Speedway Workshop

The Comerford "Special"

In the early days of dirt-track racing Messrs. Comerford-Wallis Engineering Co.Ltd., of Thames Ditton, Surrey, produced the Wallis Dirt-track Special, a machine which was used to a considerable extent. It was designed to take almost any standard racing engine of 350cc. or 500cc. Outstanding features in its design were the short wheelbase frame, embodying the
Wallis patent lug wherever great strength was required, a special design of racing forks with a very short movement, and the provision of nuts requiring only two spanner sizes for the whole machine.

However, as far back as 1929, when the Wallis was produced, it was obviously impossible to design a dirt-track machine approaching anything like perfection. Since those carly days a large amount of data has become available, and the above-mentioned firm, after carefully considering the defects in the original Wallis and much experimenting, have evolved a machine which, although incorporating the best characteristics of the Wallis, is in the main an entirely new design. It is known as the Comerford-Special. During 1932, this machine, sometimes referred to as the "Hush-Hush" type, gained much prestige in the dirt-track world, and is being manufactured for 1933 with very slight alterations,
which consist of a slightly longer wheel base and more flexible rear stays, so as to improve further the stability of the macliine when broadsiding.
The Comerford-Special has thc following specification.
Frame and Forks.-the sturdy design of the frame, which is coslettised
and enamelled black. A single front down tube is used, but this, at its upper end, is joined to a particularly massive steering Head of forged steel.

Incidentally, all lugs are drop forgings and every joint is brazed. Reynolds Aero qaulity cold-drawn steel tubing is used throughout. The rear forks and seat stays incorporate the Wallis patent lug, which gives immense strength.
The fork has a pair of very stout and dead-straight blades, braced at the front by two thinner members arranged so as to constitute a rigid girder able to resist all torsional stresses. There are no side links whatever, the springing
being of a novel design. The fork blades at the bottom have telescopic prong members with internal springs. As may be noted in the illustration, the fork action is limited by flanges on the lower telescopic members to a very small movement. Immediately in front of the heavy upper lug joining the main fork blades is a split lug for mounting the handlebars, thus providing a good forward position and adjustment for any desired angle. A special shock absorber is provided, in addition to the Andre steering damper over the steering head.

Tank. - The tank, which is originally distinctively panelled in red, is mounted on rubber insulators to protect it from damage. It holds 1 gallon of fuel and 1 quart of oil. On the left-hand side is a Bestand Lloyd positive hand-operated pump with a 5/16-inch oil-pipe union for connecting the mechanical pump on the engine.

Transmission. - A countershaft is provided, but no clutch. The countershaft, which is a 7/8-inch-diameter nickel-steel shaft, is mounted on Timken tapered roller bearings, carried in a cast-aluminium housing. The two sproekets are splined to the coutershaft and have 42 and 15 teeth. Hans rynold chains of extra heavy type, maesuring 5/8 x 1/4 inch, are used for both primary and secondry transmissions, but a 5/8 x 3/8 inch chain is also available for the secondry drive, which may be arranged on the near or off side at the riders option

Wheels and Tyres. - The wheels, which are chromium plated with heavy rims and 10-gauge spokes, have Timken tapered roller-bearing hubs, and the front one has a knock-out spindle. The chain wheel has 52 teeth. The wheels are shod with 2 3/8-inch Avon or Dunlop dirt-track tyres.

Miscellaneous. - Included in the specification are dropped racing-type chromium-plated handlebars, which are adjustable for angle and provided with an Amal twist-grip for the throttle, with dummy to match; a special Lycett narrow Aero seat with three-point suspension; a quickly detachable rear stand of pressed steel; a lifting handle made of steel strip with mudguard running between this and the bottom chain stay ; a quickly detachable, rubber-covered foot rest, and a knee hook.

THE COMERFORD-SPECIAL JAP MACHINE

Messrs. Comerford-Wallis Engineering Co. Ltd, who, it may be mentioned, are distributors of Jap racing engines, market besides the Comerford-Special frame assembly and the Comerford racing forks, a complete machine with a 498c.c. single-port Jap speedway engine, inclined slightly forward in the frame. This machlne, is known as the Comerford-Special Jap. It has a large-diameter straight-through exhaust pipe, a twin float chamber, Amal carburettor with triple-gauze filter, and a racing B.T.H. magneto with platinum-iridium contacts.
 

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