GYS were motorcycles produced from 1949 to 1955, in Bournemouth and distributed by the Cairns Cycle firm.
1949-1950 The 50cc unit was an all-alloy cyclemotor attachment that fitted above the front wheel, which it drove by friction roller. It had an upright cylinder that was cast in one with the crankcase. The silencer bolted directly to the cylinder and both it and the petroil tank were aluminium castings. The whole unit was carried in a frame that could be raised or lowered for contact with the tyre.
1951 A kit was offered by Cobli of London, to mount the engine under the saddle in order to drive the rear wheel. That year the GYS name was changed to Motomite.
1952 The name changed yet again, this time to Mocyc.
1955 Still known as the Mocyc, the make came to an end.
Mocyc was the name used by the all-alloy GYS cyclemotor from 1952 to 1955.