13-12-2021, 12:07 PM
My understanding is:
Linings have a co-efficient of friction which varies depending on material composition used. Also brake drum material has an affect. Cast iron in general being better than pressed steel.
This changes with heat, hence the fall off in performance we call fade when brakes are heavily used.
Mechanical gain achieved from our foot to the shoes multiplies the pressure the shoes exert on the drums. The pressure is distributed accross the area of the shoe linings. The smaller the area the higher the pressure per sq. inch and conversely the larger the area the smaller the pressure per sq. inch for the same foot input effort.
So larger area shoes do not increase breaking effort for the same input they just dont heat up so much due to their greater area all other tings being equal. The obvious advantage is reduced fade though.
Hope this helps.
Linings have a co-efficient of friction which varies depending on material composition used. Also brake drum material has an affect. Cast iron in general being better than pressed steel.
This changes with heat, hence the fall off in performance we call fade when brakes are heavily used.
Mechanical gain achieved from our foot to the shoes multiplies the pressure the shoes exert on the drums. The pressure is distributed accross the area of the shoe linings. The smaller the area the higher the pressure per sq. inch and conversely the larger the area the smaller the pressure per sq. inch for the same foot input effort.
So larger area shoes do not increase breaking effort for the same input they just dont heat up so much due to their greater area all other tings being equal. The obvious advantage is reduced fade though.
Hope this helps.