You might have seen that the new F-150 Raptor is available with beadlock-capable wheels. This isn’t anything new - Ford has offered beadlock wheels from the factory before, and they’re also an optional extra on the Jeep Wrangler.
As for the purpose of beadlock rims, the clue’s in the name - they’re all about holding the bead of the tyre more securely. Normally, air pressure is sufficient to keep the bead pressed firmly against the inside edges of the wheel rims, ensuring both rotate in unison.
However, during especially extreme off-roading, drivers will often reduce pressures to increase the tyre contact patch. The only problem is, on conventional wheels, you run the risk of unseating a tyre. And that’s where beadlock comes in.
The concept, which has roots in military vehicle applications, is simple enough to get your head around. On one side of the wheel, the tyre bead sits over the lip of a rim, with a lock ring bolted on top. The latter is secured with a series of bolts, leaving the tyre bead neatly sandwiched between two bits of metal.
Typically, this is on the outer side of the tyre, as it’s usually under more strain. If installed correctly, you can run pressures down nice and low without fear of the tyre getting ripped off the rim.
Yes, we did say “if installed correctly,” as that’s one of the main downsides of beadlock wheels. There could be as many as 30 or even more bolts to tighten on each wheel, each of which needs to be torqued correctly. This needs to be done in a pattern, too, to ensure the lock ring clamps down evenly and doesn’t pinch the bead anywhere around its circumference. Once that’s done, the torque of each and every one will need to be checked periodically.
There’s also the question of road legality, which varies from nation to nation. In many markets, beadlocks don’t have regulatory approval, but at the same time, they’re not explicitly prohibited either, creating a grey area.
One way around any legal doubts is with hybrid beadlock wheels, which can be run conventionally or with a lock-ring in place when you’re away from the road. It’s these kinds of beadlock rims you’ll typically see a major manufacturer provide from the factory or as accessories, normally with a bunch of warnings on the instructions about only using them off-piste.
Solution number B involves an entirely different approach to the same problem. Inflatable beadlock devices involve an inner tube that wraps around the centre of the wheel, requiring a hole to be cut in the dish for a valve to poke through. Once pumped up to the required pressure, the tube pushes the beads on either side of the tyre into the rims. Some of these devices have DOT approval in the USA.
It’s also worth noting that beadlock devices aren’t the preserve of the off-road community. They’re also used in the drag racing world, where tyre pressures are often lowered dramatically to give a better contact patch with the Asphalt. These are of the traditional bolted variety, and in some NHRA categories like Top Fuel, the forces involved are so violent that lockrings are found on both sides of the tyre.