Can anyone say, how much diameter of rotor(disc) is required for

[Bharath reddy]

can anyone say, how much diameter of rotor(disc) is required for locking of all 4 wheels of a 300kg vehicle in an off road?? (approx.)
and i heard from technicians that drum brakes can`t lock wheels, is it true??

 

[Mech_Engineer]

It depends on how much braking force can be applied to the brake pads. Even drum brakes can lock wheels, although disc brakes tend to provide more stopping power for the same braking force.

 

[DickL]

Drum brakes can lock wheels. Locked-on brake applications (parking brake) tend to be easier to implement with drum brakes than with disc brakes. Being able to lock wheels, with either disc or drum, is primarily a question of effective brake radius, applied brake shoe/pad force, and friction material.

Disc brakes have several advantages over drum brakes, lighter, cool off faster, easier to implement anti-skid control, have a more progressive or linear feel (pedal pressure vs. braking force).

Locking up the wheels, once, is largely a question of how much force is applied to the rotor by the brake pads. Sizing brakes for general use is far more involved than just being able to lock the wheels. Still, determining the force/torque needed to lock the wheels is a question of adhesion, wheel diameter, vehicle weight, rotor or drum diameter, and how much force can be applied to the brakes (how strong is your leg). Typically for maximum braking capability, an adhesion value of 1 is often used.

 

[Ranger Mike]

true..drums can lock up just like disc brakes..the biggest draw back to drums is heat build up and brake fade..the inability of the brake shoes to slow the vehicle due to excessive heat..your atv wight of 600 pound leads me to think a good set of motorcycle brakes would do it..
you will have t o be careful on the master cylinder selection..think about using a brake proportioning valve..maybe run two master cylinders with different diameter bores..after you calculate the front to rear weight bias..ifin you run one master cylinder you may loop the car due to too much front brake bias..additionally a single master cylinder is dangerous..especailly in th e bush where all kinds of jagged things can destroy brake hoses