12.5" on a 7" rim, whats the verdict?

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M23TLC

M23TLC

10 Year 15 Year
Joined
Sep 2, 2007
Threads
25
Messages
220
Location
Central NJ
Hey all,

'92 guy here who likes the old school look and quality of his 15x7's. Problem is, it seems I have limited tire choices because of the 7" rim (especially in the 33" range).

Ive read a bunch of threads on this via a google search and on here and there seems to be no clear answer. To make it more complicated, different tire manufacturers offerings of a "33" tire could be totally different. Case in point, an Interco TSL 33/12.5/15 measures a whopping 33.7" whereas a same size ProComp is only 32.5". More importantly, the WIDTHS of these tires differ.

I like the Interco tires and seems the only option I can get (according to the suggested rim size) is the TSL Radial 32/10.5/15 which is a bit smaller than what I would like. So, the question is, can I put a 12.5 tire on to my 7" wheel to expand the options a bit?

As far as use, I drive 10min to work and back daily and wheel it about once a month in sand/mud conditions. That said, I wouldnt want to be scared about taking a 3hr trip because the tire size doesnt match the suggested size.....
 
I've run 12.5 tires on 7 inch rims already. It really shouldn't be a problem. It is known as a poor man's beadlock, as the tire is less likely to roll off the bead. Some shops won't want to install them however, seeing as they aren't the recmmended size. Find a shop that does, and run them without fear.
 
The reason it is hard to find a shop to mount them is because it is a PITA getting them on. Older tire machines will really struggle to get the bead on especially with a tire as stiff as a Swamper. There are other tires you can get in taller sizes that will work fine on a 7" rim. The Q78 would be a prime example. The 33x10.5 and 34x11.50 Swampers would work nicely on a 7" rim, if you don't want that aggressive 33x10.50 BFG ATs and MTs come in that size.
 
I woldn't go 12.5 on a 7" simply because if you plan on doing any amount of pavement driving you'll have the center worn in a hurry. Even on an 8" which is what I run, yo still get that over-inflated look. I love the ability to run them at 10lbs of pressure without blowing a bead, so I accept it. A 7" is gonna be pretty bad for that. I'd go with a 10.50 or so as was suggested earlier, or plan on having bald center in about half the mileage.
 
I've done it, no ill effects including wear. I wouldn't hesitate do do it again.

As with just about any question requiring opinions, you're gonna have a hung jury.

-Spike
 
It is actually a good fit the taller your tire gets. I ran 34x12.5x15 trxus on 15x7 rims on my old XJ. Great combo.

That's actually the Interco tire I'd recommend you look into (34.0" size) for an 80 where you don't want to go as big as a 35. Killer in between size that will work excellently on a 15x7 rim.
 
-Spike- said:
As with just about any question requiring opinions, you're gonna have a hung jury.

-Spike
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Thats what I was hoping to avoid :D No one has chimed in with a horror story yet. Thats good I suppose.

ginericLC said:
There are other tires you can get in taller sizes that will work fine on a 7" rim. The Q78 would be a prime example. The 33x10.5 and 34x11.50 Swampers would work nicely on a 7" rim
Click to expand...

Funny, I was set on the TSL in the 33/10.5 size.....until I looked at the actual size. 7.9" is the tread width which seems awfully small. I do need some traction on a dry road.

As for the 34", I feel like I would need to regear. And if Im gonna regear, Im gonna do a locker and then tires turns into a $$$$ project.
 
alkaline747trio said:
Regear on 34s? Pfft...I run 38.5s and a 200lb roof rack on stock gears (motor has been massaged SLIGHTLY though). Go with the Trxus as long as they balance out well, that size would be a good one on a no lift or low lift LC.
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I agree - 33" vs. 34" is about meaningless. People have way too big of an expectation that 33's don't also push gearing. Look at all the folks who love the 295 size. That's a half inch to a 34 that is going to be a very serious all around tire.

I can't see not regearing a 3FE even for 33's for the long run, but that's all really tolerance for driver pain. 150 or so HP pushing nearly 3 tons and undergeared is not going to be fun for long. Better get some high protein feed for those squirrels :D
 
Yea, regear in the long run...but for temporary (up to 2 years), you wont hate it that bad..just get over going fast. I think stock gearing on the 3FE should be 4.56, 4.88s for 33-35, 5.29s for 35+, but if you keep out of OD, stock gearing isn't bad on a 38" tire around town and cruising back roads..interstate driving just sucks on a 3FE though.
 
Ok, so I just mounted a set of 35x12.5/16 TrXus on factory toyota 16x7 rims. First of all the tire shop told me that what they have been doing to get these to balance out better is air them up to 80 or 100 psi and let them sit over night in the office. So I had them air them up no weight and drove for 3 day's with them at 80 psi. Then went wheeling and aired them down to 8 and wheeled all day drove home on 8 psi and they were great no vibrations or anything at 80 mph. Second I love my wheel size. The look, the poor man bead lock, all of it. Again just my .02
 
Per Nay's suggestions, I stumbled upon the 34/10.5/15 LTB's which Im leaning toward now. They are very cheap in comparison ($143ea), lighter than a 12.5, and killer on the trail from the reviews Ive read. Ya, I know, you pay for it on the street :D
 
M23TLC said:
Per Nay's suggestions, I stumbled upon the 34/10.5/15 LTB's which Im leaning toward now. They are very cheap in comparison ($143ea), lighter than a 12.5, and killer on the trail from the reviews Ive read. Ya, I know, you pay for it on the street :D
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When I was in the Nissan community, a local ran those LTB's. And while a great tire off-road, he wore them out completely in only 10,000 miles. I would hate to see how those wear on a heavier 80.
 
In the almost 6 months Ive had my 80, Ive put on 1800 or so miles. That works out to about 4K miles/yr. I do know about the tire wear issue. Not saying I like it of course but in my case Im not as affected I suppose. Thanks for the heads up effort though..
 
Bear80 said:
Hu? You have 16x7 wheels? The typical 80 series wheel is 8" wide unless you have a US spec 91-92 with the 15x7" wheels.

The whole air it up etc. is a meathod for bias plys. No radials, no matter how aggressive they are need that.
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Your knowledge of factory 80-series alloy wheels is impressive... However, RSC has 16x7 4Runner steel wheels with 4" backspacing.:rolleyes:

Just remember that MrT made wheels for other vehicles that fit on an 80. :flipoff2:
 
Has anyone tried a 35.15.5.15 Baja Claw on a stock 15x7 offset 8 rims lmk.thing to do it by hand for a spare. Taking a brake.whew. will it work ?
 
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