraulic brake does.
edit: gj beat me to it.
TRP mechanical discs (calipers) are one of the few (if only ?) mechanical disc brake systems that feature two piston movement
they perform better than most of the other mechanical systems (if not all) and are easy to set up and adjust ; 3mm hex adjusts pads in and out
still not as good as a quality hydraulic system - but still fairly good
pic of a TRP Spyre SLC caliper above