He is the creator and former owner of Ritmo Sereno, a company renowned for its impressive restomods that have gained international recognition. Despite moving on to his second venture, Shiro continues to produce remarkable machines, but now focuses on fully customized motorcycles. The particular bike we are about to examine is the newest addition to his project collection, which was unveiled on 46Works’ Instagram page in January of this year.
Originally a Triumph Bonneville T140 from 1976, our protagonist transformed it into something much more thrilling. Master Nakajima drew inspiration from vintage desert sleds for the visual design, ultimately choosing to base his creation on one of Steve McQueen’s most famous motorcycles. We are, of course, referring to the renowned #955 Triumph TR6 desert racer, which is considered one of the most iconic bikes of its kind.
This custom build was commissioned by a client who desired a combination of desert sled aesthetics and track-friendly performance. The client plans to participate in a Japanese racing series called Legend of Classic, and this impressive T140 is their chosen weapon for the competition. Shiro didn’t just create a visually stunning bike with McQueen’s charm, but a genuine race machine built to excel on the track.
The project didn’t start with a complete motorcycle, as the client only provided the Bonneville’s engine, frame, and swingarm. To kickstart the process, Nakajima-san enlisted the expertise of Gladstone for a comprehensive overhaul of the powertrain. The parallel-twin engine was sent to Gladstone’s headquarters in Shizuoka, where it received upgrades such as new cams, high-compression pistons, and Keihin CR carburetors with velocity stacks.
Gladstone also made revisions to the cylinder head, and power is now transmitted to the rear wheel through a five-speed gearbox and a belt final drive. As for the custom exhaust system, Shiro meticulously crafted a titanium unit from scratch. The exhaust features a drilled heat shield to prevent excessive heat near the rider’s leg.
Moving on to the chassis, 46Works utilized billet aluminum triple clamps and a specially made steering stem to install a fresh pair of forks at the front. These forks were sourced from a classic Yamaha but were fitted with modern internals before being installed. Premium aftermarket shocks were chosen for the rear suspension. The bike is equipped with 18-inch Excel wheels, repurposed from Yamaha, and fitted with Avon tires – a Roadrider tire at the front and an AM18 Super Venom at the rear.
To ensure optimal stopping power, the T140 is equipped with high-performance braking components. Twin AP Racing brake calipers are installed at the front, along with a single Brembo module at the rear, and drilled Sunstar rotors on both ends.
Image: 46Works
Brembo provided a pair of top-quality master cylinders, and all the connections were made using new hoses. On the flip side, the Bonnie’s rearsets and their associated linkages are custom-made parts produced in-house. The bodywork department took inspiration from Steve McQueen’s TR6, with a replica Triumph gas tank proudly taking center stage.
This tank sits just in front of a handcrafted solo seat, which was created on an aluminum base and upholstered by Razzle Dazzle. Custom number boards are positioned on either side of the saddle, along with a sleek high-mounted fender at the rear. Since the Triumph was intended to be a full-fledged racer, there was no need for a license plate bracket or any lighting components.
At twelve o’clock, a simple mudguard and a flat number plate with #955 TR6 vibes were added, but the cockpit underwent significant changes as well. The instrument cluster now consists of a standalone lap timer, a digital temperature display from Daytona, and an analog tachometer supplied by Stack. A low-profile handlebar with minimalist controls completes the equipment in that area.
For the final touches, the creative mind at 46Works installed a Setrab oil cooler with Kinokuni fittings, as well as a custom-made oil catch can. The T140 desert sled was then entrusted to Drops Design Works for the paint job, which involved applying a stealthy gloss-black finish to components such as the fuel tank, rims, and frame. Other aluminum bodywork parts were left unpainted to create contrast, as were the engine covers and titanium exhaust pipes.