Ted Bennett said:Radial tires have for good reasons, taken over the automotive tire industry. (Radial cords allow
less squirm of the contact patch, with an attendant reduction in hysteresis losses and better
steering.)
Quoted message said:With a single track, leaning vehicle such as a bicycle or motorcycle the increased patch stability
probably has less effect on steering, but radial tires would allow for some reduction of wear and
rolling resistance, both issues for bicyclists.
Quoted message said:Why have radial tires not been offered to us? I see that many motorcycles have them these days,
particularly on high performance models. That must mean something to the designers, not just the
marketers.
Radial tires reduced rolling resistance for cars both through eliminating inter-ply shear almost
entirely and thereby reducing tread scrub that was so markedly apparent if you pushed a car on a
shiny slick garage floor. The bias ply would squeal and the radial just rolled... effortlessly.
Bicycle tires don't experience either of these effects to any large degree but one thing they have
is a blow-off pressure that is greatly stabilized by constriction of the bias ply with increased
pressure. I haven't seen any data but I suspect a radial that is otherwise identical to a 45 degree
bias ply tire would blow off a rim dangerously sooner.
Jobst Brandt [email hidden] Palo Alto CA
