The Natural Philosopher wrote:

On 06/05/17 18:41, DerbyBorn wrote:

Why don't they make the pads just a bit bigger so that they don't allow a
lip to develop on the periphery of the disc?

cos then they'd put a lip on the pads instead

I am sure you are right. Secondly it would produce an axial force on
the pad, thirdly it would render part of the pad unused. Fourthly, and
I think most importantly, movements of the pad against the edge of the
disc would shatter the outer few millimeters of the pad material (which
has little tensile strength) so you would be back to the bearing surface
of the pad being inside the perimeter of the disc quite quickly.

--

Roger Hayter