Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Posting-Version: version B 2.10.2 9/18/84; site topaz.ARPA Path: utzoo!watmath!clyde!burl!ulysses!allegra!bellcore!decvax!genrad!mit-eddie!godot!harvard!seismo!topaz!josh 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. Lines: 30 > > 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