Tires on too narrow a rim?

[UncleChris]

DOes anyone know what the downside is to putting a tire on too narow a rim?

For example, if the recommended rim width is 7.5-8" and you put the tire on a 7" rim, what are the repercussions?

 

[HenryJ]

A couple things come to mind. One would be lateral stability. The may tend to feel mushy in the corners. The second would be even tire wear. They would tend to wear out the center of the tread when operating at street pressures.

There may be some advantages for offroad. Aired down they should deform nicely and perhaps even hold a bead better.

Given the choice of a wheel a little too narrow, or one a little too wide, I would opt for a little narrower wheel.

 

[articulate]

There may be some advantages for offroad. Aired down they should deform nicely and perhaps even hold a bead better.

I understand this is precisely why some people install tires on a narrow wheel.

Somewhat related, I tried to get 285/75r 16 BFG All Terrain tires mounted on a 7" wide wheel. The boys at the shop said BFG wouldn't honor the warranty on the tire since that wheel width wasn't within the recommended range. I have no idea if that's true or not, though.

They claimed that the narrower wheel causes the sidewall to heat up too much, and the tire goes kaboom.

But people have tires mounted on narrower wheels all the time. Que sera, sera.

 

[Willman]

Air pressure is key!!! Make sure to watch how your tire is wearing....I rotate mine every oil change to make sure everything is wearing good. Every other week or so, check the air pressure..it can go down due to the hot or cold conds....

low air pressure = bad gas mileage when you are driving around town etc...!!!!

Here's a great writeup from Scott on norrow tires:

http://www.expeditionswest.com/research/white_papers/tire_selection_rev1.html

 

[Scott Brady]

I would not be concerned with the .5" variance.

It is not uncommon for 12.5" tires to be mounted to 7" wheels. Crowning does become an issue on heavier vehicles, but a moderate weight Tacoma is no problem.

 

[vanguard]

I'm not really a tire expert but I do read on the internet a lot. The standard answer is that the tire will not be flat on the pavement and the center will wear out faster than the sides.

And we all know that if you read it on the internet it must be true. :shakin:

 

[UncleChris]

:elkgrin: It's gotta be true!

Hey thanks for the info guys.