Chapter 6

Motor Tricycles

The motor tricycle made its first appearance in England at Sir David Salomons’s show of motor cars at Tunbridge Wells in 1895. It consisted of a strongly-built tricycle with pneumatic tyres and a small petrol engine (with the air-cooling ribs) at the back, the main features of the motor tricycle of to-day. The machine is patented by MM. de Dion and Bouton, but, as far as the writer can see, the only patentable part seems to be holding the cylinder head, and cylinder to its base or crank case by four long studs.

Fig. 17 shows a motor tricycle made by the Motor Mannfactoring Co., Ltd., of Coventry. The cylinder C is kept cool by ribs cast round it, which expose a large surface to the air, in the same way that the ribs of a Gurney stove heat the air in our churches and halls. If it were not for these radiating ribs on the stove its cast iron fire-box would soon become red hot. In like manner the ribs cool to a certain extent the cylinder of the motor. A is the crank case. The crank is built up by means of the two fly-wheels, which almost fill the case, the crank-pin holding the two together, and the fly-wheels forming the cheeks of the crank. B is the casing, made of aluminium; it contains a small quantity of oil; the rotary action of the fly-wheels, acting as a centrifugal pump, carry the oil round the case, dashing some up to the cylinder to lubricate the piston; some runs into two gutters cast in the interior of the case, from whence it runs to the main bearings. The crankshaft carries on one end the pinion with twelve teeth (not shown in the sectional drawing), which gears into a large wheel with 106 teeth on the main axle. This latter is in the casing D. The exhaust valve is worked by a cam on the second motorshaft. The carburetter is the triangular case under the saddle. Air passes down the slightly-inclined pipe F and, passing over the surface of the petrol, becomes carburetted; it then passes off through the adjusting cock H to the cylinder.

Fig. 20 is a diagram showing the interior of carburetter. The pipe F is made to slide up and down. Air passes down this pipe under the baffle-plate S across the surface of the petrol, where it absorbs the vapour, and up to the three-way cock H, then by the pipe to the engine. The pipe X takes a small portion of the exhaust through the petrol, to heat same in cold weather. R is a float carrying a wire to show quantity of petrol in the carburetter.

In front of the rider on the upper tube of the machine are three handles. The aftermost one J is for adjusting the vapour and air; the next L is for opening a cock on cylinder to take off compression for starting; the last K is for shifting, advancing or retarding, the point of igniting the charge. The battery for working the coil consists of four dry cells. One wire from these is led up to the left-hand handlebar, and with the handle (which rotates) forms a switch for putting on or off the electric current, and so stopping the engine. The wire then passes to the trembler or interrupter and to the coil. The machine is started by pedalling it for a few yards, and by manipulating the handle J to adjust the mixture of air and petrol vapour. The mixture fires as soon as the explosions commence, the compression cock is shut, and the engine takes up the driving, the driving wheels running free of the crank. The gearing is low, being only about 36in. The induction coil is fixed to the main axle; it is not shown in the section, but in the back view both it and the exhaust silencer are shown. The differential gear is contained in the boss of the large tooth wheel. Two brakes are used - one on a drum on the steering wheel; the other on the back axle.

The following are the principal dimensions of this machine: Diameter of crankshaft, 13-16in. Diameter of cylinder, 2 3/4in. Stroke of piston, 2 3/4in. Diameter of flywheel, 7 7/8. Width of flywheel, 1 in. Wheelbase, 3ft. 6in. Wheels, 2ft. 2in. Diameter of cylinder over grills, 4 3/8in. Ratio of gearing, 1 to 8 5/6. Tyres,2 1/2in. Gauge of driving wheels, 3ft.  Extreme length, 5ft. 10 1/2in. Extreme width over mudguards, 3ft. 5 1/2in.

The quadricycle is a development of the motor tricycle, the single steering wheel being removed and replaced by two steering wheels on an Akermann axle, the seat for the passenger being between the front wheels.

Many quadricycles and motor tricycles are fitted with water-cooled cylinder heads (or combustion chambers). These appear to have considerable advantages on long runs and in hilly country. The water is carried in a division of the petrol tank, which is made much larger than usual, and to prevent the heat from the hot water reaching the petrol there is an air space between the two, and holes drilled in the circumference of the drum allow air to pass freely through this space.

Another method by which a motor tricycle can take a passenger other than the driver is by attaching to it a trailer - a light two-wheeled car. In this arrangement the passenger is entirely free from the vibration of the motor. Trailers for carrying parcels are coming into use. The writer lately saw one fitted with a platform about 5ft. long and 3ft. wide. It was intended to carry the light baggage of soldiers on the march or on manoeuvres.