Grinnall (United Kingdom) - AllCarIndex

Grinnall Specialist Cars was a British specialist sports car and motorcycle trike manufacturer founded by Mark Grinnall in the early 1990s. The company initially built around 350 modified Triumph TR8s before introducing its own reverse-trike model, the Scorpion III, in 1992. Designed by Steve Harper, the Scorpion III featured a tubular space-frame chassis, GRP bodywork, and a BMW K-series motorcycle engine mounted amidships, offering a formidable power-to-weight ratio and brisk acceleration.

In 1998, Grinnall developed the Scorpion IV, a four-wheeled variant that retained the Scorpion’s design ethos but used Audi-based automotive engines. The Scorpion IV delivered significantly higher performance, with simulated figures citing 0–60 mph in approximately 3.7 seconds. Over time, Grinnall expanded into motorcycle-based trikes, converting models like the BMW R1200C and Triumph Rocket 3, and later established a manufacturing facility in Stourport-on-Severn.