Zenith was built in England between 1904-1950. The problem with these early belted engines is that they have only 1 gear. In a hilly environment, this is a problem. In 1907, Freddie Barnes at Zenith designs an ingenious system to solve this without using a real gearbox. On the tank is a large carousel that allows the front pulley to open and close. Fully open, the belt runs on a roller bearing and the engine is in neutral. Turned closed, the belt runs higher in the pulley giving you a different gear ratio (Gradua = Gradual gearing). But this makes the belt either too long or too short, causing it to slip. Zenith had solved this problem by also shifting the entire swingarm in the 2 horizontal frame tubes to the front or back so that the distance changes and the tension on the drive belt is always right. This system was so good that Zenith started winning all races and hill climbs. This got so bad that Zenith was excluded from all races to give the other riders a chance at the prize money as well. This in turn was used as an advertising stunt by Zenith. Their Logo was crossed out by a red line with "BARRED" in it. Which referred to the too good system they had and were therefore barred from racing.

The Zenith offered here is the large version with a 770cc JAP V-twin engine.