Based in Belgium, Fred 'Krugger' Bertrand has built the Yamaha SR400 that you see here, as the latest addition to Yamaha's Yard Built custom bike program. Inspired by Yamaha's MotoGP heritage, the SR400 has been built in collaboration with Fred's friend and fellow Belgian, Bernard Ansiau, who happens to be a mechanic for... Valentino Rossi! And if that weren't enough, Ansiau has even worked on the bikes raced by former greats like Wayne Rainey, Kenny Roberts, Randy Mamola and Norick Abe.
Together, Fred and Bernard have built this SR400 in tribute to Yamaha's 1970s TZ racebikes. "I think it's impossible to have a custom machine that lives and breathes our racing history better than this," says Cristian Barelli, Yamaha Motor Europe's Marketing Coordinator. "It's such a beautiful bike and the longer and closer you look at it, the more detail you find to enjoy. You wouldn't normally associate the SR400 with MotoGP racing, but this build is as genuine and authentic as it's possible to get, a real Yard Built special," he adds.
In order to extract some performance from the air-cooled single-cylinder SR400 engine, Fred and Bernard have given it an Aisin 300 supercharger, with a custom-built plenum chamber, a one-off stainless steel exhaust system and an S&S 48mm carburettor in place of the original fuel-injection system. No power figures have been quoted, but the stock engine makes 23bhp and 27Nm of torque, so the supercharged Krugger SR400 probably packs at least 30-35bhp and 35-40Nm of torque. Not very MotoGP, but what the heck, every little bit helps. Probably.
Other interesting bits on the bike include polished, lowered and balanced front forks, Fox shocks at the back, a set of Dunlop K81 tyre (inspired by the first tyre to lap the Isle of Man TT course at over 160kph!), a Motogadget speedo, custom tailpiece, a small cowl at the front that sits above a modified top triple clamp, and custom handlebars. The brakes and clutch have been upgraded by Beringer and are now more likely to be up to the task of handling the supercharged engine's increased power and torque output.
The Krugger SR400 retains the standard Yamaha SR400 fuel tank, with blue and white Yamaha Speedblock colours. The bike looks good, but we have to admit that it leaves us wondering - what would Krugger have done had they used a Yamaha MT-10 for this project, instead of an SR400? Supercharged, 200bhp retro-styled MT-10, anyone...?