On 16-11-17 14:43, AMuzi wrote:
On 11/16/2017 12:47 AM, Tosspot wrote:
Why do they have holes in them?

Car discs don't, motorbike discs don't, aircraft discs
don't.* Why do bicycle discs have them?

Many do have slots or holes. Typical low-end auto discs have a center air
channel. Our researcher discovered this by completely ignoring normal
maintenance:

http://www.yellowjersey.org/photosfr...t/NRCTDISC.JPG


As a maybe related question: Why do bike discs allow for so little wear? The
Shimano Ice-Tech discs are 1.8 mm thick, and need to replaced when they wear
to 1.5 mm. Would there be an issue with cooling if they were thicker? Or, in
the worst case, is this just a way for Shimano to sell more replacements?

Ned

The thinner, the lighter. Thicker discs do not cool worse as heat
dissipated is the same as the surface area.
And replacement rate goes up.