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From: josh@topaz.ARPA (J Storrs Hall)
Newsgroups: net.bicycle
Subject: Re: aerodynamics
Message-ID: <295@topaz.ARPA>
Date: Thu, 17-Jan-85 00:55:20 EST
Article-I.D.: topaz.295
Posted: Thu Jan 17 00:55:20 1985
Date-Received: Sun, 20-Jan-85 05:30:13 EST
References: <4599@cbscc.UUCP> <294@enmasse.UUCP>
Organization: Rutgers Univ., New Brunswick, N.J.
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> 
> 	I am wondering how well the Zzzipper fairing -- 


As someone noted there was a good article in Sci. Am. (Dec 83, p 142)
Here's an extract from its tables:

force -- aerodynamic drag force at 20 mph (in pounds)
hp@20 -- horsepower required to do 20 mph
v@.1hp -- speed on level ground, still air when rider develops
	0.1 horsepower (ie, an all-day touring level of effort)
v@1hp -- a "max effort" speed, same conditions
v up -- speed developing .4 hp up a 5% grade
v down -- coasting down same grade

		force 	hp@20	v@.1hp	v@1hp	v up	v down	
Touring bike	4.4	.295	13.1	31.1	12.2	27.7

Racing bike	3.48	.228	14.7	33.9	13.0	31.2

R.B. w/ zzipper	2.97	.198	15.4	35.7	13.1	33.9

Motor pacing	0	.068	29.4	294.0	12.6	?

Moon bike	0	.009	237.5	2375.0	78.4	?

(the figures take account of rolling frction, about half a pound 
on earth...)

--JoSH