The Minstrel Cycle Company became the Minstrel & Rea Cycle Company in 1905 and started making motorcycles in 1909. The company name changed again to the Calthorpe Motor Cycle Company, and production continued until 1938.
In the late 1920s, the company launched a new range under the sub-brand of Ivory Calthorpe. Using a self-produced single-cylinder sloper-design engine, the engine was similar in proportions and output to contemporary BSA units. The ohv twin-port 348cc launch unit was fitted into a full-cradle duplex frame, and used a 3-speed Burman gearbox, with a tank mounted change. The engine breathed through an AMAL carb, and used a BTH magneto mounted to the rear of the cylinder. By 1935 there was a 498cc option, but top speeds were similar at around 70 miles per hour (110 km/h). The design was sit-in as opposed to traditional bicycle sit-on design, later described by one tester as a "sack-of-potatoes slump!"With a marketing unit by no sales team, the motorcycles were exclusively sold by London-based dealer Pride & Clark in Stockwell Road, Brixton.P&C stated that the units should be sold at £52 and £54 respectively - a relatively high pricing for the time, but one which left a slim margin for Calthorpe MCC.
When the receiver sold the works in 1939, Bruce Douglas, the nephew of the founder of Douglas, bought the Calthorpe equipment and moved it to Bristol. He built new models powered by 347cc and 497cc Matchless engines, but only a few were built before production was stopped by the outbreak of World War II. Production did not recommence after the end of the war, and the equipment was sold to DMW.