I'm building a new project right now, a 1990 Jeep YJ Wrangler. I'll be writing all about it here at Extreme4x4.com, but, right now, I had to think about what tires I wanted to run.
Like you, I enjoy extreme rock crawling. I also enjoy four-wheeling such as backcountry exploring on easier trails, such as you run into all over the west. While you can travel the easier roads with just about anything, the extreme trails require pretty specialized equipment, including tires.
Those of us who are "old timers" in the sport had to run bias ply tires before about 1978-'79, as that was all there was. When BF Goodrich, the pioneer in off-highway radials, came out with their new Radial All-Terrain TA, the game changed. Many four-wheelers (but not all) switched over to radial tires for their ability to wrap around the terrain and for their great street performance, in spite of weaker sidewall construction. I held on to my Armstrong TruTracs and Goodyear Wrangler RT's until about 1986, when I took the radial plunge and didn't come back. Until now.
In 2001, the sport of extreme rock crawling and the extreme trails that are cropping up all over have shown us a weakness of radials. While a slit sidewall in the backcountry was a nuisance, a slit sidewall in a competition can mean the difference between winning and losing an event. Goodyear, with their Wrangler MTR's, Interco, with their Super Swamper SSR's and BF Goodrich, with their Radial TA's, have addressed the sidewall problem, building radials that can really take abuse. This is proven by the fact that many competitors use those tires. The trouble is, with the tougher sidewalls, the radials have lost some of the flexibility advantage they had over a bias tire. Goodyear made up for this with a fairly sticky compound that seemed to work well. We've noticed lately that the new Goodyears don't seem to be gripping any better than anyone else's tires, though.
When the MTR's first appeared on the scene, we checked the durometer of a 35x12.50R15LT, which was an excellent 53 (we've found the lower the number, the better for us rock crawlers, as the tires grip better). Super Swampers hovered around the 55-56 range (still good) and the rest of the pack came in at anywhere from 58 to an extra-slippery 66. After watching a set of 37" Goodyear MTR's slither around on rocks and not hook up any better than anybody else's tires, we checked their durometer again. It was a 58! Goodyear claims no changes have been made to the tires, but the durometer meter doesn't lie. Lower durometer tires don't wear as well as higher durometer tires do and maybe Goodyear changed the compound because of wear complaints. Only they know the reason for the change, but I know that after I crowed about how great the MTR's are, I owed it to you, our readers, to let you know that, while they're still an excellent tire, the MTR's aren't any better (or worse) than anyone else's tires.
Radial tires have one other annoying problem that I forgot to mention. That's the infamous "radial bounce." When aired down, a radial will tend to wrap | up and unload; causing a bounce that can get uncontrollable when trying to climb a steep slickrock waterfall. You'll also get the bounce when you drop sideways off a rock or ledge and the vehicle rocks sideways for a while.
Bias ply tires do none of these things. In fact, when I took my first ride on bias tires in 14 years, it was hard to wipe the smile from my face. You see, I'd forgotten how "dead" bias tires were. There was no bounce, no rocking, just great control on the trail. You also don't have to drive as if every rock has a knife imbedded in them, as the bias plies have tough, four-ply sidewalls.
Now, there are a couple of different design bias tires available to us. One is a "bias-belted" design, that has polyester, nylon or steel belts running circumferentially around the tread area to control squirm, and regular bias tires, where the bias belts criss-cross each other from bead to bead, just like a bias-belted tire, but have no extra belts around the tread area.
Mickey Thompson and Interco both offer excellent bias belted tires, the Super Swamper TSL SX being the tire we seem to see the most in the backcountry here in the west, with its steel-belted design. I thought the SX was a pretty nifty tire, too, its only problem being weight. I got to thinking that maybe the regular TSL would work even better for me, as it deleted the steel belts around the tread, allowing the tread to wrap around rocks better and maybe even being lighter than the SX. A call to Interco confirmed this. A 38x12.50-15 SX weighs in at 85 pounds, whereas the same size TSL weighs 71. That's a whopping 14 pounds per tire! The 36x12.50-15 TSL weighs only 64 pounds, which is competitive with wimpy radial tires. And, that's with its beefy four-ply nylon sidewalls! The one downside is that the nylon tire thumps a bit when cold, something that's never bothered me when factoring in the incredible toughness of nylon over any other cord material.
Mickey Thompson is working on a new, non-belted Claw with a durometer in the 40's and Interco is souping up an SX with no steel belts and a stickier compound. Rock crawlers will greet these tires with joy. For now, considering everything we've just talked about, I believe I'll choose Super Swamper TSL's until the new high-zoot tires appear. Radials don't do the job I need anymore, which I especially noticed once I tried the Super Swamper TSL's.
Now, you guys with your sport utes who explore graded dirt roads, don't write and say how wrong I am about your radial tires. There's nothing wrong with the use you put your vehicle to, or the tires you choose to run. This editorial has been about the tires I feel are best suited for what I do with my 4x4 (if I didn't do extreme four-wheeling and drove the Jeep extensively on the street, I'd choose radials). My friends who never switched to radials are having a good laugh at my expense, by the way.
Long live smaller tire companies like Interco (Super Swamper) and Mickey Thompson who supply us with tires the big corporations don't want to touch! |
