c1924 Zenith 346cc Gradua

From the Hitchcock’s Motorcycle Collection


Zenith Motors was established in Finsbury Park London in 1903 by W.G. Bowers and was originally an automobile manufacturer, however this only lasted from one year with one model the ‘Popular’ which had a two-cylinder, 6HP Stevens engine and a belt driven rear axle.

Motorcycle production started in 1912, these bikes used engines from various suppliers including Precision, Villiers and moat famously JAP.  A relatively small manufacturer Zenith had significant success in motorcycle racing and competition in the early 1920‘s, Zeniths held more ‘Gold Stars’ at the Brooklands racing circuit than any other marque, and award that was given for lapping the outer circuit at over 100 mph.

The driving force behind Zenith was Chief Engineer Fred Barnes, who was responsible for the famous ‘Gradua’ gear. Worked by a hand wheel or crank handle, the Gradua mechanism varied the diameter of the engine pulley while simultaneously sliding the rear wheel back and forth in the fork slots, thus maintaining correct belt tension. Its advantages showed most effectively in speed hill climbs, and in pre-WW1 days Zenith riders gained many successes as they could change gear during the ascent while the other competitors had to make do with a single ratio. Rival riders and manufacturers considered this an unfair advantage, so many leading clubs barred Zeniths from their hill climbs. Zenith was quick to recognise the publicity value and took the word ‘Barred’ as their trademark.

In 1931 Zenith declared bankruptcy due to the Great Depression although their principal dealer Writers of Kennington purchased the name and restarted production at a Hampton Court factory in Surrey it was interrupted by WWII. Production did start again from 1947 but only lasted until 1950.

This machine is of the type developed in 1924 and features a single cylinder 346cc side valve JAP engine. It bears the frame number 186, no engine number is visible and it is not road registered. Offered here in ‘barn find’ condition at NO RESERVE.

Sold For £6,187

Auction MCN London Motorcycle Show February 2017
Auction Date N/A
Day of Auction N/A

lot details

Lot Number 274
Registration Number Not Road Registered
Chassis Number 186
Year 1924
Make Zenith
Model 346cc Gradua

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