The sound, the smell, the smoke – there is just something about a two-stroke! And while they are mostly associated with the Motocross world, they’ve always played a special role in the Flat Track scene. Think American King Kenny Roberts, riding a Japanese two-stroke, built by an Australian, to win the Indy Mile; one of the all-time great moments in the sport. And the sensational little smoker in front of you has just the same kind of international flavour, built by a Belgian with a deep passion for turning left and getting sideways. Meet the Italian-American by Jan Van Vijnckt, a once basket case Aermacchi/Harley-Davidson SX250, which has been given the full flat track treatment with plenty of AMF style.
Jan is no stranger to flat track, in fact it’s fair to say he’s obsessed with it, and he’ll go to all corners of the globe to piece together the perfect racer. In the past, he’s resorted to importing a framer-style machine from the US, powered by a Triumph engine and having it shipped all the way to his home in Belgium. And this little piece of interesting Italian-American history arrived to him in a similar fashion, with the Harley two-stroke coming out of a shipping container in parts. Now, most people don’t even know what an Aermacchi/HD two-stroke is, let alone have the ability to build one up from a bitsa.
But Jan’s passion means he’s a student of the game and has the skills to track down hard to find NOS parts and then custom build the rest to create one cohesive custom racer. Once all of the right pieces had been found and others restored so they could be used for the build, things could commence, and the first step was to get the frame right. Fifty-year-old steel isn’t always the best, and because this bike will be raced, Jan gave it a full rebuild and converted everything to be purposeful on track. This means removing any of the tabs and brackets needed for the bike’s street legal components, adding strength where needed and generally tidying it all up.
Then to finish out the full chassis, it was all sanded back and prepared for powder coat, with a chromoly-like finish laid down by fellow flat track fan Bart Verstijnen. Over the top of the sorted frame is the all-important bodywork, it might be minimal, but it tells a hell of a story. The tank is a purpose-built race item, small in capacity, narrow lines and tricked out with a billet filler cap. It’s held on with just two simple fittings, making work in the pits a much easier task. The tail unit is in the signature flat track style, following the lines of the rear hoop to perfection and all topped off with a roughout leather seat upholstered by Atelier Lepez.
But what really brings it all to life is the paint, inspired by the AMF ownership years, the colour scheme has a factory racer vibe, with the design and application brilliantly nailed by another of Jan’s good friends, Richie. Of course, you have to fit number boards, both for the look and for racing and rather than simply zip tying them on, Jan has gone one better. Ultra tidy mounts have been fabricated, with stainless hex bolts and black spacers used to attach the plastic boards. Three are used for the front and two on each side, allowing new boards to be added neatly and easily should the current set get broken.
To get the bike rolling, Jan had previously collected a very special set of wheels to be built up for this very project. The rims are Akront vintage items, a big name in European dirt racing since the ’50s, that is now in the hands of Morad. The front is laced to a discless hub with stainless spokes and then wrapped in a Dunlop DT3 tyre. At the rear, the rim is laced to a quick-change hub, with a Mitas tyre and the factory snail cam adjusters make setting the chain a breeze. “The full disc braking system is custom made, with a vintage Hurst Airheart caliper and master cylinder. I bought these a couple of years ago in America from ‘Donzilla’, a well-known person in the flat track world.”
An engine can be hard to judge purely from the specs, but the 250cc two-stroke is a smooth-revving motor and with relatively high compression, it pulls hard from down low. But one of the most interesting changes Jan has made is moving the shifter to the right side, showing how serious he is about his one-way racing. Some new old stock parts also help to up the ante, with an MX250 piston slotted in and on top there is a Harley spark plug compression release, also taken from the MX250. To improve the timing, HPI ignition has been fitted to provide precise spark control and the heavy weight added as part of tuning the engine
But it’s the sound we’re all here for, and Jan made sure that the entire exhaust, including the expansion chamber, was only the very best. “The exhaust is a custom job also, made by ‘Vanhasselt’ exhausts. He is a guru in making exhaust the old school way, and knows how to make it precise for what you need. A really cool dude that has been in this job for a long time, he taught me lots of stuff about how two-stroke exhausts work.” The mechanical package is finished out with air-assisted front forks and fully adjustable Bitubo shocks, while up on the bars, it’s simply all business. Jan is set to race the bike in the Vintage European Championships, and if his passion is anything to go by, top spot on the podium looks a sure bet.
[ Bike & Photos by Conograph ]