The Evolution of Cartwheels

Part 3 :: The Final Designs

Part 1 | Part 2

Evolution of design, of course, never stops when there is a new need to fulfil, or a new material to fulfil it. But, in the case of the cart wheel, its last task was to provide the first wheels for the "horseless carriage" and its offspring. Perfection of wheel designs for horse-drawn transport, occurred between the years of 1700 to 1900.

Three significant changes had taken place by mid eighteenth century. The nave had almost doubled in diameter and was now asymmetric because spoke mortises were cut close to the inner end, so that spokes could be deeper in section. This meant that leverage on the axle was reduced; and it could be coned, increasing the diameter just where the greatest strain occurred.

Secondly, in the large nave there could be more spokes, and they were inserted at an angle to each other to create triangulation, the "dish." This greatly increased the rigidity and strength of the wheel. To make the bottom spoke vertical when it carried most of the load, the coned axle was canted down. Narrow tyres ran well enough, but broad felloes had to be coned to stand flat on the ground. Broad coned tyres were difficult to make and they scuffed the surface. So began an argument as to the best angle of dish and wheel breadth which was not resolved until a completely different design took over in the late nineteenth century.

Last but by no means least, at the beginning of these changes, some genius hit upon fitting two spokes to each felloe. They had to be sprung into place with a tool called a "spoke dog," but once there, they locked the felloes together so that they couldn’t vibrate apart. The heavy fastening plates were no longer necessary, nor was the tyre relied upon to hold the felloes together, though of course it was of great assistance.

Wheels built up to 1850 were more or less made to this pattern, though the number of spokes increased, they were staggered alternately at the nave, increasing triangulation and the tenons on their outer ends became round instead of square.

By 1850 the Industrial Revolution had gathered momentum, iron was plentiful and steel was now readily available. The old, all wooden axle tree had been superseded by cast iron stub axles set into a wooden exbed and oil became the lubricant, replacing tallow.

Next came the all-metal undercarriage, and coned axles were replaced by cylindrical ones made of steel. The lynch pin was discarded in favour of three bolts which secured the wheel to a back-plate, called "Mail axles", though they were also used on fast road vehicles, and the wheels of light carriages were held on with left and right handed nuts.

These developments relied upon the introduction of springs to lessen the impact, as the gross weight of a waggon hit a bump in the road. At 4 m.p.h. such blows were unimportant and first attempts at springing in Elizabethan times were aimed at reducing the jolting for passengers in carriages, by hanging the coach body on posts on leather straps. The posts became laminated wooden strips, which became laminated metal strips. There were elliptical springs from 1804, culminating in the semi-elliptical spring for both light and heavy commercial vehicles. Hancock produced vulcanised, solid rubber tyres in 1846, which came into favour for light vehicles before they were replaced by Dunlop’s pneumatic tyres after 1888.

Artillery (left) and Mail Coach Wheels

So far all these wheels had been drawn by horses; none had to transmit power from the axle to the ground. However, a very rugged wheel had been developed for army artillery pieces. In place of the nave, the spokes were tapered and ran right to the axle with no spaces between them. They were held in position by two plates which were bolted together. The spokes could be dished, but it was more economical to set them straight. It was these last wheels which were ideal for the transmission of power and, shod with solid rubber tyres, became the first motor lorry wheels.

Village wheelwrights worked in spendid isolation until prefabricated, standardised parts became available in the second half of the nineteenth century and so, as each man developed his own style, his own trade-mark, there arose recognisable patterns of regional design. This was true of carts and waggons alike, but, because the waggons represented the aspirations of the wealthier farmers and land-owners, the designs which amounted to an art-form, were more obvious to see. Of course, some wheelwrights were more successful than others and their trade enlarged at the expense of the "little man." Eventually the large firms converted to factory methods, and batch production led on to full scale mass production lines.

Uniformity, economic efficiency and mass-markets are considered to be the cornerstones of modern manufacture, though without built-in obsolescence, the system grinds to a halt. Village craftsmen working as a family group, declined as they could no longer compete. Early carts and waggons were vehicles of obstinate glory. Each shire produced its own unique, idiosyncratic variations; younger developments bore the dull uniform stamp of mass-production.

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