c.1960s BSA C15 Otter

Manufactured by BSA from September, 1958, until 1967, the C15 was BSA's first four-stroke unit-construction bike. For most of that period, after the introduction of 'learner laws' in 1961, a 250cc was the largest capacity solo machine that a learner could ride unaccompanied when displaying L-plates in Britain. A road-going sports derivative was added in 1961 and off-road versions, for trials and scrambles, were also available in the range. The Otter frame traces its roots to Harry Foster, a West Country motorcycle enthusiast and builder in the UK during the 1960s. Foster crafted early Otter prototypes by modifying BSA frames (often from B40 or C15 models) for better trials performance—think improved ground clearance, lighter weight, and enhanced handling for observed trials events. These were "garage-built" specials, not mass-produced, however, It's often described as a "hidden gem" in trials circles, sometimes overlooked because it's not a "pure" BSA but a bespoke evolution.

This example, one of just a handful produced, has been subject to a light recommissioning in the current ownership and is reportedly running and riding. An unusual hand-built machine that could be ideal for Pre 1965 trials.