I don’t actually know how to play chess, so bear with me for a minute here. Four-wheel driving is like chess. Well, maybe Risk, or snooker, or perhaps Cluedo. The point is, while the spinning tyres and flinging mud get all the Instagram likes, it’s much more of a strategic affair.
Man vs machine, machine vs terrain; knowledge and skill vs practicality and good sense. It’s an ongoing struggle identifying the weak points of the vehicle’s abilities and strengths, addressing them to make things go farther and harder, and trying to keep the whole affair on the road long enough to actually go for the occasional four-wheeling trip with your mates. And ultimately, it all comes down to one thing: traction.
Y’see, where bigger turbos send more power down the line, bar work armours your rig, and lockers ensure drive goes to all four wheels, continued progress in tricky terrain ultimately comes down to just a few square inches of rubber on the track propelling you forward and, just like chess, tyre pressures can make all the difference.
Dropping tyre pressures gives a whole host of benefits off-road (although more on that later), but it also comes with a whole host of negatives too (more on that later as well, actually). But the wheels you choose to wrap your tyres around can play just as big a part in off-road performance as the tyres themselves.
Over the next few pages we’ll be airing down and shining the spotlight on beadlock wheels – the pros and cons, the situations they can get you out of and, most importantly, what it means to get caught running them – the good, the bad, the ugly.
So torque your wheel nuts and lock your hubs, ladies and gentlemen … it’s beadlock time.
Beadlock wheels - The Good
Before we get stuck into the nitty-gritty of why beadlocks help off-road, it’s important to run through the fundamentals of why we want lower tyre pressures. After all, while you’re no doubt a grizzled outback adventurer with red-dirt running through your veins, we’ve all gotta start somewhere, and many seasoned veterans don’t understand what making your tyres ‘bag-out’ actually means, and why it’s the secret sauce for a good day on the tracks.
Pending any Flinstones-esque breakthrough in technology, tyres are typically round, allowing them to roll. There is a little asterisk on the end of round though. If they were perfectly round the contact patch would be non-existent, leaving you to sit there spinning your tyres due to a lack of grip. So it’s the small flat contact patch on the bottom that actually allows the tyre to grip the surface resulting in the potential for forward drive. The more surface area, the more grip.
It’s this surface area we’re taking advantage of when airing down. Starting with a 35-inch tyre at 36psi gives us roughly 300mm of contact patch on the ground for a surface area of 952cm2. Dropping tyre pressures down to 18psi lengthens that footprint to around 350mm for a surface area of roughly 1111cm2.
Dropping even further again, down to an insanely low 8psi, gets that contact patch out to roughly 400mm for a surface area of 1270cm2, which is 32 per cent more surface area, and 32 per cent more grip sending you up the track. There’s a common misconception that the tyre gets physically wider, too, and although the sidewall might bulge out the contact patch is relatively limited by the tread face.
The lower the tyre pressure, however, the more likely the tyre is to physically come off the wheel (see the breakout ‘Take A Seat’ below). This is where beadlocks come into their element. Where a regular wheel requires internal air-pressure to maintain the connection between the tyre and wheel, a beadlock wheel physically clamps the tyre to the wheel with a locking ring and bolt system. Even at 0psi there’s essentially no chance the tyre is coming off.
Beadlocks allow you to safely run lower pressures than you could with a conventional wheel. Bogged to the hilt in soft sand and just keep digging? Drop to 0psi if you need to and drive out with near tank-track like contact patches giving you grip. You can also drive with more confidence at low pressures in both high- and low-speed driving.
Where a sharp steering input on a non-beadlocked wheel can peel the tyre bead away from the wheel, a beadlock ensures it’ll stay put. This benefit extends to hard low-speed driving, too. Think of the shock load a tyre is subjected to when sliding off a rock ledge and gripping again, and you’re on the right path to understanding the benefits of a beadlock wheel.
The low pressures you can run also allow the tyre to deform over rough terrain like rocks, giving you grip and also decreasing the chance of damage to the tyre. Sounds like a good thing only better, right? Not exactly, but you’ll need to keep reading to find out why.
Beadlock wheels - The Bad
There’s no such thing as a free lunch, and beadlock wheels are no different. While they might sound like a miracle cure-all that will fix your tyre-pressure issues, the reality is there are plenty of downsides.
Where a typical tyre seats in a relatively simple fashion, a beadlock wheel requires a complicated bolt and ring system where upwards of 30 individual high-strength bolts need to be precisely torqued to ensure the ring provides equal pressure on the tyre bead, keeping it clamped in place.
As torque is applied to these bolts the tyre bead is compressed, meaning you’ll need to run through each individual bolt multiple times in a star pattern to ensure even and accurate pressure is applied. With 30 bolts, and three passes each, that’s 90 bolts that need to be tightened per wheel – 360 just to do a standard 4x4 without factoring in spare tyres. Don’t be surprised to find most tyre shops refuse to fit them due to inability, inexperience or simply a case of covering their arses, so you may need to contact a specialist shop.
The bolts will require routine re-tensioning, too. With road vibrations, the bolts can back out ever so slightly, putting more load on the bolts on either side. Left unchecked, these bolts can snap under load, creating a chain reaction that can leave you with five to six bolts in a row snapped off, allowing the locking ring to flex and the tyre to come unseated from the wheel. If this happens at speed it’ll be the equivalent of a tyre blow-out.
While the addition of a solid chunk of alloy on the outer edge of the wheel increases strength and reduces the chance of wheel damage, it also increases unsprung weight; there’s additional material on the wheel, the ring, the bolts, washers and nuts used to hold the whole affair in place.
That additional unsprung and rolling weight will negatively affect acceleration, put more load on the brakes and reduce ride quality, as your suspension will have to work harder. And the locking ring will collect rainwater and mud, just waiting to blast you in the face every time you come at it with a pressure washer.
Most of these issues are avoided by regular maintenance and an understanding of the affects modifications can have on your vehicle, but that won’t mitigate the legal ramifications of running these wheels.
Beadlock wheels - The Ugly
Fitting beadlocks for off-road use is all well and good, but when you’re doing hot laps of Chapel Street in your sandy taupe 79 and the local constabulary turn on their blue and red party lights, what are you actually getting pinged for? And this is the part that hurts. Y’see, beadlock wheels aren’t actually illegal, they’re just not legal. Let us explain.
In Australia, laws typically function on being approved rather than being disapproved. Beadlock wheels simply haven’t been approved, and nor do they fit into the standards that have already been approved so, by default, they’re not legally able to be run, and therefore running them is illegal.
Clear as mud, right? Think of it a little like running around with a rocket launcher just because the law didn’t specifically say you couldn’t.
In the case of being pinged for beadlocks, you’ll likely find yourself slapped with an infringement notice stating “Use Light Vehicle not comply with standard”, as well as a few demerit points for your trouble, and a $112 fine.
We’ve spoken to multiple police and highway patrol officers up and down the country looking for a specific answer as to what law has been broken when running beadlocks, but non-compliance is the closest explanation we’ve heard … off the record, of course. So why don’t they comply?
There are a few theories but most of them can be debunked by looking at other approved wheels. One theory is the tyre is mechanically connected to the wheel, placing extra stress on the tyre’s sidewall, although Hummer H1s are legally sold here with an internal beadlock that does exactly that.
The only actual difference is the way the tyre physically seals; in an internal beadlock, like a Hummer H1, the tyre still seals on its outside edge, with an internal piece re-enforcing a typical bead, but an external beadlock seals on the inside edge of the bead (where it wasn’t designed to seal) with an external piece re-enforcing the outer edge. Put simply, the wheel works differently to how the tyre manufacturers and the government think that a wheel should work.
Another issue is the multi-piece construction of a beadlock creating potential failure points, although again multi-piece streetcar wheels and split rims are still legal on the road, and these can have the same issues.
So couldn’t a wheel manufacturer strive to make beadlocks legal? The short answer is yes, but the longer answer is why would they? Australia has a long history of laws being challenged and repealed, standards being modified, and legal strategies completely changing. Hell, it’s the whole reason we have a High Court. But it costs money … and bags of it.
A manufacturer could challenge the ADRs, but would they sell enough beadlock wheels to cover the costs to have the standards redefined? And would it actually make a difference to the people already choosing to run the gauntlet for better off-road performance? Probably not.
Take a seat
As many times as our kids have made us sit through the Harry Potter anthology, the unfortunate reality is tyres don’t magically hold themselves to the wheels they’re fitted to. In most modern wheel and tyre combinations there’s a thick outer edge on the tyre known as the bead that seats into a corresponding cup on the wheel.
Huge air-pressure is required to get the bead over the lip and into the cup, where it’s held in place by typical road pressures and surface friction between the tyre and wheel. It’s an elegantly simple solution that works perfectly 99.9 per cent of the time. The only downside is the less internal air pressure, the less force there is keeping the bead seated, which can cause issues when lowering pressures off-road.
Mechanical beadlocks aren’t the only solution to stop your wheels spinning uselessly inside your tyre, especially when you’re on a budget. Prepare to have your local tyre shop hate you (and this is possibly more illegal than just running beadlock wheels) but a smear of Sikaflex between the wheel and tyre can strengthen the bond between the two, keeping it in place when running slightly lower air pressures in tougher terrain.
The Sikaflex will only come off with a wire wheel though, so maybe don’t do this trick. Some bush-bashers on private property take this idea a step further and run small screws through the wheel’s outer edge and into the tyre, which stops it spinning on the wheel, and using an even bigger helping of Sikaflex to seal it up again.
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