T
Tom Sherman
Guest
[email protected] wrote:
> ...
> To reach 63.5 mph, you need extra power or reduced drag,
> either from a tighter tuck, a steeper grade, a tailwind,
> another vehicle to draft, or a heavier rider....
Other (non UCI legal) alternatives include substantially reducing
frontal area, such as a recumbent with a highly reclined seat and bottom
bracket higher than the seat, or substantially reducing the coefficient
of drag by partially or fully fairing the bicycle.
> Pedalling is generally held to be counter-productive at such
> speeds with ordinary bicycle frames and gearing. At 63.5 mph
> with a 2124mm 700c tire and 53x11 gearing, you must spin up
> to 162 rpm before the chain engages the rear wheel--such
> furious pedalling is likely to add more drag than any useful
> propulsion....
The additional drag can be demonstrated by coasting on a long slope, and
then either pedaling backwards at a normal cadence or pedaling forwards
at a normal cadence in too low of a gear to provide any power to the
drivewheel. I have done this on a short wheelbase recumbent, and noted a
drop in speed on the order of 10%.
--
Tom Sherman – Quad City Area
> ...
> To reach 63.5 mph, you need extra power or reduced drag,
> either from a tighter tuck, a steeper grade, a tailwind,
> another vehicle to draft, or a heavier rider....
Other (non UCI legal) alternatives include substantially reducing
frontal area, such as a recumbent with a highly reclined seat and bottom
bracket higher than the seat, or substantially reducing the coefficient
of drag by partially or fully fairing the bicycle.
> Pedalling is generally held to be counter-productive at such
> speeds with ordinary bicycle frames and gearing. At 63.5 mph
> with a 2124mm 700c tire and 53x11 gearing, you must spin up
> to 162 rpm before the chain engages the rear wheel--such
> furious pedalling is likely to add more drag than any useful
> propulsion....
The additional drag can be demonstrated by coasting on a long slope, and
then either pedaling backwards at a normal cadence or pedaling forwards
at a normal cadence in too low of a gear to provide any power to the
drivewheel. I have done this on a short wheelbase recumbent, and noted a
drop in speed on the order of 10%.
--
Tom Sherman – Quad City Area