John Forrest Tomlinson wrote:

Chalo wrote:

The faster you ride, the more you need in terms of rim protection,
shock absorption, wear resistance, pinch flat resistance, and
traction. So the faster you go, the more you can benefit from a wider
tire.

I can see that for traction, though very few people go near the limits
of traction on moderatley narrow tires.

But why dod you need more for rim protection when going fast? Or
shock absorbtion? Or wear resistance?

Because the energy contained in bumps goes up as the square of the
speed. It's four times easier to pinch flat or flat spot a rim at
30mph than at 15mph.

And more to the point, do people trying to go fast care about a little
extra shock absorbtion?

Why wouldn't they? Every watt of muscle power they spend absorbing
bumps is a watt that doesn't make them go any faster.

http://www.canosoarus.com/08LSRbicycle/LSR%20Bike01.htm
http://davesbikeblog.squarespace.com...ge/Speed04.jpg
http://www.fredrompelberg.com/upload...cord_fiets.JPG

These are bikes which went very fast indeed, for which rolling
resistance was a primary limiting factor in the speeds they reached,
and which used both fat tires and front suspension even though they
rode on one of the smoothest, least blemished surfaces available
anywhere.

And Chalo - I have a couple friends who weigh 100-105 lbs. In your
scheme of things, are they allowed to ride 23s or woudl you tell them
they'd be better off riding 25s or larger? Not knowing them or their
riding goals.

If they ride on the streets I ride on, the smallest I could recommend
is 28mm. That's what my wife uses, and she rides about as slowly and
sedately as any able-bodied person could. For much smoother and
better maintained streets, perhaps a narrower tire would be
acceptable.

Chalo