Regarding the lighter wheel set being easier to accelerate, I once had an engineering professor explain to me that because every pedal stroke accelerates and decelerates, you continually reap the benefits of lighter wheels. To my "dumb look", he explained that as your foot goes over the top and changes direction from up to down, it is in effect coasting and slowing down, and speeds up and your leg drives down through the power stroke. It's not noticeable on the flats, he said, but compare light wheels to heavy wheels on a steep climb when you're pedaling a slow cadence. I certainly noticed a much livelier feel when I climbed our local "bad hill" on my first set of tubulars. Likewise when I swap between my "touring wheels" and the "racy wheels" on the Marinnoni. Much more so than just throwing half the tools out of the saddle bag for equivalent weight savings.
Regarding "old" vs "new" debates, I've found all sorts of kids interested in vintage stuff when it's explained to them as "historic", but still valid riding gear. Start off by admiring their welded techno gee whiz ride, and soon they'll be asking you what those funny sleeves on the end of your frame tubes are. One young lovely asked me what kind of titanium Reynolds 531 was. You can explain that while Ergo is great for racing and power shifting in sprints, friction is more reliable, less maintenance and usually lighter. Neither is "better" or "the only right answer". You can usually segue into who Eddy Merckx was, and how beautiful the old bikes are. I ended up selling an early 80's Colnago with Suntour Superbe Pro to my local tattooed, young flat belly wrench, Jeremy Haynes of this list. Jer races modern stuff, but loves the old stuff too. Just let the beauty of the classics sell themselves. Anyone who rides will dig em.
Tom Adams, Kansas City
-----Original Message----- From: Charles T. Young <youngc@netreach.net> To: classicrendezvous@bikelist.org <classicrendezvous@bikelist.org> Date: Saturday, April 21, 2001 7:04 AM Subject: Re: [CR]Re: Reducing the "Polar Moment of Inertia"
>I recall once having seen a statement that removing a gram of weight from
>the wheel (not specified whether from the rim/hub/other) was the equivalent
>of removing 2.3 grams from the frame (or other non-rotational components).
>Anybody recall that tidbit? Seems a little to "precise" a value to have
>arisen from a guess.
>
>Charlie Young
>Honeybrook, PA
>
>
>-----Original Message-----
>From: RMAugust@aol.com <RMAugust@aol.com>
>To: classicrendezvous@bikelist.org <classicrendezvous@bikelist.org>
>Date: Friday, April 20, 2001 6:56 PM
>Subject: [CR]Re: Reducing the "Polar Moment of Inertia"
>
>
>
>
><< Why doesn't someone offer some proof that weight matters all that much
to
>begin with and that rim and tire weight matters more. All I see are
>unsubstantiated claims. I say until some one can prove different rotating
>weight doesn't matter more, and that weight in general doesn't matter all
>that much.
> >>
>Given two wheels of equal weight, one with a greater proportion of its
>weight
>in its rim and tire will have a greater polar moment of inertia which
>therefore will accelerate at a slower rate of speed. A good example of this
>is an ice skater rotating with arms extended (high polar moment) and then
>moving the arms in very close to the body (lower polar moment). The result
>is
>that the speed of rotation increases dramatically.
>
>Wind resistance plays a small role in this but mainly it's the reduction of
>the polar moment. In the case of wheels, reducing the polar moment makes a
>bike feel more fleet and in competition can give one an actual speed
>advantage off the line. That's the proof of why reducing rim and tire
weight
>matters more than reducing weight in general.
>
>As to reducing weight in general, I think it's generally known that, given
>no
>other variables, a lighter bike will be more efficient to move owing to
fact
>that less calories are required to fuel it.
>
>Randy
>Corral De Tierra, Ca.