In June of 2013 we published in this BLOG our views on what should be done to enhance rider safety with ATVs with a 10 point message. It’s good reading and smart practice based on years of personal experience with the machines, on the farm and in the workplace and analysing the accident reports we see. If you scroll back through our posts you’ll find it. At that same time we also stated that we were against ROPS (Rollover Protection Systems). That opinion still stands for fixed or rigid applications, because if the bike goes over, that steel tube landing on you will likely do more damage than if it wasn’t there.
happy new year 2018 images
A much better way to approach the thorny issue of rollover protection is this brilliant Kiwi idea called the “ATV Lifeguard”, marketed in Australia by ATV goods supplier Topaz Global in WA. The Lifeguard is unique in that its safety “halo” is a segmented plastic vertebrae with a central tensioning rope (or its spinal core) that allows the Lifeguard flexibility if it were to land on you. Whereas a rigid tube will hurt, the Lifeguard will deform around your shape. Bruised you might be, crushed you wont!
It’s brilliant and fitted currently to one of our Yamaha 450 Grizzlys with an easy installation, it’s demonstrating to our many course attendees who ride the bike how safe things can be if only a bit of thought is put to the problem.
Craig from Topaz Global delivering our ATV Lifeguard
Lifeguard fitted to Grizzly, a smart package indeed!
South Australian Government in the delivery of its services in the Outback is now using the “poverty-pack” Toyota 200 Series wagon in increasing numbers. It’s a good wagon choice, bristling with driver safety electronics and 4WD systems that make it easy for drivers to stay out of trouble. However tyre fitment from the showroom floor leaves a lot to be desired, especially when you venture off the bitumen.
Standard 200 rubber is a Japanese Dunlop Grandtrek AT22, a ‘Passenger’ car (P) construction making it a breeze around the city but quick-wearing, flimsy and puncture-prone in the bush. The size is a little problematic too, because lots of old bushies will confirm that the wider the tyre, the more it becomes a ‘puncture-magnet’. Nothing we can do about that, because tyre and wheel sizes these days are regulated by manufacturers and legislators and deviating beyond a very narrow range of alternatives might bring trouble of a legal kind.
Let’s analyse the size and purpose:
285/65R17 116H = 285mm wide, with 65% aspect ratio (sidewall height), R = radial, fitted to a 17″ diameter wheel, with a 116 load index (1250kg carrying capacity per tyre) and H speed rated (210kph maximum speed)
This is a high-speed tyre (designed to run to 210kph in a country where the usual maximum is 100kph and peaks in the NT at 130kph, it’s ridiculous) designed for an urban existence, with only 9mm of tread depth, with a modest carrying capacity (given the size and weight of the vehicle). If we take a look at who buys 4WDs these days it’s a sad fact that something like 90% of 4WD owners never go bush. Manufacturers knowing that statistic fit rubber better suited to the bitumen rather than the dirt. This means we other 10% of drivers in the commercial ‘real world’ of 4WD will need to seek out something more appropriate.
In the quest for greater durability and longevity the solution will be found in an alternative ‘Light Truck’ (LT) tyre, designed from the outset with a much tougher carcase (more on that below). Now in answer to which pattern should be selected I can say without a shadow of doubt that almost no South Australian Government vehicles will ever require the aggressive pattern of a ‘M/T’ or mud-terrain, but the alternative ‘A/T’ or all-terrain will be right.
An LT A/T will come with a tread pattern that is more open and designed to find grip on loose surfaces. That same tread will be around 13mm in depth, nearly 50% deeper than the standard tyre with a commensurate increase in tyre life. That means significantly better wear rates (i.e. takes longer to wear out) and importantly, much better value for money, for not only are they more durable, but often when you go shopping you’ll discover they’ll be cheaper than the original tyres fitted to the vehicle! Work that one out
The other important consideration with the LT A/T we’d mentioned was the carcase. The only true barometer of tyre strength is the load index. Put simply, the bigger the number the better. We’ve always recommended in the classroom that if you’re replacing tyres for a working 4WD, try and aim for a minimum 120 load index. On some vehicles that won’t be possible, but any increase is good if you intend spending time on the dirt. If we have a look at two tyre makers product lines that we have experience with in here at Adventure 4WD there’s a couple of alternatives that offer far better strength.
Bridgestone Desert Dueler D697 – LT285/65R17 120S – That’s a 120 load index = 1,400kgs and S speed rated = 180kph
Toyo OPAT2 – LT285/65R17 121S – That’s a 121 load index – 1,450kgs and S speed rated = 180kph
Both of these tyres are a more practicable application than the standard Dunlops, so we’ve now got a couple of alternatives to get us started for the bush.
Let’s turn our attention to the ‘nut behind the wheel’, the human interface and managing them correctly.
Consulting the ‘Tyre and Rim Association Manual of Australia’, the bible on tyres and used by both manufacturers, legislators and tyre resellers for determining wheel size, tyre size and pressure, we discover that the recommended on-road or highway minimum pressure for these LT alternatives starts at 250kPa or 36psi for a vehicle weighing up to 3,660kgs. Given that the GVM (gross vehicle mass) quoted by Toyota for the 200 series is 3,350kgs, we’ve got plenty in reserve at this pressure for the bitumen at speed.
So often this calculation is wrong on vehicles we see in here in the classroom, with tyre pressures set ridiculously and erroneously high. The placarded pressures will always be correct for the original tyres seen on the vehicle and should be adhered to. Over-inflating will only increase your risk of trouble with nervous steering, extended braking distances, greater puncture potential and premature wearing of the centres of the tyres, very much false economy if you’ve been guided to seek better fuel efficiencies (over-inflation is often recommended as a way to gain greater fuel economy because of reduced tyre friction/contact with the road surface alas it comes at a cost and with 4WD tyres costing $300+ each these days you’d have to gain a significant improvement in fuel use to offset the demise of your tyres, worn ahead of time).
Taking that 250kPa/36 psi starting point as being right for the bitumen, you’ll need to make some changes on the dirt and employ what we call ‘The 20% Rule’.
The 20% Rule = Reduce pressures by 20% & slow down by 20% on dirt!
If you were barrelling along at 100kph previously, now go no faster than 80kph and only if the road and conditions will support that speed. At the same time a pressure reduction to 200kPa/29psi will give the tyre greater flexibility to absorb impacts with rocks that ordinarily would destroy a tyre.
At day’s end and you return to the bitumen and the speed increases, you’ll need to re-inflate your tyres to their original highway pressure requirement. Do that and they won’t get hot and bothered, because the whole tyre management equation is all about maintaining an effective pressure/load/speed and temperature quotient.
Often you’ll hear the word ‘blowout’ in reference to a tyre failure at speed. This can be a dangerous situation, more likely to occur if you’re not practising our recommendations above. Typically this type of failure happens after a tyre has been compromised on the dirt, a sharp face of a rock or gravel penetrating the carcase/tread and starting a leak. The loss of pressure is determined by the size of the hole, the bigger the hole, the faster the tyre will go down. The penetration may have occurred fifteen minutes, an hour, a day or two previously, but gone unnoticed and with each subsequent minute with less and less pressure the tyre gets hotter and hotteruntil the sidewalls fail. That’s your blowout!
Some drivers can ‘feel’ that loss of pressure and safely pull up before the big event occurs and often with a tyre that’s repairable. Others press on, absorbed in the drive and the need to stay on schedule. A tyre that’s going down will have an effect on the steering, the handling around corners, even braking, it just won’t feel right and will prompt you to check.
Often drivers rely on a visual check, but that’s unlikely to tell what’s going on to all but the very experienced eye. A cheap way to manage temperatures and therefore failures is at every fatigue break you take, walk around the vehicle and put your palm on the top of each tyre and feel what the temperature is like. If one (or more) is substantially hotter than the others that should prompt you to get out a gauge and do a proper check of the remaining pressure, the gauge won’t lie.
There’s other ways of measuring the pressure. Today you can buy tyre pressure monitors that work by sending a radio signal from the wheels via each valve stem of a tyre’s current pressure, to a receiving unit in the car, affixed to the dashboard at easy glance. We’ve been using one in our work vehicle for over two years to really good results. All of these things are good in total loss prevention.
Catch the problem early enough and you won’t have as many dramas. You’ll still have to get the tyre repaired but it might not have caused a loss of control and likely rollover if you’re going too quickly. On the subject of repairs we’re often asked about the merit of ‘plugging’ a hole?
In a word… DON’T!
All too often we see tyres that have been plugged months after the repair was executed and you might say bravo, they really do work. Unfortunately they are only a temporary measure. Forget them at your peril. By plugging a tyre you’ve got no idea what the internal damage might be, nor whether the belt layers have delaminated. Get back on the highway at highway speed and bang!If you’re using them for a quick repair to get you to a service centre as soon as practicable then maybe it’s an immediate solution, but it’s not my preferred option. It’s far better to get involved with the management of your tyres as described above and prevents that puncture in the first place.
In the first instance get the right rubber, an LT is the best bet with the biggest load index you can get for that size. Then manage the pressures correctly, use the vehicle’s placard for the highway and use the 20% rule on the dirt, remembering to reinflate once back on the bitumen. Do these simple things and you can make yourself puncture-proof, we have.
*Footnote – Some might be surprised at the brands we’ve recommended above. In our use these makers products have proven durable on Aussie Outback gravel so we don’t have a problem recommending them. The brands that most often surface in magazines supposedly suited for the bush include Cooper, Mickey Thompson and BF Goodrich. In our experience they should be avoided as their rubber compounds are hard to meet their promise of big kilometres travelled before they’re worn out. What might be good on a USA concrete highway is no good in the Outback and these three will suffer tread chipping, tearing and degradation. Japanese rubber is usually more compliant.
Any time of the year is a good time to have plenty of tread, but in winter never a truer word was said. Tyres and that all-important grip provided mean the difference between getting somewhere or not. One of the great conundrums of 4WD ownership is what’s right in tread design?
Most regular readers of the pages we write either here or in our social media offerings will know of our preference for “LT” or light-truck construction 4WD tyres because their durability and better steerability over standard “P” passenger car rubber sometimes referred to as “H/T” or highway-terrain. Here in South Australia we reckon that LT construction coupled to an “A/T” all-terrain pattern will usually be the best bet. In South Aussie we usually don’t suffer ridiculously muddy tracks, so the benefit of an “M/T” mud-terrain pattern will be largely lost.
In other parts of the country however the muddie might be of benefit, especially in places like the Victorian High Country, where water and hills go hand-in-hand.
Looking at all three patterns it’s pretty easy to see what the design-spec was. The H/T with its regular tread pattern, shallow tread depth (9mm) and narrow tread channels and sipes is clearly keeping an eye on the bitumen. Once it’s exposed to mud it’ll quickly choke and offer zero grip.
The A/T is better placed. With a more aggressive tread pattern with deeper channels (13mm), it’ll swallow and spit out all but the gooiest mud and retain some degree of mobility.
The M/T is really a specialist pattern, big tread blocks with massive voids and deeper channels (13-15mm) get down and bite in the slipperiest, providing important traction when the going is tough.
In terms of road noise the H/T wins hands-down, usually quiet as a mouse, the A/T will be marginally rowdier and the M/T plainly obvious both in and out of the vehicle.
Tyre makers have gone to great lengths in recent years to make noise a thing of the past. Looking at the tread shapes of the latest Bridgestone D697 A/T or their equivalent M/T the D674, or even the Toyo OPA/T 2, their A/T pattern and their OPM/T muddie, the tread blocks are shaped and aligned to ruffle the flow of air through the tread face and create a quieter tyre.
The other issue with M/Ts in the past was wet weather bitumen grip. Having a 2.5 tonne vehicle sitting on big aggressive tread blocks and chucked into a wet corner used to provide some fairly exciting times. Not so now, the more uniform and interlocking patterns afford much greater safety levels than before. They’re not perfect, but as a compromise tyre for tackling difficult trails in wet conditions as well as a run to work or the shops, a modern M/T can work.
No matter what tyre you select make sure it comes with an improvement in “Load Index”. Load Index is the only true barometer for tyre strength and if you can get a 120 loading or greater, you’ve gone a long way to making yourself puncture-proof. You’ll find that mysterious number on the sidewall, seen here in red LT265/75R16 123R. Here’s a link to a site that lists the Load Index amongst other useful information about tyre design http://en.wikipedia.org/wiki/Tire_code
Well we’re in the soggy depths of winter and winter of 2014 has been especially wet in South Australia. With the reservoirs full and the ground sodden any 4WD excursion is likely to be a pretty slippery affair.
Let’s take a look at how you manage those conditions from a driver’s perspective including the obvious and not quite so.
From the driver’s seat the windscreen is mightily important. Without clean glass your vision will be impaired. I’m often surprised at how poor
some drivers let their wipers get before doing something about them. For around $20 a simple and quick fix can be obtained, snapping out the old and replacing it with the new and a clear view of the road ahead.
Additionally with so much humidity in the air it doesn’t take long for the confined space of a vehicle’s cabin to become all fogged-up. Another simple fix that won’t cost you a cent is to use your air-conditioner. Set the vent to the windscreen, turn the AC and fan on to a low setting and recirculate and within moments the interior fog will lift from the windscreen and side windows leaving you again with clear vision. Set the temperature to a desirable level to keep warm without being over-powering (too hot and you’ll likely increase the risk of fatigue on a longer journey – can’t get too comfortable).
Under the bonnet its good policy to keep the windscreen washer reservoir topped-up and with a dash of detergent too, to remove road grime and bug splatters.
On the highway you want to pay attention to how the road has been affected by the passage of heavy transport. In periods of heavy rain water will “pond” in the tyre grooves, worn into the bitumen by constant heavy traffic. That patch will pose a threat to your grip levels and on a bend might mean a momentary loss of traction.
Modern vehicles with ETC (electronic traction control) will be able to respond immediately to the threat, whereas the rest of us will have to make that adjustment by getting off the accelerator for a moment. Heavy use of brakes isn’t advisable either on a non-ABS (anti-lock braking system) vehicle in this situation as the front wheels will lock and render steering non-existent.
In a non-ABS situation you’ll need to employ the art of “threshold” braking (braking firmly but not beyond that fine point of lock-up and maintaining a constant pedal pressure). Of course in an ABS vehicle it’s simple, push the brake pedal HARD and let the electronics work out what’s required.
On dirt it’s really a case of keeping the speed in check. On local dirt that’s well maintained and sheeted with a gravel/metal that offers some grip it’ll be manageable. We have been telling all our clients that 80km/h is the maximum speed on dirt, but that’s only if the road will support it on that day. The real speed will likely be considerably less. What will help enormously is the use of HIGH range 4WD instead of just 2WD on a part-time 4WD and if you’ve got a constant 4WD, locking the centre-differential will help achieve double the grip.
On Outback dirt it gets more complicated because often the road will be clay-based and when wet that’ll become super-slippery. Additionally in desert areas the road often sits lower than the surrounding land, as the road-makers come past annually and flatten the corrugations out but gone down a little deeper each year. In torrential rain those roads become creeks.
Outback roads are closed in heavy rain situations and can stay that way for days after the event. Contacting the SA Department of Transport’s “Far Northern Road Report” is a good way to check on the current state of the network and where you can and can’t go. Here’s the link http://www.dpti.sa.gov.au/OutbackRoads
On any sort of dirt we’re firm believers in the benefits of tyre pressure reduction. On the made dirt roads in good condition that maximum speed of 80km/h might be accompanied with a 20% reduction in pressure from the placarded (the sticker on your door pillar) pressures set by the vehicle maker. This affords the tyre greater impact resistance, meaning less likelihood of punctures and much shorter braking distances coupled to better steering.
If it were really wet on one of those clay roads we often use a 50% reduction in pressure achieving two things, mobility and no track damage. A 50% reduction in pressure needs a 50% reduction in speed though. You’ll need to reinflate to the highway pressures once you resume on the bitumen.
There’s a fair chance too that one day you’ll come across a flooded creek that intersects a track. That is fraught with some peril, and if it can be avoided, do so. It’s much better to suffer the inconvenience of a detour, than never coming home again. If another vehicle can demonstrate that the crossing is possible and it’s safe, then proceed if you must.
Most vehicle makers get pretty nervous if the water depth exceeds axle height. That could be as little as 400mm. You might want to get the owners handbook out to check what they say.
Don’t despair, spring is just around the corner and the promise of some sunshine is near. Drive safely!
December 19, 2013
National Geographic TV in partnership with Land Rover have a great competition on at the moment where you can win your own “Great Escape”, a long weekend away at either The Barossa, Daylesford in Victoria or Noosa in Queensland, with flights, accommodation, dining and the use of a Land Rover all part of the deal. Here’s the link to the competition page http://natgeotv.com.au/win/entryform.aspx?id=150
The concept of Land Rover’s “Great Escape” with Nat Geo is a goodie, a chance to see Rover’s products out and about in some iconic and 4WD locations. There’s three films to view, one shot along The Great Ocean Road, another on Fraser Island and the one that caught our interest, The Flinders Ranges. The films are presented by Nat Geo’s roving reporter Nick Saxon, who’s carved out a career as a singer-songwriter and now as a TV presenter.
Adventure 4WD got involved after we were invited to lend the on-gound support and design a drive route that showed off the Flinders at its best. With a limited schedule of just three days it was obvious we couldn’t get in the middle and wander around the ABC, Chace and Druid Ranges near Wilpena, we needed something closer, so the decision became reallly easy and we opted for the Bendleby Ranges and the superb facilities offered by Jane and Warren Luckraft.
The Bendleby Ranges are the focus of our Weekend Walkabout tag-along 4WD training trips which we offer around 4 times a year during April-November. The driving on the property is awesome, the trails twist and turn following the tortured path of the hills and the creeks, home to the dreamtime serpent story of Arkaroo. The gradients are steep so its a trip with plenty of elevation, LOW range is the go and precision the key. Have a look at our past photo galleries to see what we get up to http://gallery.adventure4wd.com.au/recreational-special-events/ and seek out the pages devoted to “Weekend Walkabout”. For $780 per vehicle (take 10% off if you’re an RAA member) you get 2 days of amazing 4WD’ing, overnight accommodation in comfy shearers quarters and dinner on Saturday night, it’s great value.
The pressure was on back in August as the shoot schedule selected ran right up against the Melbourne 4WD Show. In what turned out to be an epic fortnight for me I had a week’s worth of training leading up to the date, jump on the bird to Melbourne on the Saturday morning at sparrow-fart then back to Adelaide and in bed around midnight, up again at dawn to drive to Clare and meet the crew on Sunday morning and then on to Bendleby for Monday and Tuesday. Of course the balance of that week was hectic too, so no rest for the wicked.
The crew flew in to Adelaide and picked up 2 diesel Discoveries our hero vehicles for the shoot. On Nick’s own admission this was his first real 4WD foray and he can be thankful he got to drive one of the world’s best 4WD wagons, chock-a-block full of technology that makes the job a whole lot easier. Well we bumped across all manner of terrain, up before the sun to capture some great dawn skies, got some big diagonal cross-ups, charged up and down insanely steep hills and had an all-round great time. Have a look at the video shot at the Bendlebys here https://natgeotv.com.au/videos/home-page/land-rover-great-escapes-flinders-ranges-00438058.aspx
Here’s a couple of pics from the shoot.
From left: Nick strumming away atop the North-South Ridge, Navara leads the way, Discos on the trail, “What no phone signal?”, oldie and newbie