American Motorcycle Dealer AMD 169 August 2013 | Page 55

TRIBUTE TO HAGAKURE Written by Duncan Moore - [email protected], Photos by Onno Wieringa - [email protected] In a first for the AMD World Championship of Custom Bike Building, Laurent Dutruel took a Bonneville race bike and entered it in a custom show and in doing so took the runner-up trophy at the 2013 Championship Laurent Dutruel has found a simple way of explaining why he built Tribute to Hagakure O VER the course of the AMD World Championship of Custom Bike Building’s history there has been a number of builders who have entered bikes in the show and then taken them to race at Bonneville on the salt. However, 2013 was the first time a bike that had previously raced on the salt has been entered in the show. The builder who achieved this feat was Frenchman Laurent Dutruel, of Zen Motorcycles, with his build Tribute to Hagakure. As the name of the bike suggests the design was inspired by broad tracker created in 1995 by Japanese builder Masayuki A The front pulley on the primary drive uses a lawn mower-style pull cord to start the motor www.AMDchampionship.com Morimoto, which was called Hagakure. Laurent’s intention from the very start of the build was to take it to Bonneville and set a speed record. The record he wanted to set was for a rigid bike. The only problem was that there wasn’t, nor is there yet, a class for rigid bikes, so he simply went out and rode as fast as possible, with the ultimate aim of going over 200kph. And, as the graphics on the bike’s back wheel show, he reached 208kph on the Bonneville salt in 2011. t the very beginning of the planning stage of the build of Tribute to Hagakure, Laurent had very distinct ideas about how the bike should be set-up, not least of which was no suspension. This, of course, meant that a frame had to be fabricated from scratch. However, given that Laurent also makes bespoke metal furniture it was a relatively simple task for him to translate his thoughts into reality. To match the frame and achieve the goal of having a fully rigid bike Laurent then went on to craft his own forks for the front of the bike too. There are a few concessions to modernity on the frame of Tribute to Hagakure. For example the oil is in the frame and to meet the regulation of land speed racing a steering damper runs from the frame to the forks. Everything else surplus to the need for speed has been left off and that includes any kind of springs under the seat, which mounts directly to a spur off the backbone of the frame. The removal of all unnecessary parts is not D restricted to the frame either. While Laurent is using a Buell XB9 motor it has had the gearbox removed. Nor has the gearbox been replaced with one from another manufacturer. There simply isn’t a gearbox. All that remains of the drivetrain is the clutch, so that the bike can be stopped with the engine still running. Of course, the removal of the gearbox has meant that a regular electric starter can not be used, nor for that matter can a kick start be employed. Laurent’s solution to starting the bike is to employ a lawn mower style string pull on the end transmission’s front pulley. ue to the stripped down nature of the build, not to mention the lack of battery, the stock fuel injection arrangement has been junked, and in its place Laurent has fitted a Mikuni HSR 48 carb. To allow for fine tuning of the gearing for speed on the salt a chain is used for the final drive. In order to get the bike rolling Laurent turned to H-D for a set of wheels and used a seven-spoke 2.75 x 19in wheel at the front, and a solid 3.5 x 19in wheel AMERICAN MOTORCYCLE DEALER - AUGUST 2013 55