AJS - compresseur A/C
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AJS D2-492-78-08
Photo ou archives : M. Woollett

Capacity : 1000
Model : compresseur A/C
Production : 1930 - 1931
Category : (R) Racing - Record


1000cc Supercharged V-twin – 1933

Frustrated attempt

Inspired by the world records - including a flying kilometer covered at 119 mph - set by a specially-prepared 500 single ridden by Bert Denly at Arpajon in August 1929, AJS decided to attack the absolute motorcycle speed record in 1930. Project leader was Jack Stevens, eldest of the five brothers who had founded the company, with Nigel Spring as team manager and Oliver Baldwin as rider - Bert Denly being judged too small for a 1000cc bike!

Special V-twin

The engine used two cylinders and heads built for the 500cc record-breaker. Each had a chain-driven ohc mounted on a special bottom-end.

Forced Induction

Baldwin reached 132 mph at Arpajon on the naturally-aspirated 1930 version of this bike (70 hp and a compression ratio of 11.5:1), but Joe Wright beat this record on his OEC-JAP with 137 mph. AJS fitted a supercharger, but (since the marque went into liquidation) the project was shelved for over two years, until Matchless bought AJS. By the time the reorganization was complete, Ernst Henne's BMW had raised the record to 152 mph. Even so, AJS signed Wright for a new record attempt on Southport Sands. But the official chronometers of the FIM, which had been sent from Germany, were held up by British Customs and the best time that was achieved was only 135 mph. Then bad weather and a broken valve halted the record session. In late 1933, the AJS made a further attempt at Tat (Hungary), reaching 145 mph, and was then sold at a low cost to Charles Mortimer, father of modem Yamaha rider Chas Mortimer.


Engine: 996cc (79x101mm) air-cooled V-twin four-stroke; ML magneto

Power Rating: 80 hp @ 6200 rpm

Valves: chain-driven overhead-camshaft to each cylinder

Fuel System: chain-driven PowerP!us supercharger; carburetor

Transmission: Sturmey-Archer 3-speed, chain final drive

Suspension: friction-damped girder forks (front); rigid (rear)

Brakes: drum (rear)

Wheels: 23 inch (front); 20 inch (rear)

Weight: 423 lb

Maximum Speed: 145 mph

Discovered in Tasmania and brought home to England, the supercharged A]S 1000cc V-twin has been restored to its original condition.

Motorcycle encyclopedia Moto Passion, realised by François-Marie Dumas, include almost 2000 photos presented with an exhaustive history of the motorcycles exhibited.

This unique collection has been realised with the participation of many specialists. With many thanks in particular to Yves Campion, Michael Dregni, Didier Ganneau, Jean Goyard, Helmut Krackowizer, Michel Montange, Christian Rey, Bernard Salvat, Mick Woollett, etc

One can order here

  • Original cards on paper (in french)
  • High resolution scans or original documents presented and signed with my name.

Please contact me at info@moto-collection.org for conditions and copyright.

© Tous droits réservés
François-Marie Dumas

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