One of the best-known secrets to off-roading is that lowering your tire's air pressure can help increase traction. In fact, one test we did in the mud a few years back showed that by going from 25 to 12 psi in our tires we could get twice as far across a muddy bog.
The problems arise when you lower your rubber so much that the tire is barely held onto the rim, because, let's face it, the wheel was designed to hold a tire full of air at street pressures. Most wheels have a small lip or safety bead that helps keep the bead of the tire on the rim while at lower than street pressure. However, depending on vehicle weight, once you start dropping below 12 psi, you are risking whether or not the tires will stay on the rim, especially if you are in a heavy vehicle or encountering rough or narrow terrain that puts a lot of stress on the sidewall of the tires and pushes them off the rim. We recently tested two new styles of bead locks, and were extremely impressed with both.
Our original plan was to install the Staun internal bead locks on our Ultimate Tacoma before our weeklong Ultimate Adventure off-road trip, but between time constraints and the fact that we were running aluminum alloy wheels, we ended up going on Ultimate Adventure without any bead locks, and paid for it. In one particular trail we lost a bead on both rear tires when running 8 psi of pressure. Upon returning we decided to test both the Staun internal bead locks, but on a set of steel wheels, and have a set of OMF bead locks installed on our American Racing wheels that we ran on the Taco. The OMF bead locks are some of the cleanest manufactured and nicest-looking bead locks on the market, and they work awesome on top of that. The Staun internal bead locks work by having an innertube inside a strong polyester casing. This tube stays at 40 psi, while the tire can be dropped to low-single-digit pressures, and the inner tube will lock the tire to the bead of the rim. In the end we found that either set of bead locks would be great for a trail rig, and though we can't condone or disapprove of the use of bead locks on the street, we can say that in our testing the OMF bead locks worked great at highway speeds and look very similar to OMF's SIM-U-LOCK, while the Staun bead locks where happy at 65-plus mph and can't be noticed unless you see the second valve stem on the wheel.