Hey everyone,
I keep getting different views regarding putting 31's on my stock rim. Some tire places tell me that you get a better footprint from a 30x9.5 tire on 15x7 rim while some other places tell me that 31's will be to wide on a 15x7 rim which could place some stress on the sidewalls.
Any input or suggestions on what size will be best?

 

[updated:LAST EDITED ON 06-Nov-02 AT 07:39 PM (EST)]Just using www.ntwonline.com as a reference, BF recomends a 7" rim for a 9.5 and a 8" rim for a 10.5 tire.

 

it will work fine

 

I forgot to mention that is a 2x4, 1990 F150

 

Agreed, my truck has had 31s on 15x7s for many many years with no problems.

 

I'd say yes and no. I have mounted 31's on Isuzu 15x6" rims before with no probs, but it looked goofy. 8" is the best size, but a 7 will work. The only thing is, the handling difference between a 7 and 8 inch rim. That wide of a tire on a 7" rim will try to roll of, causing understeer, and a wallowy ride, and possibly more bump steer.

Jared

 

You should be fine...

 

I'm putting 31x10.5's on my stock 15x7 rims on an 89'f150 tonight and everyone i talked to around town said they'd work great.give more surface area on road better traction little more clearance for winter.we tried one to see if it would fit in the wheel well and they did the only problem is a little rub when cranked all the way to the right. Ill put them on tonight and get back with ya in morning :-X12

'86 F250 302
'89 F150 300 soon to have 31x10.5 firestones :+

 

Thanks for all the advise guys!

 

I also have 31X10.5 tires mounted on 7 inch rims. (the 1994 chrome Ford wheels)

They work perfectly fine, they rub a little when you have the steering at full turn in reverse.

Josh

 

Sam's wouldn't even mount them, their book said it was not recommended so i went with the 30x9.5's I like them, but they aren't much bigger than the p235's that came off.......but they look good check out my gallery, with the darker pics......they are the one's with my new BFG's

 

Actually, after looking i don't have any pics of my new tires here lol.

 

>I'd say yes and no. I have mounted 31's on Isuzu 15x6" rims
>before with no probs, but it looked goofy. 8" is the best
>size, but a 7 will work. The only thing is, the handling
>difference between a 7 and 8 inch rim. That wide of a tire
>on a 7" rim will try to roll of, causing understeer, and a
>wallowy ride, and possibly more bump steer.
>
>Jared


I disagree with that statement, I think it rides just fine and those conditions don't apply, IMO. I have 32/11.5s on 7.5" rims. Are you sure those rims arn't 7.5? I thought they were, and the XL gray wheels were 7". They are stamped on the inside of the wheel. My Eddie bauer rims are 7.5". Anyway, the 11.5 width tire has a recommended width of 8-10". Therefore, a 10.5" tire would have a recommended width of 7-9". You're perfectly fine and do not worry about it, 7" is fine. You will not have any problems with ride. I don't have any problems and mine is .5" below the recommended width. I switch from the 32s to 235s every winter so I know what the difference is between the two.


Primary rig is Green Thunder:
95' F-150 XLT 4x4, 302, 5 spd, MSD 6A, Flowmaster Exhaust, Sunroof, Clear corners w/ Diamond headlights, CD player with 2 10" subs and some 32" BFG Muds .

Check out my Gallery for a look-see.


Justin - One Happy FTE Member