about Disc brake

complicated said:

Hi,
Do anyone can explain forces that work on discbrake when it's working? Or are there any sites that explain it?

Thank u for your help

Hydraulics rely on a small piston pushing on a larger piston creating more force (think surface area and force - a pin will penitrate your skin with minimal force?)
The smaller the piston the more power, but the smaller the piston the less pad movement. A disc can be manufactured more precisely, which means the pad can sit a lot closer to the braking surface without drag.

Discs also benefit from being more compact - theres no flex taking power away, rim brakes flex at the stays, rim and cables.

Everyone should be aware of the forces a disc brake creates on your front wheel. Because it sits below and behind the front axle, the force of breaking is effectivly pulling the wheel from its dropouts, ALWAYS make sure your QR is super tight an stay well clear of titanium QR's these stretch a lot - A guy broke his neck and died recently because of this problem.

budgetbikes said:

Hydraulics rely on a small piston pushing on a larger piston creating more force (think surface area and force - a pin will penitrate your skin with minimal force?)
The smaller the piston the more power, but the smaller the piston the less pad movement. A disc can be manufactured more precisely, which means the pad can sit a lot closer to the braking surface without drag.

Discs also benefit from being more compact - theres no flex taking power away, rim brakes flex at the stays, rim and cables.

Everyone should be aware of the forces a disc brake creates on your front wheel. Because it sits below and behind the front axle, the force of breaking is effectivly pulling the wheel from its dropouts, ALWAYS make sure your QR is super tight an stay well clear of titanium QR's these stretch a lot - A guy broke his neck and died recently because of this problem.

that's hydraulic disc brake. and how about mechanical one?

Well, because the pads are close to the disc - you can use a lever which pulls less cable - less cable = more force