Disc Brake Laboratory

Read the lesson

Rolling: The car rolls with the pedal up. The pads sit a hair away from the disc, so the wheel turns freely.

Rolling

Speed
Pressure
Clamp
Decel.
Heat made
Disc

illustrative values

DryWetIce

ABS

Pedal force120 N

Speed80 km/h

0%Speed

Press the brake pedal — to doHold the pedal and watch the pads close.
Brake on a wet or icy road — to doChange the surface and compare the stop.
Switch ABS off — to doSee what happens when a wheel locks.
Select a part — to doTry the caliper or the disc.

Now · Rolling

Rolling with the pads at rest

The car is rolling and the disc spins with the wheel. The pads sit a hair away from the disc, so nothing rubs and the wheel turns freely.

This stop

Stop time: 3.58 s
Distance: 41 m
Peak decel.: 0.66 g
Disc rise: +29 K

The brakes stay within the tyre’s grip, so the wheel keeps rolling and ABS never acts.

Live state
Wheel
ABS valvesconceptual
Master cylinder
Caliper
Heat in brakedisc and pads
Heat in tyresliding on the road

Illustrative teaching model of one front corner of a 1,600 kg car — not data for any real vehicle. ABS is a conceptual hold / release / reapply cycle, not a vehicle-dynamics model. Fluid and disc colours are a conceptual pressure and heat map (a real disc only glows above about 500 °C), pad clearance is exaggerated, and the event plays slowed down or sped up to fit the timeline.