Re: [CR]50mph cadence

(Example: Framebuilding:Tubing:Columbus:SLX)

From: "Mark Petry" <mpetry@bainbridgeisland.net>
To: "Stockwell, Brad" <BRAD.STOCKWELL@mpp.cpii.com>, <Classicrendezvous@bikelist.org>
References: <9CE7CEBC1555D4118FCD006008279E684C7F42@mppmail.mpp.cpii.com>
Subject: Re: [CR]50mph cadence
Date: Tue, 12 Jun 2001 11:33:46 -0700


Yes but...

If he were on the small (42) ring, and in the smallest rear sprocket, 14t, then the developed gear length would be 21.19 feet (((42/14)X(27X3.14)/12) ...

Yield 207 RPM in a 42/14 to do 50 MPH

markp


----- Original Message -----
From: "Stockwell, Brad"
To: Classicrendezvous@bikelist.org
Sent: Tuesday, June 12, 2001 11:09 AM
Subject: RE: [CR]50mph cadence



>
> "to achieve the 50 mph (much less 60 mph)...a cadence well
> in excess of 300 rpm given any stock rings available at the time"
>
> Actually, with a 53 chainring and an 11 cog, 50mph is
> achieved at 130 rpm (assuming a 68cm diameter wheel, which is 26.8 inch or
> 2.23ft; circumference is then 7ft; 53/11 is a gear ratio of 4.8, so we get
> 33.6 ft/pedal revolution. Then 33.6ft/rev X 130 rev/min = 4368 ft/min =
> 0.83 miles/min = 49.8 mph). This is not surprising since racers often pedal
> down mountain passes at such high speeds.
>
> Brad Stockwell
> Palo Alto