The STI Roctane tires in 30-inch trim dwarf the stock 26-inch ITP BajaCross tires. We tested them on STI’s new 14-inch beadlock wheel.
This year we have seen the release of multiple 30-plus-inch UTV tires from several manufacturers. STI, ITP, GBC and Maxxis have all released tires that are 30 inches tall or larger, and we set out to test the first set of STI Roctane tires available to anyone.
The tread pattern is pretty original, with an alternating center tread block that is fairly open. While this doesn’t do a ton for turn-in, it offers massive grip on loose terrain and rocks.
By the time you read this, the STI Roctane XD tire will be available in 11 sizes, from 25–32 inches tall. They are available for 12- or 14-inch rims, and we tested them in the 30x10R-14 size mounted on STI’s new HD alloy beadlock wheels. Our test unit of choice was a 2012 Polaris RZR XP EPS LE. With 30-inch tires, you’re definitely going to want power steering.
The beadlock wheels are inexpensive. A 12-inch beadlock from STI can be yours for around $110, which is a steal! The 14-inch wheels and 30-inch tires fit well on the rear of our RZR XP, but rubbed in the front. The stock fender flares can be removed, and new holes can be drilled to pull the lower mud-flap portion of the flare back further to clear the tire, or you can remove them completely. We chose to move ours back, as the plastic push pins are easy to align and install. Once installed, the RZR gained some 2.5 inches of ground clearance, seeing as how it was outfitted with 26-inch Bajacross tires stock.
With all the extra ground clearance we gained from the 30-inch tires, we weren’t afraid to climb up rock ledges.
We tested the Roctane tires in some rocky terrain—the Rowher Flats SVRA in Agua Dulce, California, which is Cody’s stomping grounds. The terrain there ranges from sandy riverbed to rock-wall climbs and everything in between, with huge rocks embedded in the ground that tear up tire carcases like you wouldn’t believe. We started with the Roctanes at 10 psi and gradually moved down in air pressure until we found our best setting. At 6.5 psi, the Roctane tires were pliable enough to give over small trail junk and rocks, and able to balloon out and spread the footprint when we needed traction. However, they weren’t overly soft, as the eight-ply construction keeps the tire sidewalls stiff and upright.
With a tire this tall, steering feel is going to be a little more numb, and you lose some high-speed stability. The Roctane tires tracked well and didn’t wobble or vibrate badly, but they did exhibit some side-to-side shimmying when you hit a rut with the wheels turned at high speeds. Before we even drove it, STI’s Craig Petersen explained that the final mold on the Roctane tire will move some of the carcass thickness from the tread base to the sidewall and shoulder, which will remedy this problem that we found after driving it. The tire holds up well to abuse, as we didn’t experience any chunking of the sidewall or damage that would cause the tire to lose pressure.
The tire also features a deep rim guard built to keep the rims from getting scratched in heavily littered rock sections, as well as wrap-around shoulder lugs for good side bite on rocky ledges and cliff faces. In the big rocks, this tire is incredible. Its soft, provides huge traction, and when you air it down, the footprint is absolutely enormous. If you like playing in rocks or deep, rutted terrain, this is your tire. In Moab, the Roctane will be king.
The tires balloon out quite well under heavy load, offering increased contact surface area and bump absorption.
With such a large tire, high-speed stability is lessened, but low-speed comfort and crawling abilities increase. The RZR XP still had more than enough power to fry the big 30-inch meats, which aren’t as heavy as you would think for such a huge item. We loved the Roctanes in the slow stuff, but preferred the stock tires for high-speed terrain coverage. STI is releasing 25-, 26-, 27- and 28-inch Roctane tires as well. We can’t wait to test the 27- and 28-inch models, as they better suit our needs for high-speed terrain coverage! Prices are still to be determined. Contact STI Tire and Wheel at (318) 255-0049 or www.stitire