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4WD TYRES

TYRE CONSTRUCTION & APPLICATIONS

    These details have been put together to assist people's preparations for Tours and Expeditions. The information is drawn from experience in the western deserts of Australia.

TRAVEL DEFINITIONS

• ON-ROAD - Sealed or Bitumen roads and highways
• OFF-ROAD - Gravel roads, dirt tracks, wheel tracks. If you have a path to follow, then you are off-road.
• OFF-TRACK - Cross-country travelling, no tracks or paths at all

TYRE TYPES for 4WD VEHICLES

    Discussions and arguments about tyres having been going since before the only choice of 4wd was either a Series 1 Land Rover or a worn out lend-lease Jeep, we at Beadell Tours have noticed that most tyre debates are generally based on misinformation, advertisements or worse, third-hand anecdotal evidence. Few people have extensive experience of all 3 4wd conditions.
    We have put this together as a laymans description of the tyres that are available now for the three types of 4wd travelling.
    We would like to point out that Off-Track travelling is the least understood of the travelling conditions, particularly in the western deserts.
    There is not a tyre available that can do all 3 jobs satisfactorily.

Keep an open mind; valid opinions can only be formed through experience.

Oops!! This tyre was repaired and made serviceable.

TYRE TYPES AVAILABLE

· STEEL BELTED RADIAL Tyres, the most common tyre available. They are light and supple, capable of good On-road and good Off-road performance. 95% of travellers will only ever need these tyres. Normally between 6 & 12 ply.
· ALL STEEL RADIAL Tyres, these are specific Light Truck tyres with steel belting in the sidewall. They are for extreme working environments where weight carrying and sidewall toughness is required, such as mining and construction sites. MRF, Toyo & Goodyear manufacture 14 ply tyres like these.
· BIAS PLY (cross ply) Tyres, the original and best tyre for Off-track conditions. Tyre construction resists cuts & stakes, (do not confuse Rock-Climbing tyres with Off-Track tyres). Off-Track tyres will be in ply ratings up to and including 16 ply. Serious Bias Ply tyres are now only made by a few manufacturers. The most popular Off-track tyres would be MRF.

    In a nutshell, Steel Belted Radials are the best choice for On-road & Off-road travelling. Highways, gravel roads and dirt tracks are easily handled by the appropriate choice of Steel Belted Radial tyre.
    Off-track 4wd work requires stronger tyres, All Steel Radials and Bias Ply tyres are the best tyre alternatives for these conditions. Both have heavy thick sidewalls that go along way to resisting the stakes you will eventually become very familiar with.

For anyone considering Off-track 4wd work -
    1) Keep in mind that your tyres will have to get you home after the trip as well as survive the trip!
    2) Tyre technology has advanced in the last couple of decades. Mother nature does not really care about technologically advanced tyres.

STEEL BELTED RADIAL TYRES (S.B.R.)

    The most common of all tyres today, 98% of 4WD tyres on the road now are Steel Belted Radials. This includes famous 4WD tyres such as All-Terrains, Coopers, Wranglers, Duellers, Road Grippers and dozens of others.
    S.B.R 4WD tyres are the best compromise for On-road and Off-road work. Steel plies under the tread of the tyre give strength and rigidity for high speed On-road travelling, while also giving the ability to bend and grip reasonably well while Off-road.
    The sidewalls are thin and supple, allowing little heat build-up at high speed thus reducing tyre wear. These same thin sidewalls can also be used as shock absorbers for Off-road. By letting your pressure down a few psi, the tyre will absorb many of the corrugations and potholes with ease. Most importantly it should reduce the risk of damage, as the tyre with less pressure will "give way" so an object won't damage it, (try popping a half flat party balloon). This makes travelling much more comfortable and less strenuous on the suspension and chassis of your vehicle.
    Better built 4WD Steel Belted Radial tyres have extra plies in the tread or sidewall, allowing them to be used in more serious conditions off-road.
    There are both Tubeless and Tubed SBR tyres. Many sizes and widths are available and the variations in tread pattern will give you nightmares. In the last few years the manufacturers have begun to label 4wd tyres so we can easily see which tyre works best in what conditions.

So now we have 3 basic types of Steel Belted Radial 4wd tyre

    · H/T - Highway Terrain = 90% On-road/ 10% Off-road
  These tyres look similar to a normal car tyre, for high speed and comfort.

    · A/T - All Terrain = 60% On-road/ 40% Off-road
  General-purpose 4wd tyre, the best compromise for On-Road noise and comfort & Off-Road traction and durability. The majority of 4wd tyres are A/Ts.

    · M/T - Mud Terrain = 85% Off-road/ 15% On-road
  Specific tyres for maximum traction in rough, wet, steep & rocky conditions, they have aggressive tread patterns. M/T tyres are designed for mostly Off-Road use.

    The commonly available Steel Belted Radial tyres easily handle the vast majority of 4wd work; regardless of brand or width they will do the job for you. Normal Off-road work is quite within the capability of these tyres, whether you are rattling along the "Gunbarrel Highway" on those mongrel corrugations, creeping down a track in the Victorian High Country or sand driving on Fraser Island, Steel Belted Radial tyres are just the things.

    However they do have weaknesses.

    None of these tyres have sidewalls strong enough to resist serious damage while travelling Off-track. Due to the construction of Radial tyres the sidewalls are extremely vulnerable to punctures and tearing from stakes. If you intend to do any sort of Off-track work, there are better tyres on the market than Steel Belted Radials.
    Beadell Tours have seen Steel Belted Tyres fail during Off-Track Expeditions. These tyres are not designed for cross-country conditions, no matter what the "experts" or magazines preach.
    Off-track preparation takes time and considerable thought, it is unlike anything you or your vehicles have done previously. Again, please keep an open mind. Ask the advice of people who have experience in this field.

    Being over-prepared in regard to tyres is no bad thing!

STEEL BELTED RADIAL TYRE CONSTRUCTION

ALL STEEL RADIAL TYRES

    A little known variation of the most common Steel Belted Radial Tyre is the All Steel Radial Tyre. Quite simply these tyres have steel plies in the sidewall of the tyre as well as under the tread.
    We mention All Steel Radials in this discussion, as they are the only compromise between Steel Belted tyres and traditional Bias Ply tyres. Apart from that, from experience we can say they work extremely well.
    All Steel Radials are not 4WD tyres. They are Light Truck tyres specifically designed for weight carrying at high pressures in harsh On-road conditions. They have incredible levels of durability due to the stability and strength of the tyre carcass. All Steel Radials are extreme pieces of tyre manufacturing; generally only 12 & 14 ply tyres are available.
    Very few All Steel Radials are on the market at this time. Perhaps only 5 manufacturers produce this type of tyre. MRF, Toyo, Goodyear, Double Coin, perhaps Michelin, there may be others we at Beadell Tours are unaware of.
    From the aspect of a 4WD enthusiast, these tyres are next to "useless" as they are all feature tread patterns for Highway use and only come in traditional narrow sizes. How lucky we are…
    Off-track or "cross-country" work changes the rules dramatically about tyres. Like it or not your "Cooprich" 4WD tyres will not have enough sidewall strength and thickness to withstand the staking and damage sustained during normal off-track travelling. The extra traction of the shoulder blocks now popular with the leading brands is a decided disadvantage as it gives sharp objects a place to lodge and penetrate as the tyre rotates.
    Your best chance is to have nowhere for the stakes to catch onto the tyre, therefore a smooth sidewall offers advantages over aggressive tread patterns. Highway pattern tyres usually have this feature.
    Tyre width is a common debate; the general trend is for a wider tyre for floatation purposes. Most wouldn't realise that "airing down" your tyres for floatation actually makes your tyre footprint longer, not wider as is commonly thought. Next time you are adjusting tyre pressures, do it on a hard surface and have a good look at what is touching the ground.
    In regard to stakes, the less rubber you have on the ground the better. This makes a narrow tyre very attractive.
    From experience Beadell Tours can say that narrow tyres offer little or no disadvantage in regard to floatation.
    Off-Track travelling demands puncture resistance as the number one priority. The reality is nothing else matters when the conditions are at their worst.
    Basically these tyres offer strength and durability well beyond that of normal Steel Belted Radials, and unlike Bias Ply tyres they handle extremely well on the highway in regard to stability, (they are so stiff they corner like low profile tyres!).
    The benefits are simple; All Steel Radials handle well On-road, and won't fail in the sidewall when confronted by a sharp Hakea stump. Always remember you are preparing for the worst-case scenario, you must take every available precaution. All Steel Radials go a long way to ensuring you and your vehicle make it home after the trip of a lifetime, off-track in the western deserts.

BIAS PLY TYRES (Cross Ply/ Rag Tyres)

    Wind the clock back folks; this discussion is about to go back in time!
    Prior to tyres with steel belt in their construction Bias Ply tyres were all that was available. The difference is simple, Bias Ply tyres have no steel in their carcass, and instead of belts or plies of wire they have fibre cords & plies. Traditionally canvas was used, as it was all that was available. With the advent of synthetics all tyres now will have nylon or polyester as the cord material. These "new" fibres are very much stronger than the canvas (cotton) of yesteryear. [Another reason why most tyre sidewalls have got thinner over time.]
    Bias Ply tyres are still being made in quantity around the world. Seeing most use in the developing countries where roads are in disrepair, poor or even non-existent. You can imagine how tough tyres would need to be.
    In Australia we are very fortunate to have an excellent road system by most standards, lets be honest, it's not too bad is it? However Australia is a huge place with a tiny population, we also have some of the most arid, uninhabited country on the planet, 18% of our "island" is labelled as desert. The majority of these deserts are classified as vegetated, meaning they support a great variety of plant life, unlike the traditional desert image of sweeping bare sandhills to the horizon.
    Our conditions alone dictate that our tyres in the outback have to be tough to resist the staking from the scrub, and they are…
    Bias Ply Tyres are still in common use throughout the mining community, Station country, remote area Surveyors and numbers of other professions. It is hard to see these tyres in action as they are used Off-track and don't see much On-road use at all. For this reason most in the 4wd community do not realise that Bias Ply Tyres are still an integral part of Australia's outback landscape.
    Traditional tyres for serious work Off-track were narrow Bias Ply tyres with "Lug" or "Highway" tread patterns. They were generally thick heavy tyres with tough sidewalls, split rims were always the wheel of choice, as they require the least effort to get the tyre off the rim for repairs.
    The lessons learnt since vehicles appeared in the deserts still apply, Mother Nature has not changed, so the gear required to operate effectively in that country is the same now as it was 60 years ago, food for thought.

    Bias Ply Tyres are constructed differently to Radial Tyres. Due to this fact Bias Ply Tyres have sidewalls more resistant to staking and damage than normal Steel Belted Radial Tyres.
    The reason is simple, the layers or plies are laid at an angle throughout the tyre carcass. This means that a puncture will not make the sidewall tear as in other types of tyres. Off-track Bias Ply Tyres are also made in multiple plies, up to and including 16. This gives a tyre an incredible amount of sidewall thickness apart from the design strength. The advantage here is that small stakes will not have the length to penetrate the sidewall, generally snapping off before any damage is done. (Steel Belted Radials are not so lucky, small stakes are just as likely to puncture the sidewall as larger varieties.)
    Bias Ply Tyres in any form will always be better for Off-track work than Radial tyres, a time proven fact. There is a current trend at the moment to use tyres designed for "Rock-Crawling", some of these are Bias Ply type tyres, however they will only be tyres of 6-8 ply in construction. Be aware that they will generally be expensive, difficult to purchase away from Capital cities and normally only appear in "wide" sizes. Not the ideal situation to be in when things are at their worst off-track. But they will last longer than comparable Steel Belted Radials.
    Ultimately the choice is yours.
    The best gear for Off-track work has always been Bias Ply Tyres and Split Rims. Decades of cross-country travelling have proven this beyond doubt. Like it or not the facts speak for themselves.

BIAS PLY TYRE CONSTRUCTION

TYRE LOAD & SPEED RATINGS

    This information came from a few websites. We have listed the tyre ratings for general information. Tyres will most likely have a set of ratings on them somewhere. The load & speed ratings replace the old style Ply Ratings.
    Replacement tyres for a vehicle should be rated for the same load & speed.

MICK HUTTON COPYRIGHT 2004

BEADELL TOURS

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Email : Beadell Tours

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