Largest tire for Rubi wheels?
JK Super Freak
Joined: Jan 2008
Posts: 1,835
Likes: 0
From: The Deep Dark Woods of Texas!
35x12.50x17s are about it, you could go to 37x12.50x17 but the taller narrower tire on the narrow rims give you just a bit of sidewall play on the road. 12.50 is something we "get away" with but also not recommended by most tire shops like Discount, 4wheelparts, etc. You have to play with your optimal tire pressure with the aforementioned size to keep from wearing down the middle due to the narrower rim and "suggested" tire pressure. I run about 25 - 30 lbs and they are wearing normal.
JK Super Freak
Joined: Sep 2007
Posts: 1,623
Likes: 5
From: Lawrenceville, NJ
I assume you mean what's the WIDEST tire that will clear w/o a wheel spacer?
That would be about a 285 mm for most people (Jeeps ALWAYS have variation...two on the lot that should be identical might have different parts, different specs, different clearances, different mounting hole locations, etc....its part of their unique charm....)
Remember...there's more than one factor to consider when getting new rubber...its NOT just what fits on the rim.
If the tire has a larger diameter...its ends are swinging in a wider arc when you turn, or droop one tire down, and stuff the other tire up into the wheel well....the upper inside edge of the tire can hit the frame rail for example, but all of the larger arc issues exist....AND, even on a straight up tire stuff, the top of the tire is heading right at the top of the wheel well, etc...which means that the the taller tires can reach more stuff to hit/rub on than a smaller diameter tire.
A wider section width tire sticks out on both sides of the rim, and, depending upon the backspacing...makes the rubber closer to the inboard stuff, and/or, too close to the fender lip on the way up, so it hits, etc.
The section width of the tire is NOT the tread width...section width is JUST the sidewall bulge itself, across.
An aggressive tire with knobby lugs, etc...can grab onto your jeep on the way around, and paddle your wheel wells, etc...where a less aggressive tire might have fit with no rubbing/paddling, etc....so the SPECIFIC tire makes a difference as well.
For example, tire sizes are NOMINAL, meaning, ball park, NOT exact. The metric sizes tend to be mmore accurate, but, generally, a 35" tire might be anywhere from 33.5"- 35.5", and so forth...so an anecdotal post by some random JK'r that he has XYZ sized tires and had no rub, or they rubbed like crazy...etc...means very little to YOU...unless you are buying his JK.....etc.
I've seen people run 13.5's on 7.5" rims...and, they were fine, but that's a practical limit IMHO.
The actual test we use to determine if a tire/rim combo will wear well, etc...is a chalk test....used to determine the ideal psi, etc.
If the tire is not applying pressure evenly across the tread face, then the psi and or rim is not working properly...some tires are very lenient in this regard (BFG AT ko's are a great example...very tolerant of rim width), some tires are more finicky.
That would be about a 285 mm for most people (Jeeps ALWAYS have variation...two on the lot that should be identical might have different parts, different specs, different clearances, different mounting hole locations, etc....its part of their unique charm....)
Remember...there's more than one factor to consider when getting new rubber...its NOT just what fits on the rim.
If the tire has a larger diameter...its ends are swinging in a wider arc when you turn, or droop one tire down, and stuff the other tire up into the wheel well....the upper inside edge of the tire can hit the frame rail for example, but all of the larger arc issues exist....AND, even on a straight up tire stuff, the top of the tire is heading right at the top of the wheel well, etc...which means that the the taller tires can reach more stuff to hit/rub on than a smaller diameter tire.
A wider section width tire sticks out on both sides of the rim, and, depending upon the backspacing...makes the rubber closer to the inboard stuff, and/or, too close to the fender lip on the way up, so it hits, etc.
The section width of the tire is NOT the tread width...section width is JUST the sidewall bulge itself, across.
An aggressive tire with knobby lugs, etc...can grab onto your jeep on the way around, and paddle your wheel wells, etc...where a less aggressive tire might have fit with no rubbing/paddling, etc....so the SPECIFIC tire makes a difference as well.
For example, tire sizes are NOMINAL, meaning, ball park, NOT exact. The metric sizes tend to be mmore accurate, but, generally, a 35" tire might be anywhere from 33.5"- 35.5", and so forth...so an anecdotal post by some random JK'r that he has XYZ sized tires and had no rub, or they rubbed like crazy...etc...means very little to YOU...unless you are buying his JK.....etc.
I've seen people run 13.5's on 7.5" rims...and, they were fine, but that's a practical limit IMHO.
The actual test we use to determine if a tire/rim combo will wear well, etc...is a chalk test....used to determine the ideal psi, etc.
If the tire is not applying pressure evenly across the tread face, then the psi and or rim is not working properly...some tires are very lenient in this regard (BFG AT ko's are a great example...very tolerant of rim width), some tires are more finicky.
Last edited by TEEJ; May 9, 2008 at 04:27 PM.
JK Enthusiast
Joined: May 2007
Posts: 489
Likes: 1
I'm running 37x12.5x17 BFG MT's on the stock Rubi wheels. I am running Spidertrax spacers for clearance. I love the stock wheels and couldn't find anything I liked better aftermarket. The narrowness of the wheels also allows allows more of a cushion when airing down as the tire is less likely to pull off the bead. In more extreme terrain I generally run 10psi front and 8psi rear and have not slipped a bead or spun a tire on the rim.
JK Newbie
Joined: May 2008
Posts: 89
Likes: 0
From: Amherst, Mass
I've got the 1-1/2" spacers on my stock rims and tires. I'm about to put 35-12.50s on the stock rims. How much are they going to stick out past the fenders ? Seems like the stocks are just about even now.
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JK Junkie
Joined: May 2007
Posts: 3,931
Likes: 3
From: slp. Mexico
I'm running 37x12.5x17 BFG MT's on the stock Rubi wheels. I am running Spidertrax spacers for clearance. I love the stock wheels and couldn't find anything I liked better aftermarket. The narrowness of the wheels also allows allows more of a cushion when airing down as the tire is less likely to pull off the bead. In more extreme terrain I generally run 10psi front and 8psi rear and have not slipped a bead or spun a tire on the rim.
