Eligibility: Back to Front

We take a look back at the innovations taking place through the 1970s to develop the concept of the reverse cylinder two-stroke race bike. The idea had been around since the 1920s with manufacturers such as Opel, DKW, Honda and Suzuki all creating machines with the exhaust exiting the rear of the cylinder. It was to take another decade before Yamaha produced a reverse cylinder GP machine with the TZ250U in 1988.

Take a look back in time

Click through the following timeline to find out more about each innovation – these machines were all one-off prototypes with bespoke frames, experimental exhaust systems and creative engineering. To race a prototype at GP Originals you need to own the original article (a number of these bikes still exist so you never know!)

Reverse cylinder story from France 1975 onwards
French collaboration from Choukroun to Bolle from ’75
British race tuner Chris Mehew begins designing his reverse cylinder machines
Chris Mehew begins thinking backwards from 77-78
Dudley Cramond and Tommy Crawford achieve success with their reverse cylinder two-strokes
Crawford and Cramond’s spine-framed creations
Katayama test an early Yamaha reverse cylinder machine
Katayama’s crossed-up and back-to-front prototype
GP Originals divider graphic