Bradbury Motorcycles

Today in Motorcycle History

Bradbury Motorcycles 1914

A CHAIN-DRIVEN BRADBURY.

THE 4 h.p. Bradbury can now be obtained with chain drive throughout, and a three-speed counter-shaft gear, which is mounted below the bottom bracket, and incorporates a kick-starting mechanism. The bolts which hold the gear box are allowed to slide in slots for the purpose of chain adjustment. The gear operating lever is mounted on the right-hand side of the tank in a convenient position, and clipped to the top tube.

The clutch is handle-bar controlled by means of a Bowden wire. The well-known Bradbury method of combining the crank case with the frame is retained, and the latter is strengthened by a strut from the saddle tube to a point behind the gear box. The front mudguard is well valanced, and the rear guard has a small side flap, which will protect the chain to some extent from the mud thrown up by the wheel. The chains of both the single and twin models have covers which protect the top layer of the chain and partially screen the inside of the chain links, but the drive is not totally enclosed.

The 6 h.p. twin machine, which we also illustrate, remains much as last year. The magneto is well protected by a metal guard and mounted just above the ample silencer, which has a pipe to the rear under the left footboard. The latter is of aluminium, and nicely shaped. The engine, which has detachable cylinder heads, is 74½ mm. x 86 mm. bore and stroke, 749¾ c.c.

There is an internal expanding brake in the rear hub actuated by a pedal applied by the left toe. The chain adjustment is very substantial in its construction. B. and B. carburetter and Druid forks are fitted to both models.

A third Bradbury is the 3½ h.p. horizontally opposed twin of 499 c.c, which is also supplied with a three-speed gear and chain drive. This should prove a very attractive solo mount, and be capable of drawing a sidecar if required.

The Motor Cycle, November 26th, 1914. p599

A 4 h.p. Three-speed Bradbury.

89x89 MM. ENGINE; COUNTER-SHAFT GEAR AND CHAIN DRIVE.

THE latest model Bradbury is a type eminently suitable for sidecar work, and in general appearance is something like the 4 h.p. two-speed model. The engine is the standard 89 x 89 mm. 4 h.p. single- cylinder, having a cubic capacity of 554 c.c. As usual, it is mounted in the frame in the distinctive Bradbury fashion, but an auxiliary stay makes a triangle with the seat tube and the bottom bracket. This arrangement forms a sound bed for the three-speed counter-shaft gear, which is of the single sliding member type, with dog clutches to engage the high and low gears. Both gearshafts run on ball bearings, and the ratios provided are 5.1, 8.4, and 14.8 to 1.

The clutch is of the cork insert type, and is controlled from the handle-bar; a gear and quadrant kick- starter is fitted. The drive is by chain throughout, and the gear box is arranged to slide on the bottom bracket so as to provide a simple adjustment for chain stretch. An excellent internal expanding brake is carried on the rear hub, and is of such a diameter as to allow of smooth action and full power. The machine is well fitted up, and the specification includes aluminium foot-boards, two stands, extra heavy tyres, pan seat, and sensible mudguards.

The Motor Cycle, August 6th, 1914


If you have a query or information about Bradbury motorcycles please contact us