For the 12.5" wide tires, do I need a 16"x8" or a 16"x10" rim? thanks everyone!!

 

It'll fit either 10s can fit those huge tires though. I use 17x8 on my 12.5

 

Hey thanks. Would there be an issue with breaking the bead easier on the skinnier rims?

 

I have not had any problems nor have I heard anyone else either but anything is possible I guess. I wish I had gotten 9s just so I could move to 13.5 without worry.

 

You would be more likely to break the bead with the wider wheel

 

wider wheel is better for street but dangerous to air down. If you never have a need to air down, i would go with the 10" wheel b/c you can run higher pressure in them and still keep the whole tread on the road b/c you have less ballooning in your sidewall. if you ever want to play off the pavement, then go w/ the 8" wheel b/c 15 psi is really nice on the trail.

 

Every tire has wheel width specifications from the manufacturer. Once you select a tire, look up the approved wheel widths.

Most 35x12.50 in 15, 17 & 18 require between 8.5" and 11" to meet factory approval.

I'm not sure about 16s. They don't seem to be as common as 15", 17", 18" and 20".

In fact, 16.5" tires (Hummer/military) are probably more common than 16s.

 

That's fine for your grocery getter but "approved widths" are a recipe for loosing beads offroad, all day long. The narrower wheel is going to be better aired down, keeping more pressure on the bead to stay sealed.

The down side is that tends to pull the corners of the tires up when using the high end of the street pressure spectrum, which tends to wear the center of the tire and doesn't give you the best outside tread contact. The solution to that is to run the chalk test and see exactly what pressure your tires want to be at, for your specific vehicle, which everyone should be doing anyway.

 

Yes, you can run non-approved configurations if you are will to forego manufacturer warranty and legal liability when something goes wrong.

As far as airing-down, it might seem like a narrower wheel with wide tire creates greater bead force and I'm sure that's true on an unloaded tire but with vehicle weight you might find the bead contact angle is increased reducing the contact surface area between tire and wheel.

Some think 12.5 tires are too wide for the trail (maybe an inch too wide for typical JK loaded with gear). But they look so impressive when parked at the grocer.

"The Impact of Tire Width on Traction"
Expeditions West: Tire Selection for Expedition Travel

 

I use 17x9 on mine.