A quick tire question

[Laplander]

Is anyone running the Mickey 33x21.5x15s on their bucket? If so, did you HAVE to use a 15x15 wheel, or would a 15x14 be able to handle a tire that size? I'd like to get the extra six inches of footprint over the 18.5s that are on it now, but don't want the expense of new rims if I can get by with what are on there now. Thanks.

 

[Mike]

When mounted on a 15" rim the 21.5 (16.6") only has 2.3" more tread width than than the 18.5 (14.3") tire mounted on a 14" rim. Trying to run a tire that wide on a 14" rim is going to lose even more tread width, unless you're only running 6 or 7 PSI air pressure.

With that 14" wheel, you may as well save the ginormous difference in tire prices and stick with the 18.5.

 

[Laplander]

Mike, I appreciate the reply. The local tire shop was of no use when I spoke to them about the problem. To try and get as wide a footprint as possible, how wide of a rim would you suggest? The kid really enjoys the almost cartoonish appearence of the big and littles. Plus the added height, 29 vs. 33, will help in that department.

 

[Mike]

An old rule of thumb for maximum tread width on a tire is to use a rim no less than 2" narrower than the tire. Optimally, rim width would equal tread width. On a drag car, that number can easily vary, depending on whether or not you are using a high-growth tire. People will often run tires on narrower wheels, but when you are looking for maximum contact patch, using a narrow wheel is going to require running extremely low air pressures.