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.  

How to make a one piston, mechanical disc brake to work better.

Wheels of Happiness

Rizal Philippines

4.05.2021

This looks outdated and anachoristic now.  And looks unrepairable to some.

Overhauling, mechanical (cable) disc brake.

Wheels of Happiness

Rizal Philippines

4.05.2021

The mechanical disc brake of a kapadyak failed yesterday and I was unable to repair this real quick.  I suspect:   1.  thin brake pad;   2.  loose adjustment of the fixed side;   3.  failed piston   

Hence I need to study this overhaul, so that may be able to find the defect and fix it.  

Just because my bike has hydraulic brake it does not mean I would not know anything about the mechanical disc brake.  

One of our companions was hounded by flats and mechanical trouble in our ride to Manay

Wheels of Happiness

Rizal Philippines.   June  30  2014

                  Idol supervising Engr June as he fixes his flat

One of our fellow Recyclists Engr June had 3 flats plus a skewer that would not lock properly.   But is part of the challenge, and sometimes when you have mechanical problems they come to you in in a bundle (that is to test your mettle and perseverance.)

Boy am I lucky that it did not happen to me.  In one of our rides to Atimonan, I had three flats:   one in Cardona, early on, and two in Cavinti. I would have just preferred to ride in the van.  But I did not.

                           Jerry K had a flat some 5 km form here and he had a chance to have Kysirium wheelset as his repair wheel.