Brakes Info

[rutthenut]

Spotted a link in the petrolheads.com message forum that gave information on 'warped discs' and other things.

The web site is www.stoptech.com and you may find it interesting or useful. Look at the 'technical' section for whitepapers.

There's even a formula for braking dynamics, at http://www.stoptech.com/whitepapers/formulas%20for%20vehicle%20braking%20dynamics.pdf

All fyi

[Stratos]

Interesting, but is it fundamentally flawed?

They take no account of the size of the Pad Area, therefore according to their formula a pad which is 1sq.cm. would exert the same torque as a pad of 100sq.cm.

Or, do you think they assume that the "Pressure" is "passed" to the rotor regardless of pad size?

In other words, a pressure of 100 at the piston acting on a 1sq.cm. pad exerts 100 on that sq.cm, and a pressure of 100 at the piston acting on a 100sq.cm. pad exerts 1 on each sq.cm. and the friction aplied to the rotor is equal in each case?

[colin artus]

I think that in theory that is correct. However in practice the pad needs to be bigger than the piston(s) and anyway the theoretical 1cmsq pad would vanish in a puff of smoke on fist application,unable to absorb or transfer the heat generated!

Colin

[rutthenut]

Originally posted by Stratos
Interesting, but is it fundamentally flawed?

Not according to the author(s)!

See http://www.stoptech.com/faq/data/faq10.html

One of the white papers, at http://www.stoptech.com/whitepapers/brake_systems_and_upgrade_selections_122701.htm has an explanation on some of the relevant factors.

This includes topics we've discussed before, such as brake pedal leverage ratios (4:1 to 9:1), brake line pressure (800 to 2000psi, for instance), clamping force (based on piston area, not pad area) and braking force (depends on disc radius and co-efficient of friction between pad and disc surface - which is perhaps where pad area comes into it).

Other papers are listed at http://www.stoptech.com/technical/ as well as the two I have linked to so far. All of some interest, even if they may raise scope for discussion or possible disagreement...

There is also an FAQ section on their site at http://www.stoptech.com/faq/ although this is mostly related to their particular offerings.

I see that the white papers at this site include Carrol Smith as one of the authors, who is apparently very knowledgeable in the preparation business - going by the number of authoritative books he has written on the subject.

[chris.richard]

Yes, his Nuts, Bolts, Fasteners and Plumbing is fascinating reading. I really worried about myself when I found myself reading it in bed because I couldn't put it down! What a sad anorak I must have become!:rolleyes:
It's got a lot of useful stuff in it, although it is american and deals with metric hardware more as an afterthought.