Derbi 125 V twin

 The Derbi 125 was basically two horizontal rotary disc singles stacked vertically. At its introduction in 1967 the engine produced 30 hp, growing to 36 by the time it was discontinued two years later. It won no races and though interesting, was not considered a success.

Mick Walker, Spanish Postwar Road and Racing Motorcycles, Osprey Publishing 1986