Rotor disc bending when the brake lever is actuated?

Wheels of Happiness

Rizal Philippines

7.12.2021

Somebody inquired in a gc why the disc rotor bends when the brake lever is actuated?

This is most likely to occur in mechanical disc brake because only one of the calipers move I think on the right side.  The piston bumps the rotor on one side and the other non drive side is non moving.   So the rotor moves.  It moves less when the disc is centered. 

It does not happen in a hydraulic brake set up.  Because both of the piston move evenly and is self adjusting.   It is scary to see the disc bending as you brake.   Most disfiguremenet of disc occur in mechanical brakes.

Sometime the disc warp because 1.  After hard use/braking somebody poured water on it.  The uneven cooling of hot disc will cause it to warp.   2.  Or wrong tightening.  It has to be tightened in star pattern.  As I found.