Bead locks are all the rage-if you don't have a set already then you've probably at least thought about getting some. Problem is, they're not all the same. Sure, they all have a common goal: to mechanically clamp the tire's outer bead to keep the tire in place no matter what. But there are a few differences between the bead-lock wheels currently used for off-roading. One bead lock might work better than another for your vehicle and the type of four-wheeling you do.
For this issue, we tested a set of Allied Rock-A-Thon bead locks available through High-Impact Marketing. Just like all the common bead locks for four-wheeling, the Rock-A-Thon wheels have a conventional safety bead for the inside bead, and a lock ring that clamps the outer bead against the wheel. The first difference with the Allied wheels is that they are one of the few that you can actually get in a 17-inch diameter. A few years ago, only BMWs and gold-plated low-riders cared about tires that fit wheels larger than 16 inches. But BFGoodrich and Goodyear both make some swingin' mud tires that fit 17-inchers now, including the much-drooled-over and very difficult to obtain BFGoodrich Krawler T/As. So the wheel industry evolves and Allied was one of the first to actually deliver a 17-inch bead lock.
The other primary difference with Rock-A-Thon bead locks is the design of the lock ring. It is much thinner than most rings, and it's made of steel, not aluminum. Most people we talked to thought that the rings wouldn't be strong enough to distribute the clamping load evenly, and that they would get damaged too easily. Turns out that they couldn't be more wrong. The steel lock rings are shaped to match the common angle of a tire's bead. This shape gives the steel rings greater strength and the outer lip protects the bolt heads from rocks. The contour of the rings also centers the tires on the wheels making assembly easy, and aiding in keeping the tires centered on the wheels as you're bombing down the road. Finally, the rolled outer edge of the ring won't cut the tire if you run at extremely low air pressure and shove the wheel into the tire.
We assembled a set of the Rock-A-Thon wheels and then set out on Ultimate Adventure 2002. For a few thousand miles, we aired way down, thrashed them on the trails, aired up, and hit the road. Unlike other bead locks, the Rock-A-Thons didn't lose any air pressure overnight. In fact, the vehicle sat for two months when we returned home and held the air pressure the entire time.
High-Impact Marketing sells the Rock-A-Thon wheels in a variety of bolt patterns (even Super Dutys) and backspacing options, and can even work with you on custom backspacing (within reason). You can have yours in 15x7, 15x8, 15x10, 15x12, 15x14, and 17x8 sizes.
A bead lock holds the tire firmly on the wheel by clamping the tire's bead between a lock ring and the wheel. The Allied Rock-A-Thon bead locks do not have a centering ring on the wheel, but use the contoured lock ring to position the tire instead. This concerned us at first, but the tire is easy to center, the wheels are easy to assemble, and we've had no problems with the tires shifting on the wheels after plenty of on- and off-road use.
The lock ring on the Allied wheel is fairly unique. The flat portion that squeezes the bead is only 11/48 inch thick. The outer lip of the ring is bulky and shaped to hold the tire in place, and it also does a good job of protecting the bolts from rocks. We've drug these wheels over several rocky trails, against a few curbs, and we can still put a socket on all of the bolt heads. The contour of the rings make them strong and greatly improves the tire seal on the wheel.
This tire has been run for about 3,000 miles. The darker ring (arrows) shows the full clamping area of the ring. We believe that this design holds the bead on the wheel better. This and the solid welding on the wheel contribute to its ability to hold air pressure so well.
The number of bolts on a bead lock determines how uniform the clamping force will be on the wheel. These allied 17-inch bead locks have 32 51/416-inch Grade 8 bolts. The larger the diameter of the wheel, the more bolts the wheel should have. We inspect the gap between the lock ring and the wheel periodically as a quick visual way of checking that the bolts are tight. If the gap is inconsistent around the wheel, you have some bolts loosening. Yes, this is common even on high-quality bead-lock wheels.
You're supposed to torque the lock-ring bolts to about 15 lb-ft in a criss-cross pattern. A final feature of the Rock-A-Thon lock rings is that the rolled edge won't cut a tire when you're showing off with 0 to 1 psi of air in the tire. The Allied Rock-A-Thon wheels are available in steel (two styles). Aluminum wheels may soon be available too.