The Robert Lusk Motorcycle Collection, 1922 Downer-Groves 249cc Tandem

This unique motorcycle is the creation of Cecil Downer-Groves, a prolific inventor with numerous patents to his name. Born in Jamaica to English parents on 12th February 1880, he moved to the UK at 17 to train as a pattern maker's apprentice, acquiring extensive skills in prototype engineering. He lived in Croydon, Surrey, for the rest of his life. CD-G's patented inventions include a collar stud safety device, handlebar-mounted twist-grip gearchange, two-stroke engine valve, spark plug heater, and a reversible propeller for outboard motors. His creations also encompassed two-stroke engines, a model aircraft, gramophones, a guitar, cameras, an automatic cigarette vending machine, and various sidecars - including the boat-style 'chair' for a Matchless combination also offered as part of The Robert Lusk Collection (Lot XXX). Beyond engineering, he made furniture, was a skilled woodcarver, and developed his own films.
Employed at a local engineering firm on modest wages, and with a family to support, CD-G could not afford standard tools and crafted his own, including a treadle-powered lathe. Needing a means to transport batteries for a small charging service he offered locally, he purchased a bicycle, for which he made a sidecar and engine. Wooden patterns were used to cast and meticulously machine the major components of his two-stroke engine before assembly. While it is not clear whether this tandem was originally purchased for that purpose, at least one other CD-G-powered bicycle (a solo) was known to exist, advertised in the motorcycling press by MD Motorcycles of Wellington, Somerset (press cutting on file).
Accompanying documentation states that the tandem - believed to pre-date World War I - was purchased in 1922 and motorised for easier travel. The engine, made entirely from scratch, was installed in a suitably strengthened frame. According to CD-G's granddaughter, "the finished engine produced the desired effect and the tandem and passengers enjoyed many years and miles of effortless travel."
Cecil Downer-Groves died in 1970, aged 91, and the tandem subsequently passed to the late Terry Martin, who enjoyed riding it in historic events, including the VMCC Festival of 1,000 Bikes, International Rally, and Banbury Run during the early-to-mid 1980s. Purchased by Robert Lusk at Bonhams' October 2011 Stafford Sale, when we were selling it on behalf of Terry's partner, it has remained in Robert's collection ever since.
Presented in original "oily rag" condition, this remarkable machine is a testament to the skill and inventiveness of its creator. It is offered with a substantial history file, including correspondence, press cuttings, photographs of the machine as found by Terry Martin, expired MoTs (most recent 1987), insurance documents, and V5C registration. One of the original casting patterns for a crankcase half is included with the sale. At the time of cataloguing it was not possible to locate the engine number.

Prospective buyers should please note that whilst Robert actively started and maintained his collection, all machines are offered as requiring recommissioning to a greater or lesser extent.
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