Subject: Re: The weight question...
Date: 26 Mar 2000 02:30:27 GMT
Andre Charlebois writes:
> The most important weight is that which is at the periphery of a
> rotating mass. In other words, pedals, rims, tires, tubes are more
> important than cogs, BB's, hubs, etc.
This is an age old fable in bicycling and useful to cite when an
excuse for some new wheels is needed. If they are aerodynamic, then
that's easy to justify even though they are heavier, but just a bit
lighter ones are less so, so out comes the rotational inertia bit.
Inertia is important for acceleration but not at constant speed where
it is probably beneficial, although I don't know of any study that has
quantified this. Francesco Moser used a large flywheel rear wheel in
his last attempt at increasing his Hour Record but the flesh wouldn't
respond. I am sure they analyzed the effects however.
Although it may seem daunting, when another rider pulls away on a hill
or in a bike race on the flat, these accelerations, except in standing
starts, are so small as to make the rotating mass story a hoax. Sure,
the mass counts twice as much when accelerating but two times zero is
still zero, and how long does a rider accelerate. Weight of bicycle
components for climbing is the main consideration, not acceleration.
The rotating mass story is a fable that sounds good and has just
enough technical truth to be one that will probably sustain itself
indefinitely. Making equipment choices by it are a matter of faith,
Jobst Brandt <email@example.com>