Transmoto - Salt of the earth

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F E AT U R E

EARTH Salt of the

Nigel Petrie had no plans or designs; just a burning desire. Transmoto’s Ben Dillaway discovers how this ingenious fitter-and-turner for Ford transformed a well-used KTM 350SX-F into a sleek salt racer that set an Australian land-speed record this year.

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BEN DILLAWAY SIMON DAVIDSON // NIGEL PETRIE // DEAN WALTERS

he world is racing past Nigel Petrie as he hurtles towards the horizon. He clicks fifth gear after the first mile, and has four more miles to hold it flat.

The KTM 350SX-F engine, sitting only centimetres from his chest, is screaming and giving all it’s got. Nigel’s helmet is nestled against the frame he’s custom-built, and the 32-year-old is feeling every vibration as he flies across the salt of South Australia’s Lake Gairdner.

His vision is blurred, but he knows he just has to keep it pinned until he reaches the five-mile mark.

Nigel has just completed his first

run at the 25th annual Speed Week earlier this year. The ‘salt bike’ that he conceived and created in his shed at Geelong in just two weeks, performed and held up just as he’d hoped. He doesn’t know it yet, but on that eye-watering first run he set a new national land-speed record for a 350cc motorcycle, clocking 122.37mph. That’s 196.93km/h.

So, how on earth did he transform an ordinary KTM 350SX-F into the machine you see on these pages?

It all started with the simple question that every two-wheeled junkie asks of his bike: how fast can this thing actually go?

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BIKE DISSECTED

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THE BUILD It was late 2013 and Nigel, who grew up racing motocross, wanted to get back to his dirt bike roots. The fitter-and-turner, who works for Ford Research and Development doing prototype machining, bought a 2012 KTM 350SX-F and hit the trails and local motocross tracks.

“I was so impressed with the 350; it blew me away,” he recalls. “But something was always on my mind – how quick could it go?”

A year of trailriding around Victoria and 68 hours on the engine later, it was a question that persisted. Nigel couldn’t shake it and needed an answer. After much thinking and searching, he came across land-speed racing and the Speed Week event.

“That sort of got me thinking,” he says. “I wondered if this was something we could do as a project?”

Nigel had just finished building a drift ute and was itching to get back in the shed: “Everything was sort of settling down so I wanted to keep the momentum and projects going.”

The ute build was captured by close friend and filmmaker, Matthew Cox, who made it into a documentary any motorsport fan would love. The

pair decided a trip to Speed Week would be the perfect plot for another movie. They’d film the bike’s build, the journey there and, of course, the action on the salt. At first, Nigel planned to ride in the production class at Speed Week, but that quickly changed. After reading the rules, he decided to go all out and create something for the special construction class.

Nigel’s idea was to create an all-new chassis, but one that’d still house all of the original KTM components; an idea inspired by a photograph of a Revell Triumph Vintage Dragster hanging in his garage. “It wasn’t until I started looking into the early drag race scene from the ’60s that I really got an idea for the style I wanted,” he explains. “Those guys were really on the cutting edge in the way they built their chassis and everything. What they did back then was pretty wild. I wanted to capture a little bit of that essence, and put a modern-day spin on it. I basically wanted to take all of the factory components off the KTM and turn them into something that would look like it’s from a different era.”

Even though the idea of what he wanted to create was crystallising in Nigel’s mind, a big piece of the

BIRTH OF A CONCEPT

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f you plan to set a land-speed record, a dirt bike powerplant probably wouldn’t top most bike builders’ list. So, why did Nigel Petrie use a 350SX-F donk?

The 32-year-old reflects on how the idea came to him...

“I spent a lot of early 2015 on my KTM 350SX-F, blasting the firetrails of the Victorian Alpine Region. It was a simple pleasure and the break I needed at the time. One morning, I was stretching the legs of my KTM, impressed with its ability to accelerate so hard that you could carry the front wheel basically till

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the rev limiter in top gear.

“Back at camp, I started to contemplate how fast a 350cc motorcycle could actually go; how to find a road long enough to figure out what the tallest possible gearing would be; the point at which the torque would limit the speed. I downloaded data for the 350SX-F’s internal gear ratios, measured the rear tyre’s rolling diameter, then selected the tallest gearing that was able to fit on both the rear wheel and the drive sprocket. And, after a few minutes on my iPhone, I was able to extract some numbers.

“Without real-world resistances, I worked out I could extract 250km/h at the rear wheel, which is pretty impressive from a 350cc single cylinder! That night, it consumed my thinking. How much wind resistance would be holding the bike back? Would the engine stay together long enough to get to that speed? How would I find a road long enough to truly find out?

“The next morning, I filled the bike with fuel, checked the oil, fitted a clean air filter then headed out to the forest. I’d found a fire trail the previous day that was wide and

smooth and, if I got a run up from the road and hit it as fast as I could, I knew I could get a pretty good idea of what this gearing was capable of.

So I tightened my helmet, looked down the track, and hit it! Ducked down in top gear, there was still a lot of wheelspin so I moved my weight further back and kept the throttle pinned. I didn’t find the rev limiter on that run and decided to back off because I could see the end of the trail.

“That night around the fire, I reflected on visiting a salt lake with my parents as a kid and,

after a quick search, I found a group called the Dry Lakes Racers Association and their records for the fastest runs ever made in Australia. To my surprise, the production bike record for the 350cc category was only 85mph (136km/h) and I knew I could improve on that. So I looked further into the event, the conditions and the rules. I downloaded the rulebook and started thinking about how I could get there; to do it on a budget, and to maximise my opportunities by doing it in the most valuable way possible.”

BIKE DISSECTED

“It all started with the simple question that every two-wheeled junkie asks of his bike: how fast can this thing actually go?”

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puzzle was missing – the approval to film on the salt flats for two days after Speed Week.

“We thought if we’re going to do it, we’re going to do it properly.

And if we’re to do it properly, then we need time on the salt after the event to get all the footage we need,” explains Nigel.

The duo applied for permission to film three months out from the event, but the approval didn’t come through for two months. And that left them just one month. “Until we got that result back from the government, the project really wasn’t going to go ahead. I had all the ideas,

but it wasn’t until the authorities said yep that we decided to pull the trigger on it. So I really only had two weeks to build the bike!”

With the clock ticking, Nigel embraced the challenge. He saw the race against time as an advantage. “I’m glad I stalled the build and packed everything into a tight timeframe,” he says.

“Otherwise, I may have overthought a lot of components.”

Nigel didn’t draw up any plans for what he was creating. Instead, he dissected the KTM 350SX-F, set up a jig to hold the engine, used alloy filler rod to lay out the chassis, and

started welding the $300 worth of chromoly tube he’d bought.

“The bike literally came to life in front of me,” he says, reflecting on that day. “I didn’t draw or plan anything; I had a wheelbase, a motor position and a heap of ideas.

But that’s it. I couldn’t see many issues with building a bike that was fairly low-slung with a pretty long wheelbase and kind of stiff rake. How could that go wrong? I knew it would flex a bit, but I was all about making it light, and just putting the essentials in. The rest was really just adapting it to my body. My arms and legs all had to be sort of tucked in. The seat area

had to be as skinny as possible. It was all just about making my body fit the bike, so that was really the deciding factor on the wheelbase, and how everything sat.”

Over an agonising two weeks, the ‘salt bike’ was born in Nigel’s shed.

“It was a pretty simple project, but I put a lot of hours into it. I sacrificed and neglected every other thing in my life to get it done,” he concedes.

He completed it after a building bender that started on a Friday afternoon and finished on Sunday.

“The bike looked perfect. Surreal,” he says, “There was nothing I wanted to change and nothing it compared

“Nigel didn’t draw up any plans. He had a wheelbase and motor position.

He dissected the KTM 350SX-F, set up a jig to hold the donk in place, and started welding.”

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to. It blew me away that just two weeks beforehand, it was the perfect bike for hitting big jumps on a supercross track.

I’d spent a lot of time with this machine as a dirt bike, and essentially it’s the exact same bike. It’s just all laid out a lot differently now. It’s hard to believe it’s nearly all stock motocross gear.”

“The essence of motorcycling is getting out there and getting the wind in your face and seeing lots of different sights and just having a good time on two wheels. That’s really what we were looking for, and that’s what we got by riding to the salt. The salt racer travelled in the back of the van.”

THE JOURNEY

SPEED WEEK

Nigel’s original idea was to ride his KTM to Speed Week, pull it apart once he got there and then assemble the salt racer. “The initial idea was to basically ride the bike to South Oz, get the record for the fastest 350cc, and then ride it home again. The whole concept was for me to come back from the salt and then remove all of those parts back out of that frame, put them back into my dirt bike frame and basically be back hitting the trails again within just a couple of hours,” he says, amusing himself at the thought.

However, once things ‘escalated’ with the build, the plan changed. He ended up buying a second 350, which he rode to Lake Gairdner, and to have on hand for spare parts if needed.

“The build was fun, but it’s not the essence of motorcycling,” he says.

As you’d imagine, Nigel’s bike turned heads at Speed Week. The desert dwellers were mesmerised by its sleek design and contemporary styling. “It was like nothing they’d ever seen,” recalls Nigel. “They quizzed me about how many years that I’d been building it for, so I felt a little bit silly saying, ‘Oh, just under two weeks.’ They kind of didn’t take me seriously to begin with.”

While the old salts were in awe of his creation, it was the vast and endless space of Lake Gairdner that captured Nigel’s attention. “It doesn’t dawn on you until you get there – until you look out over the horizon and see the curvature of the Earth – that you realise you can basically go as fast as you possible can. There are no bumps and nothing to hit. It’s just dead flat for as far as your eye can see.”

BONNEVILLE

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he Bonneville Salt Flats in northwestern Utah in the United States are the spiritual home of land-speed racing, made famous in more recent years by the movie, World’s Fastest Indian. And it’s where Nigel Petrie is headed next.

After conquering Australia’s Speed

Week on the salt flats of South Oz’s Lake Gairdner, his mind is already focused on the infamous Bonneville salt.

“I really want to go over to America and do something very similar to what we did here,” says Nigel, “so I’m looking at

building a fresh chassis in Australia and taking it over in a surfboard bag. Having thought about everything that I made and built for the Australian journey, there are ways and bits and pieces that I know I can change to go faster in America. The aim would

really be to build something that would be capable of 150mph, with the same motor. I’m pretty confident I can build a bike that’s going to do the job a lot better than what we did in Australia.”

And while it sounds like more of a mission, Nigel believes flying to

Bonneville will be easier than the roadtrip was in Oz: “In many ways, Bonneville is a lot simpler to do, because Lake Gairdner’s Speed Week is just so remote. A plane trip to America is a lot easier than driving a whole crew to the middle of the South Oz Outback.”

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During the event, Nigel did 20 runs and about 30 more while filming when they had the salt to themselves.

“You basically just bang it through the gears,” he says, his eyes lighting up at the memory. “It’s almost like you’re on a dyno, because nothing is moving.

You can see the horizon is changing slightly, but there’s really nothing moving. There are no trees buzzing past. There are a few witches’ hats that roll past every now and then, so you really have no idea of how fast you’re going. You can’t even really see where you’re going, but you know that you’ve got to stay within the witches’ hats,

hold on, and just go as fast as you can.”

Out of 50 runs he did, Nigel’s first turned out to be the fastest, recording a speed of 122.37mph (196.93km/h).

In his subsequent runs, he could only manage 117mph (188km/h) but, finally, he’d been able to answer the question that crept into his brain a year earlier and wouldn’t leave.

“I had no idea what speed the bike was going to do,” he admits. “I basically wanted to break the 100mph barrier, and then go from there.”

Well, he did go from there. A fair way too! And aside from answering that niggling question about his bike’s

top-speed, he answered another question in the process: how much it could take?

Just as they were finishing filming on the salt two days after Speed Week, the Kato’s engine finally gave way.

“The big-end bearing let go and it seized,” he says, almost as if he didn’t expect it to get that far given the abuse he’d thrown at the thing.

Some might see it as a poetic end to the project, or just the reality of

“I’d spent a lot of time with this machine as a dirt bike, and essentially it’s the exact same bike. It’s just all laid out a lot differently now.”

FLATS MOVIE

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he story told on these pages will soon be the subject of a documentary film. From the moment Nigel Petrie decided to test the capability of his KTM 350SX-F, he decided to work together with his good friend and filmmaker, Matthew Cox, to capture the entire project on film. The plot for the doco was

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simple. “Finding the ultimate road where you can really stretch a bike’s legs and find out what it’s capable of,” explains Nigel. “As we decided to make a documentary from the beginning, everything was done with the movie in mind, and we put a lot of time and effort into doing everything properly,” he says. “That includes

re-designing the shed to give a backdrop to the build, and using smoke machines in the garage to get a bit of moody grain into the film. It all seems a bit silly when you’re doing it, but the film is going to be payback for all the hard work we’ve done.”

Visit www.flatsmovie.com to sign up for the movie.

a bike that already had 68 hours on it before being held against the rev limiter over and over.

“Everything goes to the salt to die,” Nigel says, philosophically. “It’s such a harsh environment out there.

I definitely pushed the bike to its limits. The fact it lasted that long is a testament to the incredible durability of this dirt bike and the amazing engineering that goes into making dirt bikes run so well.”

LOG ON TO For more behind-the-scenes images of this ingenious build, and a link to Flats Movie – the film made about the project’s build and subsequent salt-racing success at Lake Gairdner’s Speed Week.