[hpv] Big wheel or little wheel, which is better?

[PNGr...@aol.com]

What to add to what has already been said? I think maybe to refer to an
earlier thread on Fat vs Skinny tires and suggest that a large wheel with a
skinny tire can add more than easier gearing options to the make-up of a fast
bike, and that a small relatively fat tire on the front is the right choice
for different reasons. Of course the fact that I ride a Lightning 'may'
influence my thinking, but here goes. It has been stated that the fat tire's
broad contact patch is enclosed by a shorter circumference because a circle
is the shortest line to enclose a given area. This makes it superior in a
turn where the edges of the contact patch scrub. I think this is only part of
the situation. The front tire of any bicycle turns sharper than the rear, and
travels a greater distance than is traveled by the rear due to what I call
the "time share tricycle" effect. That is that the front wheel even when
holding the straightest line, must carve out a sinusoid to each side of the
rear wheel's path to maintain balance. That function is better performed by a
small broad wheel.

The path is straighter for rear wheels, so a large one is able to do its bump
smoothing, energy storing and perhaps flow separating functions without its
long contact patch causing the kind of losses it would were it on the front.
Also, if the front wheel has suspension as does my F-40, then a smaller
lighter wheel will conform to the surface irregularities better and not over
accelerate the main mass of the bike up and down which will leave the rear
wheel less rebound energy to deal with. How's that for a rationalization of
what I already have?

Paul Gracey