The Grinnall Scorpion III, by Grinnall Specialist Cars, is a reverse trike, with two wheels at the front and one at the rear, which is a better-handling configuration than one wheel at the front. Designed in 1991 by Steve Harper, the Scorpion III features a GRP body tub which is bonded to a space frame chassis underneath, and employs a BMW K-series motorcycle engine as its power plant. The engine, gearbox and final drive from the motorcycle are utilised with a special rear wheel which is fitted with a car tyre, as are the front wheels. It has a very good power-to-weight ratio which endows it with excellent performance. The rear wheel is of a smaller circumference than the bike's wheel so the gearing is optimised for a lower top speed of around 125 mph (201 km/h) with 0-60 mph (97 km/h) tak