Re: [CR] To ride or not - some facts


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From: Tom Dalton <tom_s_dalton@yahoo.com>
Subject: Re: [CR] To ride or not - some facts
To: classicrendezvous@bikelist.org
In-Reply-To: <81.21114eb0.2aae9221@aol.com>
Date: Thu, 12 Sep 2002 10:40:13 -0700 (PDT)

Good point. Moment of inertia has probably not dropped as much as total mass. However, as you pointed out, modern wheels are supporting 9 or 10 cogs instead of 5 to 7. I don't think it is simply a matter of the industry pulling the wool over the consumer's eyes by offering something frivilous but tangible (more gears) at the expense of something important but not obvious (moment of inertia). Naive as I may be, I think rider's benefit from the extra gears (and easy selection) of modern drivetrains and that the current state of affair is a reasonable engineering compromise. I think both consumers and manufactureres of high-end gear should be given a little more credit. Besides, wheels are hardly heavy these days. Even if the sub 1600-gram weight of Ksyriums (a very popular, typical modern wheel) reflects weight savings throughout the wheel, we are talking about a wheelset that is, according to Greg Parker's numbers, significanatly lighter than a 28-hole Ergal! The rims couldn't be that heavy. Tom Dalton Bethlehem, PA Wdgadd@aol.com wrote: In a message dated 9/9/02 5:33:27 PM, GPVB1@cs.com writes:

<< Many wheels today are heavier than many of the wheels of 1982. >>

I've been wondering about this for some time. Has anyone weighed just the rim from a modern "ultralight, climing specialist" prebuilt wheel, such as Mavic Helium? Are they much below 400 gm.? As light as a Fiamme Ergal, Mavic GEL 280, etc.? (I'm REALLY asking; I don't know.) If they are this light, and can deal with the tension of an 8-10 speed dished rear wheel, with reduced spoking, technology has indeed progressed. If, however, since total wheel weight is all that is ever specified, the rim is 400gm or so (as I suspect it might need to be), and all the weight reduction is in the hub and the deleted spokes, it seems to me that there has been a sacrifice of low rotational inertia in favor of more cogs. Remember "an ounce on the wheel is worth two on the frame"? Granted, all this makes not much difference, but are more gears an easier sell?

Best regards,
Wes Gadd
Unionville,CT