Building a high-caliber race bike starts with the addition of race-grade, bespoke and aftermarket components, though it’s the countless hours of expertly dialing each element in that really separates pro-level racers from the rest. And that’s exactly what we’ve got here, a professionally-built competition machine from Mike Hill of Survivor Customs.
This one-off tracker is built around a 600cc Rotax that’s been wrapped in a heavily modified chromoly ATK chassis (utilizing the existing oil tank, top and downtube). The Austrian two-cylinder now inhales through a 40mm pumper carb and spits burnt fumes via a trick one-off two-into-one exhaust with stainless headers and a titanium link pipe and muffler.
The suspension on the Rotax-powered racer is comprised of late-model Yamaha R6 forks and a custom shortened swing-arm (side-mount monoshock) unit off a Vertemati. The dirt track racer now rolls along on a set of Talon rims with stainless spokes. Mounted atop the custom chassis is a custom alloy fuel cell housed in a fiberglass shell, while out back one of Survivor Customs’ Tracker-style fiberglass tail pieces was dropped into place and capped out with a handmade seat comprised of “reclaimed leather”. The racer is also sporting a pair of SC’s fork guards.
Not only was this very example piloted by Mike Hill to two DTRA (Dirt Track Riders Association) Thunderbike championship titles, it’s also been featured in (the #34 issue of) SideBurn Magazine. This tracker was also featured on the official poster for the (DTRA) 2019 Flat Track Nationals, and was displayed at various The Bike Shed shows. You can check out photos of the build process on the SC Instagram page.
You can find this custom Rotax-powered Thunderbike tracker for sale here on TheBikeShed with a price of $7,250 (or £5,500, marked down from £6500) in Newcastle upon Tyne, England.