Web Analytics

 New Imperial - 500 Unit Major Mod. 17
 Back to brands list

New Imperial Unit Major Mod. 17 motocyclette motorrad motorcycle vintage classic classique scooter roller moto scooter
Photo ou archives : F-M. Dumas

Capacity : 500
Model : Unit Major Mod. 17
Production : 1937 - 1939
Category : (R) Street Bike


500 "Unit Major" Model 17 - 1937

Way ahead of its time

Few prewar British motorbikes had unit-constructed engine/gearboxes. If swinging-fork rear suspension was also included in the specification – as on the 1937 New Imperial 500 – the bike was really something out of the ordinary.

Outstanding Sporting Record

Well-known for the outstanding sporting· record of its 250 and 350cc singles, the "New Imp" came from Birmingham – center of the British motorcycle industry – where the company had been founded in 1900. The marque was a technological trend-setter – it used double-overhead cams in 1922, and four-speed transmissions and dry-sump lubrication as early as 1929.

Glorious Swan Song

In the 1936 Tourist Trophy, there was a new bike for works rider Bob Foster. Derived from the 250cc production model, the racer had a unit-constructed engine/gearbox, wet-sump lubrication, and leaked oil so badly that "Fearless Foster" nicknamed it the "Flying Pig Trough." It won the Lightweight TT at record speed, covering the 264 miles of the race at an average of 74.25 mph and crossing the finish line without a drop of oil left in the sump! This ultra-rare 500 was built on the same lines as the 250cc and 350cc New Imps, and was the firm's swan song. The doors closed in 1938. A rescue plan by Jack Sangster of Triumph supported a brief comeback, but the outbreak of World War II

on September 3, 1939 dealt New Imperial its final blow.


Engine: 499cc (86x86mm) single cylinder four-stroke

Valves: pushrod overhead

Fuel System: carburetor

Transmission: 4-speecl, chain final drive

Suspension: (front) girder forks; (rear) swinging cantilever

Brakes: drums

Wheels: wire

Maximum Speed: approx 70 mph

The rear suspension of the New Imperial500 acted on a single helical spring with a friction damper whose settings could be altered while the bike was in motion by a big knob under the saddle.

Le fichier Moto Passion réalisé par François-Marie Dumas réunit près de deux mille photos accompagnées d'un historique très complet des machines présentées.
Il sera progressivement mis à jour ici et toute information complémentaire est la bienvenue sur info@moto-collection.org.

Cette documentation unique, qui constitue sans doute l'encyclopédie la plus exhaustive jamais écrite sur l'histoire de la moto, a été réalisée avec l'assistance de nombreux spécialistes dont principalement Didier Ganneau, Christophe Gaime, Mick Woollett, Jean Goyard, Bernard Salvat, Christian Rey, Yves Campion, Helmut Krackowizer, Michael Dregni, Michel Montange, etc. que je remercie ici.

Disponible sur demande :
- Les fiches originales sur papier
- Les photos et archives signées de mon nom en haute définition ou les documents originaux.
Me contacter sur info@moto-collection.org pour les conditions et droits d'utilisation.