31x12.50 Thornbirds with No Lift (1 Viewer)

This site may earn a commission from merchant affiliate
links, including eBay, Amazon, Skimlinks, and others.

Joined
Aug 15, 2005
Threads
19
Messages
72
Hello, I need some new tires, the 'all terrains' on my stock 60 are about as good as mini van tires. I would like to get some Interco Thornbirds. They have a 31x11 and 31x12.50 size. Could I put the 31x12.50's on my stock cruiser? Would I have any rubbing on turns?

Also, who has experience with thornbirds? Do you like/dislike them? Should I go for another Super Swamper type? This isn't my DD cruiser, just a fun car, but I will drive it often enough, a few times a week.
 
If you are running stock wheels, the 31x12.50s are definitely too wide, and the 31x11s are probably pushing it.

In any event, Thornbirds are going to be two things, bumpy and loud (think WWII era aircraft).
 
I had 33x12.50 on some 8" wide rims with NO rubbing. You shouldn't attemp to mount something that wide on your factory 6 and 1/2" rims (IF in fact, that is what you are running) You will need at least and 8" wide rim. (correct my if I'm off fellas)

I got some ProComp Mud terrains. Pretty quiet when it comes to spinning fast but as I come to a stop I can fell every knob in the tire. I really like the value. I paid 150 per corner for the 33x12.50 but now wish I had gotten the AllTerrains in a 33x10.50. Buyers remorse I guess. Anyway. Hope that helps.
 
Okay, so I need some new wheels, no worry on that, I don't need anything special, just wider I guess. So if I get 8" wheels and the 31x12.50's, I should be okay? No rubbing? I'm not worried about feeling the knobs, I totally expect this to eventually feel like an offroad car and not a cadillac. Small price to pay if you ask me.
 
Im running ProComp Xterrains on stockers.. no issues and no rubbing. Check out the link in my signature for pics.
 
How do you like the X Terrians? Online store has Pro Comp tire sale of buy 3 get 1 free, the tires a more than the Thornbirds, but I'd still save by getting one free.
 
Only had them a few days. They seem to be fairly quite for a pretty agressive tread. Highway has some humming and when I come to a stop, you can fell the tread but no bad. I am assuming they will get a little less noisey as time goes on.
 
Okay, so here is what I think I'll buy:

31x12.50 Pro Comp X Terrians and 15x10 wheels, 3.75" backspacing on stock not lifted FJ60. Would that work?

(PS - What's my bolt pattern??)
 
Last edited:
Not sure about the backspacing... have yet to buy rims.
 
3.75 backspace will rub the tierod ends if you aren't using spacers. There is also sometimes interference with the brake caliper.
 
If you have to buy new rims anyway, I HIGHLY suggest the Firestone Destination M/T tire. I paid $150 ea for them as well, but get them in the 285/75-16 size (basically a 33x11.5") The tread is super agressive, fairly quiet on the highway, and has never EVER left me stranded.

They also have a 31x10.5 if you're worried about the height.
 
So, i need more backspacing? no problem. can I fit 33's with no lift though? That's a tight fit. 32x11.50 would be nice, but not many come in that size.
 
wheezy said:
So, i need more backspacing? no problem. can I fit 33's with no lift though? That's a tight fit. 32x11.50 would be nice, but not many come in that size.

If you don't have a lift, 33x12.50 will rub, regardless of how wide the wheel is. If you want 33s with no lift, I suggest 33x9.50s.

3.5" backspacing is ideal, but you can get away with a little less, e.g., e.g., 3.25.
 
Following along here and have a question about the 12.50 width. Won't the tire stick out from the wheel wells? If so won't that cause contact even in a 31" tire on stock suspension when the rig flexes hard? And finally, if it does stick out won't the rig get sand/rock blasted because the tire is not under the wheel well?

And I know some don't care about the paint/mud issue..I just want to know for when I start looking for tires again...I don't want to mount up somthing that goes out of the wheel well..
dtrain has a great looking lift and rig but I can't tell from the photos if the tires stick out?
HD
 
High Desert said:
Following along here and have a question about the 12.50 width. Won't the tire stick out from the wheel wells? If so won't that cause contact even in a 31" tire on stock suspension when the rig flexes hard? And finally, if it does stick out won't the rig get sand/rock blasted because the tire is not under the wheel well?

And I know some don't care about the paint/mud issue..I just want to know for when I start looking for tires again...I don't want to mount up somthing that goes out of the wheel well..
dtrain has a great looking lift and rig but I can't tell from the photos if the tires stick out?
HD

I think a 12.5 tire is generally too wide for these trucks, if you care about rubbing or if you care about the sheet metal getting blasted by rocks and other debris. Those of us who care about such things generally run a 10.5" or a 9.5" wide tire.
 
HighDesert - If you checkout the link my signature, you can see some pics I tried to take that show the tire and how far it sticks out of wheelwell. Its is just slighly inside the wheelwell. I was going to go with skinnies bu thought I would go with a chanage and get the 12.5s.
 
How far your tire sticks outside your wheel well is probobly more dependant on the wheel offset than the tire width. I have 11.5" wide tires on Tacoma rims using a .75" wheel spacer up front, and the edge of the tire is even with the wheel well. In the rear, the same wheel and tire combo using a 1" spacer has a LOT more room between the fender and edge of the tire. Apparently the rar axle is a lot narrower than the front.
 
So 33's with no lift won't hit the top of the wheel well under full flex? If 12.50 is too wide then I'll look for a skinnier tire. I plan to lift it sometime, within the next 6 months, so if I could for the meantime get away with 33x12.50's then that would be great, and save me having to buy another new set of tires. I was planning on just running the 31's for a bit and then selling them, obviously taking a loss but I really need to get rid of the POS's I'm sitting on right now.

I did find some 33x10.50 Thornbirds for $135 each.
 
Last edited:

Users who are viewing this thread

Back
Top Bottom