When the Zenith factory of Hampton Court, England came out with their remarkable “gradua,” or infinitely variable gear in 1912, they were barred from racing, and adopted “Barred” as a slogan. Another earlier claim they touted, was “Built of finest quality throughout. We employ no female labor”. Needless to say, they decided to drop that claim after the ladies got the English vote! This Zenith, with its 1000 cc JAP twin, is the owner’s favorite mount for pre-16 runs. The gradua gear has a V-belt drive with a variable front pulley controlled by the crank atop the fuel tank. As the pulley squeezes together increasing the ratio, the rear wheel is moved forward via worm gears to compensate. Gearing varies from 8:1 to about 3:5 to one at the rear wheel. Thus any ratio in between can be chosen, and this makes it very efficient on hills, provided the belt is kept adjusted properly. Belt drive is very smooth, but belt slip is the bane of the belt drive machine, particularly in wet weather. The big JAP puts it to the test!

Impressions from the Saddle
The Zenith is started on its stand, and the location of the kick-starter is such that you stand in front of the machine, and kick towards the rear. As the starter is on the right side, you either straddle the front wheel or kick with your left foot. It takes a good one, as it’s a 1000cc V-twin. Once running, the clutch is released, off the stand, and away, releasing the clutch. No clutch slip with this one, but the belt drive absorbs the shock, and wheelies are avoided. When a taller gear is required, the crank on the top of the tank is turned counter-clockwise. The trick is to turn the handle gradually, keeping the engine running at its most efficient rpm. The Zenith is a powerful long legged device, so cruising at 55mph is a piece of cake, and it will probably do 75 or 80. When you start up hill and the engine slows down, you simply unwind the crank until the engine is spinning happily again. The handling is better than the other early machines, but the rim brake is almost useless. The saving feature is the gradua gear. Cut the throttle, and wind the crank clockwise, using the engine as a brake, and use the foot brake for final stopping. Tailgating is not reccomended!

Listen to the Zenith.

Click and drag the QTVR image below to rotate the Zenith.