The Thunderbike RS-O is a great example of how precise German engineering meets bold custom motorcycle design.
It is built on the Thunderbike RS Racing Series Dragster frame and has a very low, aggressive stance that immediately suggests speed and power. Every detail of the motorcycle is carefully designed, and the result is a custom Harley-style drag bike that looks fast even when it is standing still.
Thunderbike is based in Hamminkeln on the Lower Rhine and is one of the best-known custom bike builders in Europe. Their fame grew after they won the AMD European Championship of Custom Bike Building in 2006 with the “Spectacular,” and again in 2008 with “Open Mind.” Even though these bikes were showpieces, Thunderbike follows one clear rule: every motorcycle that leaves the workshop must be rideable. As an official Harley-Davidson dealer and parts manufacturer, they build most components themselves, making them one of the few builders who can truly create motorcycles starting from the frame.
The Thunderbike RS-O is a complete construction based on the RS Racing Series, which is an evolution of the Dragster frame. The goal was simple: create a sporty, flat and powerful line. To achieve this, the frame uses large-diameter tubes for strength, curved 45 mm downtubes, a strong 70 mm steering head with an internal stop, and newly shaped side sections. The result is a compact and muscular motorcycle with a crouched look that seems ready to launch forward.
The RS-O is powered by a Screamin’ Eagle 103 CUI Twin-Cam engine. This engine gives the bike strong acceleration and the classic Harley-Davidson character that riders love. It uses original Harley injection electronics, so it also meets modern exhaust emission standards. Apart from the drivetrain, almost everything else on the motorcycle is made by Thunderbike themselves. Parts are designed, machined, welded and finished directly in their workshop.
The chassis underlines the performance character of the bike. At the front, a TB-RS upside-down fork with 4 degrees of rake gives the motorcycle a compact appearance and precise handling. Thunderbike also produces the handlebars, grips and front fender. A 130 Metzeler tire sits on a TB Vegas Cut 4.5×18″ wheel, and braking is handled by an ABM radial caliper together with a 300 mm TB-Spoke brake disc.
At the rear, a Tricky Air Ride suspension allows the rider to adjust the height and comfort. The single-sided TB RS swingarm holds a massive 10×18″ TB Vegas Cut rim with a wide 280 Metzeler tire. Rear braking is provided by a Nissin six-piston caliper working on a perimeter wave disc. The tank, rear fender and footrests are also Thunderbike in-house creations.
The paintwork gives the RS-O its final personality. The design idea was created by Andreas Bergerforth and airbrush artist Ingo Kruse. The color combination of matte black and orange with racing checkered graphics highlights the drag racing style of the bike. The finish looks clean, fast and very purposeful.
In summary, the Thunderbike RS-O customized Dragster RS frame motorcycle is a true showcase of European custom building. It combines a powerful Screamin’ Eagle Twin-Cam engine, radical dragster styling and a large number of in-house engineered components. For riders and fans who love custom Harley-Davidson motorcycles and full frame builds, the Thunderbike RS-O is an excellent example of what high-quality custom craftsmanship can achieve.
