The Grinnall Specialist Cars Ltd. (often referred as Grinnall Cars) is an automobile and motorcycles maker founded by Mark Grinnall in United Kingdom. This company mainly produced three-wheelers. It is based in Bewdley, Worcestershire
In the beginning, Grinnall Cars started to modify Triumph TR7 cars. By 1990 they produced 350 units of Grinnall TR8 based on Triumph TR8. In 1991 Grinnall started to produce three-wheelers (also known as Trikes). In 1992 they started Scorpion III development. In 1998 started Scorpion IV development.
The company's reputation was first made by its extensively reworked and refined conversions of the Triumph TR7 and TR8. By 1990, some 350 Grinnall TR8s had been constructed. In 2006 The Triumph Register acknowledged the Grinnall TR8 as a marque in its own right, and has compiled extensive history files on the vehicles.
In 1991, in search of a radical but affordable high performance concept, Mark Grinnall turned towards his passion for motorcycling, and his hand to an innovative three-wheeler, which unlike any of its illustrious ancestors would be high-tech, mid-engined and rear wheel driven. This was to be the first in a family of unique, niche-market sporting vehicles. The S-III made its debut in 1992 when it was featured in a CAR magazine article written by a young Colin Goodwin. Interest in the S-III exploded in the mid 90’s, with the breathtaking featherweight being featured in dozens of magazines worldwide.
The next stage of the plan was to create a four wheeled version of the S-III. Development of the Scorpion IV began in June 1998. Research had confirmed the plan was the right one. At motor shows and demonstration days up and down the country at BMW Motorrad dealers - and via our website - a significant number of prospective customers, and some Scorpion III owners too, had been asking us to produce a four-wheeler. They wanted a little more interior room, and even more performance, mainly for the growing track day market. Since that time, several more vehicles destined for this niche have appeared – and some have disappeared. Possibly one of the most successful arrivals is Simon Saunders' skeletal Ariel Atom.
Potential owners were clear that they loved the Scorpion-III’s ultra-modern, minimalist styling. Steve Harper, who designed the S-III was therefore commissioned to style the S-IV to the same ‘form follows function’ design brief, and maintain a clear family relationship between the two.
Findings from the research and development of the highly-acclaimed Scorpion III went into the building of the new Scorpion IV chassis; a space-frame structure which is remarkably rigid, yet respectably light. The front suspension is a development of that which works so well on the Scorpion III. Unequal length double wishbones in oval tubing with inboard coil springs over custom made ‘Ohlins-quality’ dampers built by PHM Engineering in Belgium. Grinnall designed, CNC billet uprights connect the wheels to the suspension using stainless spherical joints which provide adjustable camber and castor. At the rear, long, super-stiff longitudinal links give superb handling and camber control without compromising the vehicle's distinctive styling.
Exhaustive trials of possible power-trains included Rover K-series, Honda VTEC and Fiat 20v turbo - all fine products. Eventually however, we decided to use the incredible Audi/VW 20v turbo unit, which makes 225bhp in standard form and up to 500bhp after the tuning wizards have done their stuff. The slick Getrag 6-speed gearbox compliments this superb motor perfectly.
In 1999 work began on the first of our motorcycle derived trikes – with a single front wheel. The obvious starting point for a great trike was the BMW R1200C – a machine that had the twin advantages of BMW’s tele-lever front suspension and shaft drive. Launched in 2000, this has been a constant seller for us.
To the Grinnall Trike collection has been added the BMW R1200CL, the Montauk, the sportier R1150R, and on 2005 the Triumph Rocket 3 based trike - the R3T. This has been a wonderfully successful machine, and makes probably the best bike/trike on the planet. Continuing with Triumph 2012 will see the launch of the fabulous Triumph Thunderbird 1600 trike. This new machine will herald the beginning of belt/chain driven trikes appearing in the future Grinnall range