Tires: Tire, Rims & Fitment, 18 rims, 17 rims

Question
Hi Barry,

What is the true tire/rim fitment story? I've been told so many different stories, it's time to hear the truth!!
  
Will an 18" tire fit on a 17" rim? What is the biggest size tire that fits a 17" rim, or an 18" rim, a 20" rim, etc.
And the true answer to the width problem? With a 7.5" wide rim what is the widest size to fit that width, and a 8" rime, and a 9" wide rim.

:-)
Thank you!!

Answer
Kim,

Will an 18" tire fit on a 17" rim?

No.  18" tires fit on 18" rims, 17" tires fit on 17" rims, etc.

What is the biggest size tire that fits a 17" rim, or an 18" rim, a 20" rim, etc.

This depends on the width of the rim.

Here's a tire calculator, that among other things, will give you the allowable rim width for a given tire size:

http://www.1010tires.com/TireSizeCalculator.asp

And the true answer to the width problem? With a 7.5" wide rim what is the widest size to fit that width, and a 8" rime, and a 9" wide rim.


There isn't a simple answer as it depends on aspect ratio, but that calculator will aid in that.