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      12-02-2008, 01:09 AM   #41
Major General
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Drives: E30 M3; Expedition
Join Date: Apr 2007
Location: USA

iTrader: (0)

I don't see the need to respond to the details of your last post. And to try to keep things collegial, I won't refer to your language as "rattle", but do go over your posts to see the tone you used in this exchange.

You have once again avoided the issue, the clear question I posed, and actually answered, which is simply: How does the kinetic energy of the vehicle end up in the rotor? How does the rotor experience the temperature change the conservation of energy equation dictates? Through what mechanism exactly?

The question has been answered by a domain expert, a scientist, as well in a well respected peer reviewed journal. The man has written a dissertation and a book on the topic and who knows what else, and you question the validity of his explanation--that one needs to increase conductivity to control friction surface temperatures. You think this explanation would have been published in a peer reviewed journal if it was false? Something as basic as that, simply wrong?

Let's see. Who is more credible here? A well-respected and published scientist, who specializes in this specific area, or Swamp, who has worked on mountain bike brakes for two years (not to discredit your experience in that domain, but that is a different domain, a different ball game).

As to your question, I have already answered it. The ultimate temperature gain of the entire rotor will be governed by the conservation of energy equation (which should also account for whatever energy that is transfered to the environment via convection during braking as well). However, the friction surface temperatures will be dictated by how fast you can transfer the energy that is being generated at the surface elsewhere, which is dictated by the conductive heat transfer principles I've been outlining all along, deltaT (temperature difference between the friction surface and the vented surface of the disc) and conductivity. The temperature distribution throughout the rotor is the key issue here. You want that to be uniform as possible during braking (and it clearly will not be uniform) to achieve the lowest friction surface temperatures.