Well, to get my shot in at this dead horse;
check any mathematical formula for calculating the distance traveled by
rotation of an object and you will see the one constant in all the formulae
is circumference.
If you know the circumference you don't need to know the radius but if the
circumvented is unknown then it is easier to calculate it using the radius.
The circumference never changes.
Example: use a 1 foot square "wheel" circ.= 4', assuming no slippage 1
rotation of the square "wheel" = 4'. It doesn't matter where the rotational
centre is located.
Now think this tire issue out ! The contact patch of the tire is stationary
relative to the ground and the vehicle is driven forward by torque.
The top of the tire therefore has to travel forward at twice the road speed.
At 75 MPH the top of the tire is traveling at 150 MPH.
Gone for beers now :)
Jim L
 Original Message 
From: "Larry Daniels" <ladaniels@sbcglobal.net>
To: "MG List" <mgs@autox.team.net>; "Spridget List"
<spridgets@autox.team.net>; "David Lieb" <dbl@chicagolandmgclub.com>
Sent: Friday, June 03, 2005 6:20 PM
Subject: Re: As the wheel turns
>  Original Message 
> From: "David Lieb" <dbl@chicagolandmgclub.com>
> Subject: Re: As the wheel turns
>
>
>> If anyone else is willing to duplicate this ...
>
> All I know is that bicycle speedometers want you to mark where the wheel
> touches the ground on both the wheel and the ground, roll it forward with
> your weight on the bike until the mark touches the ground again, mark it
> and
> measure between the marks. Talk about begging the question!
