When driving your 4 wheel drive offroad it is usual to lower tyre pressures for 2 reasons
- For comfort and a smooth ride.
- To lengthen or enlarge your tyres footprint which will give you greater traction.
By simply lowering your tyres highway pressure from 38 psi to 14 psi (262 to 96kpa) you increase your tyres footprint by 37%
*Click to read Footprint vs Tyre Pressure
This increase in traction enables you to drive to more inaccessible locations. With low pressure, more grip allows you to drive those red clay steep tracks, mould a tyre around a rock or give you greater floatation over mud or sand.
However tyre pressures below 18 psi (124 kpa) run the risk of the tyre either rotating on the wheel rim or worse it allows the tyre to completely deflate and come off the rim. This allows the problem of dirt and mud to enter the inner air chamber or come into contact with the tube (if fitted) thereby damaging the tube or causing resealing tyre bead problems.
A tyre on zero air pressure due to a puncture or a damaged rim which is fitted with Secondair Beadlocks will prevent tyre damage from the wheel rim because the Secondair Beadlock sits 45-50mm proud of the wheel rim and prevents the tyre coming in to contact with the rim.
This situation is easily overcome by fitting SecondAir, a new kind of pneumatic beadlock that fits inside the tyre. SecondAir hold both tyre beads onto the wheel rim and has a separate low profile tube to inflate the beadlock. An easily installed special valve is fitted to the normal air valve hole to inflate the tyre.
Now you have 2 separate air pressures, allowing you to control with confidence the pressure you wish to run in the tyre.
Customers report that even with zero pressure in the tyre due to a puncture, the tyre stayed in position and full control of the vehicle was maintained.
Secondair are an added safety feature to any vehicle.
In the event of a high speed blowout or puncture the SecondAir is unaffected and will continue to hold the tyre to the rim. It also gives the tyre some ‘pneumatic effect’ when the tyre sits on the beadlock, cushioning the tyre from the rim minimising tyre damage.
SecondAir weigh less then 1.5kg each and being distributed completely over & around the wheelrim inside the tyre present no problem with wheel balance. Being inside the tyre the SecondAir is unaffected by weather or damage by rocky terrain. This feature allows long life for the product.
The beadlock tube pressure can range from 40psi to 70psi (275 to 481 kpa) depending on the degree of terrain difficulty or whether used in competition. SecondAir can easily be fitted to most 1 piece steel rims and tubeless tyres.
The purpose of this email is to provide you some information, with regard to your Beadlocker product and its use during a recent test conducted by Defence personnel on the new fleet of vehicles being acquired for the ADF.
The activity was a long range reliability test of a Surveillance vehicle across the Simpson Desert in Nov 2012. The product, which was the Beadlocker® fitted to a 4X4 vehicle used as the support car.
During the transit across the desert, there were no displacements of tyres (no beads compromised), however, it was on the return leg where the product provide to be an actual life saver. I was driving the vehicle fitted with the beadlockers at approximately 60kph on the Cordello Downs Road, 250 kms from Birdsville heading south. The road surface was hard gibber type rocks. I approached a corner which was far more severe than anticipated. It was half way through the corner that the tyre bead on the front offside tyre gave out and I was in serious trouble. In my opinion the only thing that saved me from a serious accident or rollover was that the beadlockers held the tyre in enough to maintain some positive pressure on the side wall.
As a mechanical engineer I understand the forces to restrain the dynamic forces are significant. The Beadlocker is simple, comparatively inexpensive compared to a ruined tyre/rim, and an essential safety item for off road use. You should be justifiably proud of your simple and inexpensive product.
Michael William McMillan MIEAust, CPEng, RPEQ
Mechanical Engineer and 4X4 enthusiast