In article ,
(Tom Keats) wrote:

In article ,
OliverS writes:

Rolling resistance comes from distortion of the tire and the surface. A
steel wheel on a steel rail has the least rolling resistance.

Knobby tires have significantlly greater rolling resistance than a
smooth tire. Likewise high pressure tires have less rolling resistance
than soft tires. The most important thing is to get a bike that fits.
If it has knobby tires, change them to something smoother. I love
Avocet Cross tires 700x35 for general purpose riding and touring. The
inverted tread has low rolling resistance on a smooth surface, and has
some grip on dirt roads and paths. They are a little bit on the
expensive side though. If you are commuting, you do not want knobbies,
unless you are purposely trying to increase your calorie burn.

Knobbies do make a pleasing 'buzz' on asphalt. Sure, they'll
slow ya down and (heaven forbid) allow other riders to pass ya
sometimes. But if you don't care, it doesn't matter. And there
may be some shortcut scenarios where knobbies come in handy.
Even in urban environs.

But slicks are soo much nicer to ride on! And better cornering grip. And
better wet-pavement grip. I have a set of Tioga City Slickers, which are
pretty cheap, available at MEC, and they even have gumwalls to satisfy
the purists. The tread is a minimalist road pattern.

Even on packed gravel, I would opt for the slicks over knobbies. About
the only urban surface a knobby can traverse that a slick cannot is a
muddy slope long enough that you can't just power through by
accelerating before you hit the hill. That's a pretty rare thing, even
when making shortcuts.

One of the worst thing about knobbies is not being able to
run a sidewall generator on them. They can interfere with
fenders, too, on a commuter bike.

I love knobbies when I'm playing in the mud. But one of my Boxing Day
finds was a nice rear wheel for $15, which will soon hold the slicks for
my mountain bike, causing quick-change happiness for planned urban
stupidity.

--
Ryan Cousineau, http://www.wiredcola.com
Verus de parvis; verus de magnis.