Master Cylinder Sizes

[jon@harrison.ne]

As a mechanical engineer I appreciate Mikes thorough explanation or brake line mechanics. I would only add that we should be more precise about terms like force and pressure especially regarding units. "Force" has the units of pounds , "pressure" has the units of pounds per square inch, and "torque" is in "inch pounds" or, dividing by 12, foot pounds. Braking is achieved by applying a force to the pedal which then produces a different force (probably larger due to the pedal leverage and balance bar) to the master cylinder piston. This creates a pressure in the brake fluid which in turn creates a force on the wheel cylinder piston. This force results in a torque on the wheel (torque=caliper force X pad coefficient of friction(dimensionless,i.e. no units) X rotor radius.
Also I would like to thank Merv for his kind comments about my slabside Cobra. In light of the recent discussion of JCF it is an example of what can be made from his hardware if you take the time and are concerned with authenticity.

[Aussie Mike]

Originally Posted by jon@harrison.ne

As a mechanical engineer I appreciate Mikes thorough explanation or brake line mechanics. I would only add that we should be more precise about terms like force and pressure especially regarding units. "Force" has the units of pounds , "pressure" has the units of pounds per square inch, and "torque" is in "inch pounds" or, dividing by 12, foot pounds. Braking is achieved by applying a force to the pedal which then produces a different force (probably larger due to the pedal leverage and balance bar) to the master cylinder piston. This creates a pressure in the brake fluid which in turn creates a force on the wheel cylinder piston. This force results in a torque on the wheel (torque=caliper force X pad coefficient of friction(dimensionless,i.e. no units) X rotor radius.

Thanks Jon,

I'm no mechanical engineer, just a layperson. I've no formal training in this stuff but an interest in all things mechnical I've always been fairly good at looking at a system and visuallising how it works. Probably because I pulled everything apart when I was a kid.

I've gone back through my post and fixed up some of my incorrect terms. Hope it makes more sense. most of the time I'm thinking faster than I can type.

Cheers