Words & Images Chris Nelson
Shinya Kimura of Chabott Engineering in Azusa, California, has a soft spot for the Yamaha SR400 and SR500. Kimura first fell in love at 16 years old, when the unpretentious single-cylinder motorcycles debuted in 1978. “This is my gratitude for Yamaha SR500,” Shinya says. “I’ve always loved this motorcycle, and I’ve always owned a Yamaha SR or XT500 ... always, even when I had a Harley-Davidson shop.”
While Shinya madly customized Harley-Davidsons in his former shop, Zero Engineering in Okazaki, Japan, he still rode home on a Yamaha SR. He appreciates the SRs simplicity and thinks it’s most endearing when left stock, which is why for decades he wouldn’t dare modify his SRs. He built his first-ever custom SR400 last year — a tiny, tidy, low-slung café racer with a baby blue fuel tank — then last November turned his attention to the SR500.
“Crystal Trophy” mates the engine from a 1978 SR500 with componentry from a 2018 SR400. Shinya says, “Since it was SR’s 40th anniversary, we called this project ‘1978/2018 SR500/SR400,” which is why he put a cute “40” badge on the rear haunch of the SR500. Designing the bike, Kimura challenged himself to retain Yamaha’s traditional body lines and the SR’s straightforwardness, but wholly change the character of his creation. “Overall design is the most important thing for me when I’m making a motorcycle. From front tire to back tire, it has to flow,” Shinya says.
He handmade the SR’s bodywork, rear sets, and swingarm, sourced from a Kawasaki KX250. The front cowl blends nicely with the deeply dished tank, and a strong shoulder line carries through the seat and into the rear cowl, which houses the tip of a straight-through exhaust; the cowl is louvered at the bottom to improve heat dispersal. Shinya rebuilt the single-cylinder engine with new piston and camshafts, and added a Keihin CR carburetor and an oil cooler from a Honda XR250.
Shinya carefully considered the SR’s performance-minded suspension, using rear shocks from Works Performance and front forks from Dunstall. The SR’s rear brake comes from a Yamaha XS650, and its four-puck, front drum brake is from a 1969 Yamaha TD3 race bike; Shinya picked it up at a swap meet awhile bike. The SR sits on 16-inch spoked wheels. “No one puts 16-inch wheels on an SR ... I love that,” Shinya laughs. “I wanted to have the shortest possible spokes. I love this setup.”
Shinya says, “As I built this bike, I always imagined taking up canyon roads. That’s why the bike is called ‘Crystal Trophy,” named after Crystal Lake, which lives 45 minutes from Shinya’s shop toward the end of San Gabriel Canyon Road. After the SR500 makes its debut this weekend at L.A.’s Outlier’s Guild “OG” Moto Show, Shinya brings the bike back to his shop and start riding it through nearby Azusa Canyon with his wife, Ayu.