Date:         Thu, 17 Apr 2003 18:03:24 -0400
Reply-To:     Kim Brennan <kimbrennan@MAC.COM>
Sender:       Vanagon Mailing List <vanagon@gerry.vanagon.com>
From:         Kim Brennan <kimbrennan@MAC.COM>
Subject:      Re: Tires
Comments: To: John Rodgers <j_rodgers@CHARTER.NET>
In-Reply-To:  <3E9EA2A7.1020305@charter.net>
Content-Type: text/plain; charset=US-ASCII; format=flowed

Not entirely. There are two factors to consider. Rolling diameter
(determined by the tire) and weight.

The weight matters because it takes more energy (read power) to spin a
heavier wheel/tire than a lighter wheel/tire. AND, WHERE that weight is
distributed makes a difference. Weight at the outer circumference takes
more energy to spin  (or stop) than weight concentrated at the hub.

When you go to a larger wheel you usually are adding additional weight
to the wheel/tire, but you are also changing the weight distribution,
usually by moving more of the weight away from the inner hub.

This all affects acceleration times. A longer circumference is harder
to spin, and a heavier circumference (even at the same size) is harder
to spin.

I certainly noticed it going from steel 14" wheels (205/70R14 tires) to
alloy 15" wheels (215/75R15 tires).


On Thursday, April 17, 2003, at 08:48  AM, John Rodgers wrote:

> I haven't actually driven on any 15 inch rims yet, but all my reading
> on
> the subject indicates little significant change. It't going to depend
> largely on the 15 inch tire actually selected.