Jack Simpson has been around the block when it comes to racing on two wheels. A former junior motocross prodigy, he notched up multiple national-level podiums in both motocross and supercross before turning his attention to the enduro and desert scene. He won the E1 class of the AORC in 2016 and has since gone on to build a serious off-road resume both in Australia and overseas. Most recently, Simpson raced for the Purvine’s Racing Simi Valley Yamaha team in the US WORCS series, where he clinched the 2023 Pro 2 Championship and backed it up with a third overall in the Pro 450cc class the following year.

Simmo has pretty much done it all when it comes to two-wheel dirt racing, both here in Australia and overseas.

With his American team temporarily folding ahead of the 2025 season, Jack returned to Australia to weigh up his options – and that’s when the opportunity came up to lead the newly formed Winner Triumph Racing Australia team as its premier 450cc rider. Simmo jumped at the chance and quickly shifted his focus from long-haul enduro training to the shorter, sharper, motocross-specific workload needed to be competitive on the national stage. He was a big fan of the production-spec Triumph TF450 straight out of the crate, and it didn’t take long for him to dial in a few key changes to make the bike comfortable and fast enough to run up front at the highest level of Aussie motocross.

When I got word that Jack’s race bike would be available for a test ride, I jumped on the opportunity and started making plans straight away. It was perfect timing – I’d only just thrown a leg over the all-new Triumph TF 450-RC (Ricky Carmichael Edition), so I was keen to see what direction Jack had taken with his race setup. Coming off a couple of years racing international Enduro, I figured his suspension would be plush and on the soft side – but I’ve learned not to make too many assumptions. One of the best parts of riding factory-prepped bikes is seeing just how different they can feel, even when based on the same platform.

Set up time!

Jack Simpson has always preferred a relatively standard setup on his racebikes. In fact, every time I’ve tested one of his machines in the past, I’ve found his ’bar and lever positioning almost identical to my own. He runs the handlebars in a neutral position – not rolled too far forward or back – which meant I didn’t need to change a thing before heading out. The only thing I noticed straight away was how soft the suspension felt, especially the rear shock. I considered adding a couple of turns of preload to lift the back slightly, but I didn’t want to upset the bike’s overall balance. In the end, I decided to ride it exactly as Jack runs it – full Simpson spec.

Ground Zero

For this test, I’d be throwing a leg over Jack’s racebike at the iconic Ride Park circuit near Bacchus Marsh, about 45 minutes west of Melbourne. Normally, when I ride here for a review, the crew has the track prepped, watered and fluffed up – pretty much how it’d look on a typical weekend for the public. But not this time. Anthony and the team deliberately left the track rough and hammered, simulating the kind of baked, beat-up conditions you’d find at the end of a national-level Pro MX round. It was dry, choppy and offered almost no traction – the perfect proving ground for a factory-prepped 450.

The track was littered with bumps of every shape and size, plus deep ruts, square-edge holes and all the hidden booby traps you’d expect on a full-blown national-level motocross circuit.

Firm impressions

At first glance, Jack’s #17 racebike retains the clean lines and corporate finish of the standard TF 450-RC. It runs Michelin tyres front and rear, along with Jack’s preferred bend of Neken handlebar – giving it that factory look and feel you’d expect from a top-level race team. With the walkaround done, it was time to hit the track and see how it all came together.

My first session on the bike kicked off with a couple of warm-up laps followed by about 10 minutes of free riding – nothing too serious, just easing into it and getting comfortable. When you’re swinging off someone’s pride and joy factory racebike, you’re always on high alert. For one, it’s the small, intricate details that separate a full factory build from a privateer machine. And secondly, the last thing you want to do is bin it and have to explain yourself to the rider and the team. So the honeymoon phase is important – you don’t rush it.

Straight away, Simmo’s bike felt ultra comfortable. The suspension was incredibly plush, soaking up all the chattery bumps like a magic carpet. It was only over the big jumps that I felt the bottoming resistance was a bit soft for my weight. The engine felt smooth across the rev range, with a power delivery eerily similar to the stock TF 450-RC. Once I got my head around the setup and picked up the pace, I started to notice a few soft spots in the suspension on the bigger hits – but there’s a very good reason for that, which we’ll get into in the suspension and handling section.

Engine

When I rolled back into the pits after that first session and started chatting with the techs, it made perfect sense why the engine felt so similar to the stock TF 450-RC – because it basically was. Jack’s engine is left in standard trim, with just a couple of small but smart tweaks. He’s switched the final drive from 14/48 to a 14/50 gearing combo for a little more punch off the bottom, and fitted an oversized 270mm front disc for stronger braking performance. Simple, effective mods that keep the feel of the stock bike while tailoring it to suit his racing needs.

The only major piece still waiting to be bolted on was an Akrapovič exhaust system, which the team says gives the engine a slight boost in horsepower right across the rev range. Other than that, Jack was a big fan of the stock Triumph engine, and after a few seasons racing off-road, both he and the team decided against building a fire-breathing race engine straight out of the gate. The standard 450 powerplant is smooth, tractable and easy to ride on a rough track – and I completely get the thinking. Too often we see riders chasing big horsepower builds for the start of ProMX, only to realise they can’t hang on past the 10-minute mark of Moto 1.

Suspension and handling

When it came to handling, the #17 Triumph definitely felt on the soft side – like I mentioned earlier, it was plush and soaked up everything beautifully at around 70% pace. But the moment I ramped it up to full race speed, things started to get a bit dicey. That’s not a knock – it’s just important to understand where the setup was at the time. Simmo had just wrapped up back-to-back seasons racing off-road in the US, where suspension settings are much softer by nature. That was what he was used to, what he was comfortable on, and transitioning to the firmer setup needed for ProMX was always going to take some time.

Since my test, Simmo and the team at Tunetech made two significant suspension changes, each time going noticeably stiffer. The end result was a much firmer package with the balance and compression needed to hold up under the demands of 30-minute motos on brutal national-level tracks. Just watch how the bike is tracking in recent ProMX rounds compared to Round 1 at Wonthaggi – early on, it was wallowing and failing to stay on top of the bumps. Now it’s planted and composed. It’s been a rapid development curve, but one the team and Jack have handled smartly in their chase for race-ready comfort.

What I’d change and what I wouldn’t

While Jack Simpson’s Winner Triumph 450 remains relatively stock compared to full-factory builds like the Monster Energy CDR Yamaha or Boost Mobile HRC Honda machines, it still features some key upgrades and bolt-on parts to both personalise and bulletproof the bike for ProMX-level racing.

It’s always subjective when testing a factory racebike – there’s no one-size-fits-all formula, because each setup is tailored specifically to the rider. What works perfectly for one racer can feel totally off for someone else, depending on factors like riding style, speed, and body weight. In some cases, a factory bike can feel almost unrideable if the setup is dialled too far away from your own preferences.

Thankfully, Jack’s bike wasn’t far off the mark for me. I’m a sucker for big power, so I tend to lean toward the aggressive engine character you’d find in Kyle Webster’s or Jed Beaton’s racebikes, rather than the smoother, more controllable feel of Luke Clout’s or Kirk Gibbs’ machines. Simmo’s Triumph engine was ultra smooth and easy to ride – great for consistency and flow – but I found myself wanting a bit more punch. The suspension had a nice plush action and felt great through the small chop, but could’ve used a bit more bottoming resistance to handle the big hits.

That said, as a whole package, the bike was incredibly user-friendly. For 90% of the riding population, it would be spot on – easy to ride, forgiving, and still quick enough to be competitive straight out of the gate.

I really enjoyed the way the bike felt tipping into corners – it squatted nicely under load, which gave me the confidence to turn wherever I wanted, even in low-traction situations. The Michelin tyres were a standout on the hardpack sections, offering plenty of grip when things got slick. I was especially impressed with the front tyre, which felt planted and predictable across all the varying surfaces we tackled throughout the day.

Summary

The #17 bike has come a long way since I tested it at RidePark. I actually quite liked it in the form I rode – it was clear why the team had taken the direction they did. At the end of the day, it’s all about keeping the rider comfortable and confident, and Jack is a sharp tester with a great feel for bike development. As he’s transitioned back into the motocross rider he once was, we’ve seen his setup evolve accordingly. And like any well-run outfit, the Winner Triumph Racing Australia team has been right there with him every step of the way.

WINNER TRIUMPH RACING AUSTRALIA TF 450-RC

ENGINE

Cylinder Head: Triumph spec

Cams: Triumph

Clutch: Hinson Complete Kit

Air filter: FunnelWeb

Gearing: 14:50

Chain: DID

Bar: Neken

RUNNING GEAR

Suspension: Tunetech

Tyres: Michelin

Exhaust: Triumph (Akrapovič on the way)

Oils: Rock Oil

Seat cover: Strike Seats