On 12/18/2017 7:55 AM, Emanuel Berg wrote:
Another issue is - when does chain wear occur?
Is it when pedalling forward or is it when
starting and stopping, including the
foot/coaster brake?

Here we assume "normal" usage

It's reasonable to assume that wear is proportional to the product of
contact pressure and velocity.

That would mean that stopping with a coaster brake would cause almost no
wear on the chain. You need motion between the parts in contact to have
wear.

If you're starting from a stop by applying extra torque to the cranks
(as is usual) you would get extra wear at that moment. But it's only
for a moment. I suspect it has little overall effect.


--
- Frank Krygowski