Cycle News is a weekly magazine that covers all aspects of motorcycling including Supercross, Motocross and MotoGP as well as new motorcycles
Issue link: https://magazine.cyclenews.com/i/128366
~S~p-o-rt-ra-c'k-:-L-=-B---:7:-:2=-------------------:----completely crazy idea, but what the hell. Knowing that the frame on the Harley would never be able to deal with off-road suspension, they soon realized that they would have to make a new one from scratch. But they also had the deadline of the Enduro du Touquet approaching in a hurry. The project got under way with a call to Harley-Davidson France, asking if the distributor would like to get involved in the project. Instead of laughing at the two dreamers, Harley shipped them a brandnew 1200cc Evo motor. The heart was there, so now Dr. Frankenstein and friends could start working on the rest of the bike. The purpose of the chassis was to be the link between the rider and the motor, so the stock Harley rolling chassis couldn't possibly remain in any shape or form. The solution was to butcher a Yamaha YZ2S0 for parts and then create the chassis itself from scratch. The organs that they used for the transplant were the front and rear wheels, the brake system, fork and triple clamps, the rear sprocket (belt drive on the sand, are you crazy?), the swingarm and the rear shock. The chassis was finally drawn on paper, but there were already obvious problems. The extremely long engine, compared to the yz's single-cylinder motocross motor, was the biggest problem facing them when it came to creating the compact geometry they were looking for. The solution they found was to machine an aluminum beam onto which the swingarm pivot, footrests and shock mountings would attach. On top of the beam is the spine of the chassis (an idea lifted from the Benelli Tornado superbike), a square tube leading to the front end. Everything else bolted to that. This solution provided a 1600mm wheelbase, which was only IOOmm longer than a conventional motocross bike. For the creation of the beam, Boutry took advantage of his own company's facilities, which produce aluminum molds for the automobile industry. There the two Frenchmen created the beam from an 88pound Fortal aluminum ingot on CNC equipment. Once scheduled, it took the CNC machine almost the entire weekend, over 40 hours, to machine the beam. The leftover scraps were then used to machine other custom items, such as the footrests, engine mounts, and the swingarm pivot insert. Having such industrial devices at their fingertips helped fuel the dream. The bike was finished just in time for the race, but the things didn't go exactly as planned. During the race, the rider fell, and a 38S-pound enduro bike doesn't exactly crash gracefully - especially after another rider rides over the top of it and destroys the seat and tail section. It was difficult enough to ride with the seat, but a nightmare without it. After a DNF, the bike was stored in the garage at the dealership and forgotten, making the cleaning lady grumble because of the sand and oil on the garage floor. In the fall of 2004, Dubreucq decided to put it back together again, but this time for the tarmac. The motor had already been stuffed with various parts from the H-D Screamin' Eagle and Buell catalogs. The crank is a Buell item, as are the exhaust headers, in addition to a Screamin' Eagle twin-spark electronic ignition and camshaft, and a then a Keihin 42mm carburetor was added. Dubreucq then added a Vance and Hines SS2R exhaust canister, which was tucked up and out of the way under the seat, while a Green filter was bolted onto a Forcewinder intake with a Twister RAM airbox. A new 3-liter aluminum oil tank was tucked in below the seat, the only place there was room for it - a hot place indeed, but the oil is cooled at the front of the bike thanks to an oil cooler hiding behind the number plate. The 8-liter fuel tank and the seat give the bike the HarleyDavidson XR7S0 dirt-tracker look they were aiming for. They updated the old yz rims with black WRP rims, with hubs of the same brand. Up front, a 320mm Blade disc brake is squeezed by a four-piston Nissin caliper from the poor, butchered YZ2S0. To say that the brake is overtaxed would be an understatement, but a new six-piston caliper is on the way to help get the nearly 400-pound bike stopped. Now that the project is complete, Dubreucq and Boutry are thinking about selling a chassis kit for other Harley enthusiasts to build a similar bike of their own but don't expect it to be cheap. Rumor has it that even Erik Buell has inquired about the bike himself. Can a Buell factory-backed supermoto team be far away? If one turns up, then just remember who thought of it first! eN The aluminum beam that is the key to the chassis is visible from the side and from the top in the two photos here. It is the unit that the footpegs and shock bolt to (just in front of the exhaust canister in the photo on the right). WRP hubs and rims with Blade brake rotors make up the front wheel set, but the overtaxed YZ250 calipers will soon be replaced by six-piston units for more stopping power. Remember, the bike's heart and saul are from a Harley-Davidson, sa the fuel tank and rear-seat section were designed to resemble a XR750 dirt tracker. 28 FEBRUARY 23,2005 • CYCLE NIW.