We recently settled a fireside debate about which is faster on an overland dice: a small aeroplane or an Isuzu KB. The plane won that dice, but only after the third attempt to land at the Frankfort airport, thanks to adverse weather conditions. However, like all campfire debates, the race inspired some other conundrums of great political and social import. Like if a motocross bike is faster than a bakkie…
Picture the scene: a bonfire in the bushveld. A smartie box of people around said fire in a campsite. They had just received news that, following our highly scientific research, a Cheetah 912 plane had beaten the Isuzu KB300 D-Teq 4×4 hands down on a cross-country dice. The silence didn’t last very long, of course. “I’m not the type of person who says ‘I told you so’,” began the party who had begun the debate, several months ago, with a half-empty glass of courage in the right hand and a half-smoked Camel in the other. “But I told you so.” The man who had previously attempted to simulate the sound of a microlight (but who had more resembled a giant, inebriated bumblebee), was again sounding, well, inebriated. “You have to remember: it took three attempts for the plane to make the trip. It can only fly in perfect weather. The bakkie can drive any day, in any given weather conditions. That little plane will go only one way when there’s a big storm or a tornado or a hurricane. And that’s down…” He followed this up with a dramatic impression of a plane falling out of the sky, while he yelled rather loudly over an imaginary microphone: “Mayday! Mayday! I’m going dooooooown!”
Finally, and maybe fittingly, the unsteady-on-his-feet lad crashed face down in the dirt, uncomfortably close to the fire, his Castle Lite beer still magically clutched in his hand, the right way up. The Airwolf couple from Modimolle was there, too. The middle-aged man, who can so eloquently copy the clap-clap sound of a Huey helicopter, was in a more pensive mood. “Jissie. So the plane actually won…” He was quiet for a long time, staring at his compatriot lying next to the fire with his face in the dirt, the beer still unharmed in the air in his right hand. Then, as if he had just had a momentous, angelic vision, he stood up from his camping chair: “I bet a motocross bike will also beat the bakkie!” The party who had started this whole debate in the first instance added some high-octane petrol to the proverbial fire: “Bah! A motocross bike? The bike may be faster on a very technical, tight motocross track with big jumps. But in the faster stuff, like on a fast MX track, the bakkie should have the edge,” he said. “Mayday, mayday…” mumbled a creaky voice from next to the fire, the precious beer in exactly the same position it had been for the past few minutes. Clearly, this required another highly scientific experiment to settle the debate: is a motocross bike faster than an Isuzu KB300 D-Teq 4×4 double cab, or not?
Clearly, a standard bakkie stands absolutely no chance against a right proper moto-cross bike on an MX track with 10 metre-high jumps, 50 metres of relentless ruts, berms that are just wide enough for an MX bike, and so on. We needed something a bit more fair. We settled on the international standard Legends MX track at the Rhino Park complex, east of Pretoria. This 2.4km track is fast and reasonably flat. There are still a few jumps though, so killing a standard Isuzu KB was a very real possibility if due care was not taken. A hardcore cross-country rally car with a spaceframe and R500 000 suspension set-up may be right at home on those jumps. A stock double cab bakkie… not so much. But the MX track was just one of the cunning tests we devised. We included a 400m gymkhana on the McCarthy 4×4 Club’s famous sand section, also at the Rhino Park complex. Lastly, there was a straight time trial over 400m, on a dead-straight section of gravel road, next to the aircraft runway at Rhino Park. Between the three tests we would be able to settle the debate, we reckoned. Next we needed a bike.
Sean Nurse is Caxton Local Newspapers’ motoring supplement editor. Called, Autodealer, it is distributed with The Record community paper, reaching millions of readers across the country. Sean also happens to be an ace racing driver, often beating his big-on-ego motoring scribe colleagues in a most humble, unassuming fashion. He is a keen motocross rider, and he owns a Yamaha YZ 450F that he rides as often as he can. Knowing Mr Nurse, he may not talk up his chances of beating the bakkie, he’d just get the job done. We’ll soon find out how fast (or slow) the bike proved to be, but we need to add some perspective here, too. Asking how fast (exactly) an MX bike is in a straight line is like asking how long a piece of string is: there are many variables in determining the speed, such as the size of the sprocket and the size of the wheels. Sean’s YZ 450F still uses a carburettor, but on the new models with fuel injection, one can even select specific engine mapping for specific tracks, so you can select a map for a fast flat track, or one for a more technical one with big jumps, and so on. Ultimately it depends on set-up and specific requirements. For this test though, the Yamaha arrived in the same state in which Sean uses it to play over weekends. So no fancy sprocket tricks or different wheel sizes to increase top speed: what you see is what you get. For interest sake, with the appropriate gearing and tuning and whatnot, YZ 450Fs have recorded top speeds of around 160km/h.
The Isuzu KB300 D-Teq 4×4 double cab used for this test is the very same that took our international correspondent Robb Pritchard through Lesotho (on some rather extreme 4×4 tracks, too), it competed in our #Fast Bakkie challenge, and it raced against the Cheetah 912 plane. It has been around the block. The KB is still as solid as the first time we drove it, many months ago. Indeed, compared directly against some of its newer competition, the Isuzu may not be quite as fast around a rally track, but it is as tough as nails. This is a good quality to have, especially considering it would be required to take on an international-standard MX track. With jumps. The KB300 D-Teq’s four-cylinder turbodiesel engine produces 130kW of power at a relatively low 3 600r/min and 380Nm of torque, peaking at 1 800r/min. The test unit was equipped with a five-speed manual gearbox, which is more suited to the task at hand than an auto shifter, of course. The KB comes standard with traction and stability control, which can be switched off completely. Also counting in the KB’s favour are the standard General Grabber 18-inch all-terrain tyres. The more chunky tyres would, theoretically, add some extra grip to the equation.
Of course, the Isuzu’s four-wheel-drive system would help… with four wheels providing traction, instead of just one, we reckoned it would fare better at blasting out of the corners. That said, there is the small matter of weight difference. The Isuzu weighs nearly two tons, while the Yamaha tips the scale at just over 100kg. The bike doesn’t have to slow down for the jumps either. We resisted the temptation of asking nine-time World Rally champion Sébastien Loeb to drive the KB for us. Instead, we decided to keep it local, and real. So Average Joe Sean Nurse was on his YZ, and Average Joe Danie Botha was in the KB. Both Average Joes have a good measure of motorsport experience though. As they say in the classics: let the games begin…
The Isuzu took to the sandy tracks first, at Sean’s request. Sean, cunningly, hoped that two runs in the bakkie would smoothen the route for his Yamaha. We deflated the KB’s all-terrain tyres to 1.8 bar. This, we hoped, would be a good compromise between flotation on the sand and not so much chance that a tyre may depart from a rim (as happens when the tyre pressures are too low and you press on). Off we went, in four-wheel- drive high range. With the Isuzu’s five-speed gearbox, we didn’t bother with swapping gears, sticking to first only for this slow speed test. The KB did a grand job though, and stopped the clock at 00.58.45 seconds. The second run was slightly better, at 00.58.32 seconds.
Sean and his noisy YZ 450F were next (mind you, we’ve never really come across a motocross bike that isn’t noisy). Watching Sean power through the sticky sand it was clear that riding a bike in such sand is a heck of a physical workout; the front wheel needs man-handling and a wide open throttle to prevent a faceplant in the sand. Finally, the Yamaha roared over the start/finish line: 00.57.06 seconds. He had beaten the bakkie by a rather narrow margin, but our offer to have another go was met with heavy breathing, interrupted with a few words: “I… need… to save… my… energy… for the… other… tests.” We jumped into the KB, switched the air-conditioning back on, had a swig of water, and headed over to test No 2: the MX track.
The MX track
On our first sighting lap, the length of the track really surprised us and Sean, mounted on his noise-generating apparatus. Also surprising was the apparent speed of the track: there are a lot of flat sections where the Isuzu could build up some gas. However, there were also a few crests that needed a careful approach in the KB, otherwise pieces of Isuzu would detach themselves from the bakkie. The bike would have no such issues over those jumps. This is, after all, what it was made for. Sean and his bike were first to tackle the 2.4km track. Although one can’t see the entire track from the starting point, we could certainly follow Mr Nurse’s progress by listening to the Yamaha 450’s noise. After what seemed like a very long time, Sean finally came round the final corner, sliding, clearly hanging onto the throttle cable. His time was 3 minutes 24 seconds. Next it was the Isuzu’s turn, along with jokes from our supportive magazine colleagues that they won’t abandon us, even though the bakkie may require a day or so to complete the same route. Great supporters, they are.
Anyway, with 4WD engaged, and the traction and stability control system disengaged, we let rip. It was soon clear that this was going to get rather entertaining… not quite familiar with the track and those huge jumps, we would come sliding around a corner, only to be confronted by a steep drop in elevation. This would induce stomping on the brake pedal, followed by a terrified yelp from the driver, a spectacular slide (as observed from the outside, at least) and
successful clearance of the dip. This situation repeated itself about eight times on the lap. On a few occasions, the Isuzu became quite airborne. Apparently the motocross clan call this ‘scrubbing a jump’; when you take a jump but deliberately keep the height of the jump down. Er, yes, that’s exactly what we were doing. Scrubbing the jumps. Finally, we shot across the finishing line: 3 minutes 43 seconds.
This margin, which was much closer than anyone would have guessed, clearly did not impress Sean. So he went out for another run. This time, with a better idea about the track, we could hear the Yamaha make even more noise than usual. Mr Nurse was clearly ‘pinning it’. That’s another bit of motocross slang for you, meaning his throttle was wide open. Exactly 3 minutes and 12 seconds later, he blasted across the line. Now, since he had improved his first time by 12 seconds, we felt it was necessary for the Isuzu to also have another shot. Especially since we had a much better idea where those drops, dips and whatnots were. Off went the Isuzu again, the four-wheel drive affording it more grip out of the slow corners. At one stage we even hooked third gear before throwing the KB sideways into a slow corner, back in second gear. This time round the amount of panicked yelps in the cabin was kept down to just three. With much vigour, the KB eventually flew across the finishing line. The time? Three minutes 24 seconds. It had matched the YZ 450F’s first run, but was still 12 seconds behind. And that stage we thought it best to quit while Sean’s bones were all intact, and the Isuzu had all its plastic parts.
This was a straight dice against the stopwatch. Starting on the gravel track, both vehicles had to accelerate as fast as possible to reach the 400-metre mark as quickly as possible. Now, as mentioned before, the speed of a motocross bike largely depends on its gearing and its wheel size. Top speed can range from 100km/h to around 160km/h. Sean reckoned his bike would reach about 120km/h in fifth gear before hitting the rev limiter. This sounded like great news for the Isuzu. Finally its higher top end would count in its favour. That is, until we realised that the Yamaha would need less than 100m to reach that speed. Cor blimey! The YZ 450F went first. Mr Nurse moved his weight as far back as possible, getting the most of it over the rear wheel to enhance traction; and what a holeshot he got, that noisy single cylinder engine making a huge racket as it blasted off the line.
Baarp. Baarp. Baarp. Baarp. Baarp. 00:00:17 flat. That seemed like a very good time. The Isuzu would be able to reach more than 120km/h in the 400-metre sprint so, theoretically, we thought we had a shot. A slim one, but at least there was a chance. Three, two… one… go! The call came over the two-way radio, and the Isuzu also got a good start, the four wheels just briefly spinning (with 4WD high range selected) before running out of revs in first gear. Second gear. Third gear. The speedometer swung past 120km/h… and across the line! 00:00:21.2. Bugger. The fact that the bike reaches its top speed so quickly had negated any higher top speed advantage the Isuzu may have had. So that was 3-0 in favour of the noise machine. Bugger.
The highly scientific conclusion
Okay, the Yamaha YZ 450F was faster than the Isuzu KB300 D-Teq 4×4 in sand, on an MX track and over a 400m sprint. Yes, in its own backyard, an MX bike is faster than a bakkie. But when all is said and done, and we all headed home, the Yamaha had to be, with some difficulty, loaded upon a bakkie’s bak, and transported home. The YZ 450F doesn’t have a light, mirrors, indicators or even a speedometer. It’s as illegal to drive on public roads as is a wheelbarrow fitted with a 250cc two-stroke motor. In the Isuzu cabin there are leather seats, air-conditioning and a modern infotainment system with satellite navigation. It’s all plush and quiet and, compared to the bike, rather refined.
Consider: the bike’s fuel tank can swallow just 6.8 litres of petrol, and offers a range of about 50km if the rider hangs on the cable. Even a ride between Johannesburg and Pretoria may be a bridge too far for the Yamaha to cross on a single tank. The Isuzu can reach 700km. Fair enough, one can’t compare apples with grapes. In conclusion, a great compromise: buy a Yamaha YZ 450F, and transport it on the ‘bak’ of your Isuzu KB to that MX track. Then you have the best of both worlds. We will shortly report our scientific findings to our camp-fire compatriots. But we have a feeling it’s not the last time an Isuzu bakkie will feature in a “faster than…” test.
2007 Yamaha YZ 450F
Engine One-cylinder petrol, four-stroke, liquid cooled, DOHC
Power 50kW @ 9 000r/min
Final drive Chain
Front suspension Upside-down telescopic fork
Rear suspension Swing arm
Seating capacity One
Dry weight 100kg
Fuel tank 6.8 litres
Range Approx 50km
Price R114 950 (new, with fuel injection)
Isuzu KB300 D-Teq double cab 4×4
Engine Four-cylinder turbodiesel
Displacement 2 999cc
Power 130kW @ 3 600r/min
Torque 380Nm @ 1 800r/min
Transmission Five-speed manual
4×4 system Part-time (2H, 4H and 4Low)
Driving aids Traction and stability control, rear differential lock
Seating capacity Five
Consumption 10.1 litres/100km
Range Approx 700km
Price R549 800
This feature would not have been possible were it not for the following people and venue:
• Shirley Phalane, Yokohama Driving Dynamics – as always, Shirley went above and beyond her duty to organise the Isuzu KB for us on behalf of General Motors SA.
• Sean Nurse, who piloted his own Yamaha YZ 450F.
• Tinus Breitenbach, manager of the McCarthy 4×4 Club, who was also our independent (and very strict) timekeeper (mccarthy4x4.co.za).
• Legends MX. More information: [email protected]; Tel: 083 413 7726.
Text: Danie Botha Photographs: GG van Rooyen