wrote in message ups.com...

BB wrote:
snip

There have been lengthy discussions on this; in short, the finding
was
that the width doesn't make that much difference. Seems
counter-intuitive
to me, but that's what they say.

Who is they : )

A web search will reaveal rolling resistance test results.

As BB mentioned, getting rid of the knobs is key. Not all slicks
are created equal though. Some tires of the same size have less
rolling resistance than others. Since you seem interested in this,
find actual test results if you can.

I've had various slicks on MTBs, between 31 and 48mm (1.9"). The
fastest were probably the 31 (although I didn't do side by side testing).
The 48s seemed as fast or faster than the 32mm tires, and the slowest
was a 38mm "slick-like" tire (slick tire with siping grooves) designed for
road-going MTBs. Real slicks are noticeably faster than mostly-slick tires.
I think that's due to the thinner tread layer in the real slick.

If you're gonna do 95% pavement, 5% light dirt, and want to be faster on the road,
buy this tire, from these guys:
http://harriscyclery.net/site/itemdetails.cfm?ID=1320

If you decide to do loose dirt, or serious MTBing, spend a few minutes to put your
knobbies back on.