Posted by David on September 27, 1998 at 21:56:07:
In Reply to: A question for the pro's posted by andy on September 27, 1998 at 11:55:38:
Yes / no and yes.
The answer to your first question is the yes and no. There is a calculation for tire width and wheel application but I doubght anyone, including your request for the "pro's" will be able to provide it to you. At the highest level a formula exists, but for all practcal purposes, including tire manufactuers, the reference material put out by the three dominant governing bodies(E.T.R.T.O. , J.A.P.M.A. , T.R.A ) for optimal and approved rim width fitments is what is adhered to. Optimal is sometimes listed as measured ( meaning the width of the wheel used to mount the tire when measuring all the other specs) and approved is the acceptable variations (different wheel width's) that a given tire can be properly mounted on.
The section width and aspect ratio(sidewall height) are definately part of the equation to calculate what width rim a tire will fit on and perform properly. Some of the factors that determine what properly are: load capacity, traction = contact patch & shape, wear characteristics and appearance.
Go by what ever the tire manufactuer lists for a given size tire