[Spridgets] Bentley-RR Trivia: was calculating speed

[Kitterer Bob]

Going from 10 to 20 inch wheels at the same rpm will be three times  
as fast  not twice - C= pi D  :-0

Bob Kitterer

1960 Austin Healey Sprite (Mk IV in disguise)
1966 Austin Healey Sprite Mk III (Trevor) - still in boxes
2000 Miata Special Edition




On Oct 21, 2008, at 11:58 AM, Lester wrote:

> For example a 20 hp bike motor that will turn 6000 revs (and  
> pretending that the tranny is direct drive) will turn the tires  
> 6000 revs.  If those are 10 inch circumference tires then the bike  
> will go speed x,(no, I'm not going to calculate it out.) but if you  
> have 20 inch circumference tires then the bike will go twice as  
> fast *** IF *** it is not limited by drag and that the engine can  
> turn the 20 inch circumference tires at 6000 revs.