Zenith 1914 Gradua 3½ HP 494 cc 1 cyl sv 3504

Zenith 1914 “Gradua” 3 ½ HP 494 cc JAP side valve singe frame # 2957 engine # 14547

Zenith machines were manufactured from 1904 till 1950, in a variety of factories in or around London. From the early days proprietary engines were used, such as Fafnir, Green-Precision, JAP, Bradshaw and Villiers. The latter engines were used in most models from the thirties.

In pre- WW1 days Zenith machines gained many successes; driving force was chief Engineer Freddy Barnes, who was responsible for the famous “Gradua” gear. The mechanics of the Gradua gear were a variable engine pulley worked by a handle, with simultaneous correction of the belt length made by sliding the rear wheel backwards or forwards in the fork slots. Its advantage showed itself most effectively in speed hill climbs. The Zenith rider could change during the journey up while the other competitors had to do with a single choice of gear ratio. Rival riders and manufacturers thought that this was an unfair advantage so many leading clubs barred Gradua gear Zeniths from their hill climbs. Zenith was quick to recognize the publicity value and took the word “barred” as their trademark. In veteran days power sources were invariably JAP, in single and v-twin form, both side and overhead valve. The 1914 range consisted of four models. There were two side valve models, the 3 ½ HP single with bore x stroke of 85.5 x 85 mm and the 6 HP 770 cc twin with bore x stroke of 76 x 85 mm. For sportsmen two expensive OHV models were available, in 498 cc and 996 cc capacities. For an extra charge a hub clutch and hand starter could be ordered, but the brochure stated that starting without clutch was an easy matter. You made sure the controls were in the right position (throttle half to three quarters open, air closed, spark lever nearly fully advanced) then the petrol tap should be opened and the carb flooded. Next step was to engage the gear with about half a turn of the handle and finally you pushed the machine along at a fast walking pace with the exhaust valve lifter raised. With the engine turning freely, the valve could be dropped and the machine should start. All the rider had to do then was to lower the gear to free engine position, take his seat and start from rest.

This “starting from rest” was checked with every machine on the Brooklands track. Each Zenith that left the factory was accompanied by a Brooklands Certificate that said machine had climbed the famous Test Hill (it’s still there!) from a standing start. This Hill finishes with a gradient of 1:4 and averages 1:5.

The interesting Zenith we offer here is an older restoration. She comes with Pioneer Certificate, Bosch magneto and acetylene lighting set. And of course with the very practical centre stand, a very innovative item in pre-WW1 years.