Dark and moody: Twinline’s Kawasaki S1 cafe racer

Twinline's Kawasaki S1 cafe racer
The Kawasaki S1 is rarely found in the US. Which is a pity, because this air-cooled two-stroke triple is reportedly a fun ride. Sometimes known as the ‘Mach 1’, it lived up to its name—road testers managed to wring almost 100 mph out of it in the early 70s.

This dark and subtle café racer comes from Twinline Motorcycles of Seattle, who impressed us a couple of years ago with their Project Goldhead Yamaha RD350. According to builder Ian Halcott, ‘We built this bike in our spare time over the winter. I like it when I can just build … No requirements, no expectations.’

Twinline's Kawasaki S1 cafe racer
There was not an auspicious start to this project, though. ‘A friend bought the bike at top dollar, and three miles down the road the life went out of the motor. When he asked the seller what was up, he shrugged his shoulders and said, “That’s vintage bikes.”’

Twinline's Kawasaki S1 cafe racer
So Twinline overhauled the engine and stripped the Kawasaki S1 back to the frame before rebuilding it café style. It’s now got clip-ons, an H1 swingarm and rear wheel (for a wider tire), and longer shocks to create a more aggressive stance. Given that triples are inherently asymmetrical, Halcott also moved the taillight off to one side and did the same with the headlight arrangement.

‘Its personality changes as you walk around the bike,’ he says. It’s a dark and moody personality, and I love it.’

Images by Todd Blubaugh.

Twinline's Kawasaki S1 cafe racer