A remarkably rare 1999 GG Duetto sidecar motorcycle has surfaced for sale in California, offering collectors a chance to acquire one of the most unusual and technically ambitious three-wheeled machines of the 1990s. Built in Switzerland by Grüter + Gut Motorradtechnik GmbH, the GG Duetto blended motorcycle engineering, automotive-inspired comfort, and advanced chassis design into a fully integrated sidecar platform unlike anything else on the road at the time.
Only 30 examples were produced between 1994 and 1999, with sales limited primarily to Europe and Japan. When new, the Duetto carried a price tag of roughly $50,000, placing it firmly in exotic vehicle territory. Adjusted for inflation, that figure would exceed $109,000 today.
The project was the creation of Swiss engineer Walter Grüter, who founded Grüter + Gut Motorradtechnik alongside business partner Daniel Gut in 1983. Initially focused on servicing and selling motorcycles from Moto Guzzi, Ducati, and later BMW, the company gradually expanded into precision aftermarket engineering before Grüter began developing a radically different interpretation of the traditional motorcycle sidecar.
Rather than attaching a sidecar to an existing motorcycle, the GG Duetto was designed from the ground up as a dedicated three-wheeled vehicle. BMW K1100LT mechanical components formed the foundation, including the liquid-cooled 1,092cc inline-four engine equipped with electronic fuel injection and Bosch Motronic engine management. Factory output was rated at 100 horsepower.
The engineering went far beyond the drivetrain. Grüter replaced conventional motorcycle forks with a sophisticated hub-center steering setup featuring a single-sided aluminum swingarm and adjustable WP suspension. The design was intended to better manage the uneven forces created by a permanently attached sidecar. Electronic ABS braking on all three wheels was another standout feature during an era when such technology remained uncommon even on premium motorcycles.
The bodywork was constructed from glass-fiber reinforced plastic and incorporated hidden mounting hardware for a smooth, futuristic appearance. The sidecar passenger compartment featured amenities more commonly associated with luxury automobiles, including carpeting, a BMW bucket seat, an electrically operated entry hood, and an adjustable electric windscreen.
The example currently offered for sale is finished in yellow bodywork and reportedly remains exceptionally well preserved. It rides on custom forged Marchesini wheels fitted with Yokohama tires and includes a polished Staintune exhaust system, heated grips, emergency flashers, and a reverse-equipped four-speed transmission.
The odometer shows 29,000 miles, and the motorcycle is being sold with extensive documentation, including service records, marketing brochures, magazine coverage, and historical ownership materials. The rare Swiss-built machine is now being offered out of Newbury Park, California through Bring a Trailer.
Source
