Max tire width...

[campfire]

How wide a tire can be reasonably put on a given width?
What issues arise from exceeding reasonable tire width?

I have some 8" rims and some 6.5" rims. I get the idea that 12.5" wide tires on my 6.5" rims are a bad idea, but I'm not really sure what happens...

 

[SouthernYank]

I'm going to be running 38x15.5x15 on a 10" wheel, there's plenty of guys running this setup and guys running 44" tires or bigger on 8.5" H1's.

 

[tRustyK5]

I had 39.5 x 15's on 8" rims. I ran 35x12.5's on 6.75" steelies for years with no issues. With enough sidewall it just isn't much of an issue...

 

[campfire]

I had 39.5 x 15's on 8" rims. I ran 35x12.5's on 6.75" steelies for years with no issues. With enough sidewall it just isn't much of an issue...

So...why do folks bother with wider-than-stock rims? Just for wide, short tires?

I''m thinking about 33x10.5 or 33x12.5, as a reference point.

 

[dremu]

So...why do folks bother with wider-than-stock rims? Just for wide, short tires?

I''m thinking about 33x10.5 or 33x12.5, as a reference point.

IIRC, the tire manufacturers specify a range of rim width for any given tire.

For example,

http://www.bfgoodrichtires.com/tire-selector/name/all-terrain-t-a-ko-tires#techspecs

 

[campfire]

IIRC, the tire manufacturers specify a range of rim width for any given tire.

For example,

http://www.bfgoodrichtires.com/tire-selector/name/all-terrain-t-a-ko-tires#techspecs

So...none of those past 245mm (~9.6") are listed as being useable on a stock 6.5" rim. What are the ill effects of exceeding the recommended width? Does it slip off the rim more easily? Or does it just look odd being all squished in toward the center?

 

[drew4x4]

i'm pretty sure it affects the outer most shape of the tire.... which creates an imperfect surface against the rode, affecting your tire wear. (reducing the amount of miles you would get out of a tire)

 

[diesel4me]

Yes,the center of the tread will wear down faster ,the skinny rim squishes the tread inward,makes a crown in the center,much like over inflation will..

However,in my experience I have used tires as wide as 12.50" on stock 6 or 8" rims and didn't really notice them wearing down in the center quickly...the front ones always do anyway on a straight axle 4x4,so its hard to tell if it really did grind them down faster ...you can run a lower pressure to make up for it some also..

Wide tires on skinny rims = poor man's beadlocks!...pretty hard for mud and sticks to get in the beads when the sidewalls are sucked in so much..

 

[rompinstompinmudmonkey]

I run 37 x 12.50 military Goodyear's on stock 6.5" dually rims. I only run the tires at 30 psi and they still crown enough that I only run on the center tread lugs.

 

[6.2Blazer]

My 2500HD had the stock 6.5" wheels and came with 245's. I then installed BFG AT 285's (about 1.6" wider) on the same wheels and had 65,000 miles on them and while getting thin, they were not completely worn out. It currently has a new set of the exact same tires mounted on 8" wheels. There is no obvious difference in ride or handling but can't comment on wear since the truck is no longer a daily driver.

Both myself and a friend run 15.5" wide Swampers on 8" wide rims for the off-road rigs. He has run this combo for years and put several thousand miles on the road up to 65 mph (drove to trails up to 3-4 hours away for years) and it drove really good. Off-road the narrow rims work good. Previously I ran 13" wide Swampers on 10" wide rims (they were not 16.5's either!) and was almost guaranteed to debead a tire if I went below 20 psi. With the 15.5/8" combo I now run down to 7-8 psi and have only popped one bead and my friend runs lower than than and never lost a bead.

 

[campfire]

Thanks, guys! That was just the info I was looking for. Especially 6.2Blazer's post.