Zenith Motorcycles

Zenith Motorcycles

Company type	Private
Industry	Motorcycle and automobile manufacturing
Founded	1903
Founder	W. G. Bowers
Defunct	1950
Fate	Bankruptcy and revival; ceased production
Headquarters	Finsbury Park, London (initial), later East Molesey Mill, Surrey, then Hampton Court, Surrey , United Kingdom
Area served	United Kingdom
Key people	W. G. Bowers (founder), Fred ("Freddie") W. Barnes (chief engineer)
Products	Motorcycles, automobiles
Parent	Writers of Kennington (post-1931 revival)

Zenith Motorcycles was a British manufacturer of motorcycles and automobiles, established in 1903 in Finsbury Park, London by W. G. Bowers. The company’s automobile production was brief, spanning only from 1905 to 1906. Their inaugural motorcycle, the 'BiCar' (1903), drew inspiration from Tooley’s design and incorporated hub-center steering with a low-profile frame powered by a centrally positioned German Fafnir engine.

In 1905, Fred ('Freddie') W. Barnes joined Zenith as chief engineer and developed the "Gradua" variable-ratio belt drive transmission, which adjusted the diameter of the crankshaft pulley while simultaneously repositioning the rear wheel to keep belt tension constant. Operated via a lever mounted on top of the fuel tank, this Gradua system offered multiple drive ratios—a notable innovation compared to the standard fixed-ratio belt drives of that era. Zenith capitalized on this advantage in their branding by appending "Barred" to their logo after Gradua-equipped motorcycles were prohibited in certain competitions. The Gradua mechanism was eventually replaced in 1924 by a traditional gearbox paired with chain drive.

By 1914, Zenith had moved its operations to East Molesey Mill near the Brooklands racing circuit and shifted its production during World War I towards commercial sidecar outfits designed to substitute military horses. Following the war, under Barnes’ guidance, the company emphasized racing and endurance trials. Zenith utilized engines from various suppliers including Precision, Villiers, Bradshaw, Martlett, British Anzani, Fafnir, and JAP.

Although Zenith remained a relatively modest manufacturer, it distinguished itself with significant achievements in speed events throughout the 1910s and 1920s. During this period, under Barnes’ leadership, Zenith earned more Brooklands 'Gold Stars'—awarded for laps exceeding 100 mph—than any other brand. Their racing motorcycles featured sophisticated single-cylinder and V-twin engines such as DOHC JAP singles, twin-cam JAP sidevalve V-twins, Martlett OHV 1000cc V-twins, Blackburne OHV 1000cc V-twins, and JAP KTOR/JTOR OHV 1000cc V-twins. Renowned riders associated with Zenith included Ted Baragwanath, Bert LeVack, Owen Baldwin, H.M. Walters, and Joe Wright.

The company succumbed to bankruptcy in 1931 due to the economic downturn caused by the Great Depression but was revived by 'Writers of Kennington,' one of its principal dealers who resumed production at a factory located in Hampton Court near Hurst Park racecourse in Surrey. Production was again halted during World War II and ultimately ended in 1950. The final models produced between 1947 and 1950 employed JAP 750cc sidevalve V-twin engines and remained largely unchanged from their pre-war predecessors.

Automobile history

From 1905 to 1906, Zenith released the Popular model which was equipped with a two-cylinder Stevens engine delivering 6 horsepower and featured a belt-driven rear axle.

Speed records

Zenith actively built its reputation through participation in competitive events. Freddie Barnes consistently secured victories on Zenith motorcycles between 1909 and 1913. In 1922, rider Bert le Vack made history by completing the first British motorcycle lap at Brooklands exceeding 100 mph on a Zenith machine. By 1925, Zenith had accumulated the highest number of 100 mph laps at Brooklands, with factory rider Joseph S. Wright holding the lap record there until 1935.

The company twice set new motorcycle world speed records. The initial FIM-sanctioned record of 124.55 mph was established in 1928 by Owen M. Baldwin at Arpajon, France. This was surpassed in 1929 by Bert le Vack on a Brough-Superior at the same location. Facing financial hardship amid the recession of 1930, Zenith was acquired by their South London dealer Writers. Later that year, Joe Wright reclaimed the speed record on an OEC motorcycle powered by a JAP engine with a top speed of 137.23 mph at Arpajon.

Shortly thereafter, Ernst Jakob Henne broke this record riding a supercharged BMW at Ingolstadt, Germany with a speed of 137.85 mph. In response, Claude Temple organized another attempt in Cork, Ireland where Joe Wright rode a supercharged OEC machine; after experiencing mechanical failure on that bike, Wright switched to a works supercharged JAP-powered Zenith as a backup and set a new world record of 150.65 mph. Despite Zenith being temporarily inactive and OEC financing the endeavor, this record-setting performance by Zenith often went unrecognized in contemporary media coverage and official FIM documentation.

Eyewitness testimonies including those from Freddie Barnes and later verifications have confirmed Zenith’s critical involvement in achieving this landmark speed record.

Models

Model	Year	Details
Zenith Bi-Car	1903	Hub-center steering with complete suspension system
Zenith Tri-Car	1908	Powered by a Fafnir single-cylinder engine
Zenith 'Zenette'	1908	Equipped with a Fafnir single-cylinder engine
Zenith 'Zenette' Tri-car	1908	J.A.P. water-cooled 6HP engine paired with Chater-Lea two-speed gearbox
Zenith Gradua 6HP (770cc)	1911	Features the "Gradua" variable ratio drive belt system
Zenith 3 1/2HP	1911	JAP single-cylinder sidevalve engine, 500cc displacement
Zenith Lightweight	1911	JAP single-cylinder overhead valve (OHV) 250cc engine
Zenith 8HP Twin-Cylinder Racer	1913	JAP OHV twin-cylinder engine with '90 Bore'
Zenith 3 1/2HP Single-Cylinder Racer	1913	JAP OHV single-cylinder engine, '90 Bore'
Zenith Models E, G, J	1914	JAP V-twin sidevalve engines available in 770cc, 1000cc, and 1100cc variants
Zenith Gradua 680 cc	1918	Powered by a JAP twin-cylinder engine
Zenith-Bradshaw 494cc	1922	Oil-cooled Bradshaw horizontally opposed engine configuration
Zenith "Brooklands"	1923	Equipped with a 344cc JAP engine
Zenith 346 cc	1924	JAP engine utilized for powertrain
Zenith 680 cc	1926	Side-valve JAP power unit installed
Zenith C5 Special 500 cc	1936	JAP OHV engine with a displacement of 500cc
Zenith 750 cc	1948	Fitted with a JAP engine

The Zenette series introduced an advanced rear suspension system during an era when most motorcycles did not incorporate such technology. This design resolved issues related to belt tension by placing the pivot point of the swinging arm near the engine's center and mounting the engine directly on this arm. Additionally, the Zenette was notable for its unique layout, positioning both the fuel tank and battery behind the engine compartment to enhance frame efficiency.

See also

• List of car manufacturers of the United Kingdom
• List of motorcycles of the 1910s
• List of motorcycles of the 1920s
• List of motorcycles of the 1930s