Question about White Industries MTB hubs

Discussion in 'Cycling Equipment' started by Keith Beck, Jul 27, 2004.

  1. Tom Sherman

    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
     


  2. [email protected] wrote in message
    <[email protected]>...
    >
    >Plugging in -0.10 for the grade, 0 watts for no pedalling,
    >and 0.950 for air density around 2600 meters produces a
    >terminal speed for the other defaults such as 165 lbs of
    >riders and bike of 24.4 meters per second, or 54.5 mph


    pedalling 180rpm+(3 revs / second) hands together, chin on bars, knees
    together with feet level, aero brake levers, aero pedals, aero rims aero
    chainset 20mm section tyres +light tailwind <10mph
    Apart from corners, never considered coasting down a hill back then. Brake
    or power.

    >
    >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.
    >
    >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.
    >
    >For example, a 102 kg bike and rider (214 pounds), will
    >coast up to 63.5 mph on the hypothetical 10% grade with the
    >0.950 air density.
    >
    >Or the default 165 lb rider could simply tilt the road to a
    >grade of 13.4% at that altitude.
    >
    >As an overweight Shetland pony, if not a modest Clydesdale,
    >even I could presumably roll my 110 kg carcass and bicycle
    >down your 10% grade at 66 mph (assuming that it's nice and
    >straight and uncrowded and long enough), so your
    >high-altitude claim of 63.5 mph seems quite plausible.
    >
    >Drop it down to sea level air density and my 66 mph drops to
    >58 mph.
    >
    >It should be remembered that many high speed claims may be
    >made quite honestly by riders unaware of handsome tail winds
    >or the advantage of 40 pounds of baggage. My best speed
    >coasting down my daily hill is 15 mph higher than usual, a
    >tribute to a fine west wind, while my regular victories over
    >a friend in coasting contests down the same hill rely on my
    >extra fifteen pounds of ballast, much like any underhanded
    >soapbox derby triumph.
    >
    >Carl Fogel
     
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