Grinnall Specialist Cars

Grinnall Specialist Cars is a British low-volume vehicle manufacturer and specialist engineering company founded by Mark Grinnall. The business developed from automotive modification work, particularly involving Triumph sports cars, before becoming associated with three-wheeled vehicles and motorcycle trikes. Its activities occupy the niche between bespoke vehicle construction, performance conversion and specialist motorcycle engineering rather than conventional mass-market automobile production. The company's early work included modifications to the Triumph TR7. It subsequently built a limited run of approximately 350 Grinnall TR8 vehicles based on the Triumph TR8 concept and platform. These projects established the company's reputation for re-engineering existing performance vehicles and producing distinctive, low-volume derivatives rather than designing a broad range of independently developed cars. In 1991, Grinnall moved formally into the manufacture of three-wheeled cars and motorcycles, generally described as trikes. Its first major trike product was the Scorpion III, introduced in 1992. The Scorpion III was an open two-seat, three-wheeled sports vehicle powered by a BMW K1100 motorcycle engine. Its lightweight configuration and motorcycle-derived powertrain gave it sports-car performance, with published descriptions stating that it could exceed 130 mph. The model attracted attention from enthusiasts and received public support from Roger Cook, associated with The Cook Report television programme. By 1999, Grinnall had shifted its principal emphasis from three-wheeled sports cars toward motorcycle trikes. The company initially converted BMW R1200C motorcycles, with the resulting trike introduced in 2000. It later developed conversions based on BMW motorcycles including the R1200CL, Montauk and R1150R. From 2005, it also offered a trike based on the Triumph Rocket 3, extending the company's work to a large-displacement British motorcycle platform. Grinnall's business has therefore combined manufacture and conversion. Some products were purpose-developed three-wheeled vehicles, while others were transformations of established BMW or Triumph motorcycles into trikes with revised rear structures, additional wheels and associated chassis and bodywork changes. The company also manufactured trike models for Indian Motorcycles and owned the Birmingham dealership for the Indian brand, according to reference material describing its operations. In 2015, Grinnall moved to a new facility in Stourport-on-Severn. The move is an important location milestone, although publicly available reference material does not provide detailed information about production volumes, ownership structure, current leadership or financial performance. Grinnall remains best understood as a specialist British manufacturer serving enthusiasts who value unusual layouts, motorcycle-derived performance, limited production and individual conversion work.

Grinnall Specialist Cars was established by Mark Grinnall in the United Kingdom as a specialist vehicle engineering and manufacturing business. Its earliest identity was closely tied to modification work on Triumph sports cars, including the Triumph TR7. The company later produced a limited run of around 350 vehicles known as the Grinnall TR8, based on the Triumph TR8. These activities placed Grinnall within the British tradition of low-volume performance-car specialists that adapt existing platforms for improved performance, distinctive styling or more individualised ownership. A major change came in 1991, when Grinnall formally entered the manufacture of three-wheeled cars and motorcycles. The company's first prominent model in this field was the Scorpion III, launched in 1992. It was an open two-seat sports vehicle with three wheels and a BMW K1100 motorcycle engine. The use of a motorcycle powertrain was consistent with the company's broader approach: combining comparatively light, unusual vehicle structures with readily identifiable performance-oriented components. The Scorpion III was described as capable of speeds above 130 mph and became the company's best-known car-oriented product. Roger Cook, associated with The Cook Report, was noted as a prominent owner and supporter. During the late 1990s, Grinnall's business direction changed. By 1999, the company had moved away from making three-wheeled sports cars as its central activity and concentrated on motorcycle trikes. The first major motorcycle conversion was based on the BMW R1200C and was launched in 2000. Grinnall subsequently worked with other BMW platforms, including the R1200CL, Montauk and R1150R. These products were not conventional motorcycles in their original form; they were specialist conversions that reworked the rear of the motorcycle into a three-wheeled configuration and added the engineering, bodywork and structural components needed for the new layout. From 2005, Grinnall expanded its motorcycle-trike range to include a Triumph Rocket 3-based model. This gave the company a British high-capacity motorcycle platform alongside its BMW-based products. Grinnall also manufactured trike models for Indian Motorcycles and operated the Birmingham Indian Motorcycles dealership, broadening its role from independent converter to a specialist participant in the retail and distribution ecosystem surrounding premium motorcycles. The company relocated to a new facility in Stourport-on-Severn in 2015. Public reference material does not establish a detailed corporate ownership history, production scale, financial record or complete account of current management. Its documented development nevertheless shows a consistent specialization: low-volume, enthusiast-oriented vehicles built around unusual three-wheeled layouts, motorcycle-derived powertrains and customized engineering. Grinnall's history is consequently less a story of mass production than of successive niche products and platform conversions tailored to customers seeking distinctive performance vehicles.

• 2015

  Relocation to Stourport-on-Severn

  [1]Grinnall Specialist Carsen.wikipedia.org

  Grinnall moved to a new facility in Stourport-on-Severn.

• 2005

  Triumph Rocket 3 trike launched

  [1]Grinnall Specialist Carsen.wikipedia.org

  Grinnall introduced a trike conversion based on the Triumph Rocket 3.

• 2000

  BMW R1200C trike introduced

  [1]Grinnall Specialist Carsen.wikipedia.org

  A Grinnall motorcycle trike based on the BMW R1200C entered the company's product range.

• 1999

  Strategic shift to motorcycle trikes

  [1]Grinnall Specialist Carsen.wikipedia.org

  Grinnall changed its main emphasis from three-wheeled sports cars to motorcycle-based trikes.

• 1992

  Scorpion III launched

  [1]Grinnall Specialist Carsen.wikipedia.org

  The company introduced the open two-seat Scorpion III, a three-wheeled sports car powered by a BMW K1100 motorcycle engine.

• 1991

  Formal move into three-wheeled vehicle manufacturing

  [1]Grinnall Specialist Carsen.wikipedia.org

  Grinnall formally entered the manufacture of three-wheeled cars and motorcycles, commonly described as trikes.

A niche British specialist focused on high-performance, low-volume and highly individualised three-wheeled vehicles, motorcycle trikes and performance conversions.

• Modified sports car

  Grinnall TR8

  A limited-run sports car developed from the Triumph TR8. Grinnall's work on the model followed its earlier modification activities involving the Triumph TR7 and reflected the company's early role as a British performance-car specialist. Reference material identifies an output of approximately 350 vehicles.

• Three-wheeled sports car · 1992

  Scorpion III

  An open two-seat three-wheeled sports car launched in 1992. It used a BMW K1100 motorcycle engine and was reported as capable of exceeding 130 mph. The Scorpion III became Grinnall's best-known car-oriented product and helped establish the company in the specialist three-wheeler market.

• Motorcycle trike conversion · 2000

  BMW R1200C-based trike

  A three-wheeled conversion based on BMW's R1200C motorcycle. Introduced around 2000, it represented Grinnall's shift toward motorcycle trikes and used the company's specialist engineering approach to adapt a production motorcycle into a wider, three-wheeled vehicle.

• Motorcycle trike conversion

  BMW-based Grinnall trikes

  Grinnall developed additional trike conversions using BMW motorcycles including the R1200CL, Montauk and R1150R. These products extended the company's BMW-based range and served riders seeking a specialist three-wheeled configuration rather than a standard two-wheeled motorcycle.

• Motorcycle trike conversion · 2005

  Triumph Rocket 3-based trike

  A high-capacity motorcycle trike based on the Triumph Rocket 3. Introduced from 2005, it brought Grinnall's conversion work to a large-displacement British motorcycle platform and complemented the company's BMW-derived products.

• Motorcycle trike conversion

  Indian Motorcycle trike models

  Grinnall manufactured trike models associated with Indian Motorcycles. The available reference material does not specify individual model names, technical specifications or production dates.

• 2015

  Relocate to a new Stourport-on-Severn facilityOther

  Background

  The company required a new operating location for its specialist vehicle activities.

  Action taken

  Grinnall moved to a new facility in Stourport-on-Severn.

  Aftermath

  The relocation established Stourport-on-Severn as the company's documented base.

  Source

• 1999

  Prioritise motorcycle trikes over sports carsStrategy

  Background

  After developing the Scorpion III and other specialist sports-car projects, Grinnall reassessed its product focus.

  Action taken

  The company shifted its main manufacturing emphasis toward motorcycle-based trikes.

  Aftermath

  The strategy led to BMW and later Triumph motorcycle conversions becoming central to Grinnall's documented product activity.

  Source

1. 1Grinnall Specialist Carsen.wikipedia.org
2. 2Grinnall Specialist Cars official websitegrinnallcars.com