blb@cbscc.UUCP (Ben Branch) (01/15/85)
I am wondering how well the Zzzipper fairing -- makes the front of your bike much more streamlined -- works. They advertise a pretty good percentage of drag reduction, but, is that only for racing or downhills (20+mph)? What about touring at 14-17mph, which is where I'd be using it? Any experiences?
mroddy@enmasse.UUCP (Mark Roddy) (01/16/85)
> > I am wondering how well the Zzzipper fairing -- > What about touring at 14-17mph, It is the best you can do for a standard bicycle, and it's really pretty good despite the fact that it looks stupid. Scientific American ran a really good article about bike aerodynamics two years ago- with all the vital stats- and the zzipper did real well.
josh@topaz.ARPA (J Storrs Hall) (01/17/85)
> > 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