There’s something special about Shiro Nakajima’s work, and it’s painted all over the elegant lines of this custom KTM 690 Duke. Nakajima-san’s creations show a clear affinity to vintage race bikes but look like they’d be more at home on twisty B-roads. They are brutally mechanical yet graceful; retro and modern at the same time.
Shiro’s signature style is a byproduct of his considerable experience. He trained as an engineer, before rising to prominence as the boss of the legendary Japanese restomod house, Ritmo Sereno. He operates as 46Works now, working on furniture, motorcycles, and cars from his beautiful wooden home at the foot of the Yatsugatake Mountains.

Most of the Shiro’s custom builds are big twins, but he has a soft spot for thumpers. ?In the late 1990s, the first motorcycle I acquired was a Yamaha SR400,? he explains. ?It was the heyday of race replicas?but here I was, riding around on that SR400, fully banked on the mountain passes.? ?It was popular in Japan at the time for some enthusiasts to race single-cylinder bikes. The majority raced tuned Yamaha SR and SRXes, and the Suzuki Goose also participated in later years. So a big single is not a mere object of nostalgia to me, but a sportbike.?

Thanks to those memories, Shiro’s always had an itch to create his version of a single-cylinder racer. When the time came to bring his dream to life, he settled on a 2017-model KTM 690 Duke as the starting point. With ...