He handcrafted every part
When the wheelwright made wooden wheels for vehicles he handcrafted every part to fit together without the use of nails. The hub was usually made of elm, the spokes of oak and the felloes (ie parts which made up the rim) of ash, elm or beech. When completely assembled, the rim of the wheel needed to be protected from track and road surfaces by fitting a tyre or strakes (shoes) to the rim. This was done by the blacksmith.
The blacksmith bent it into a circle
Strakes were short curved lengths of metal covering the joints between the felloes and they extended from centre to centre of felloes. They were nailed into place. The tyre was different as it was a continuous band of metal shrunk on to the rim. A length of metal bar was laid on the ground. The wheel was run along it to measure the length required for that wheel. The bar was cut and then the blacksmith bent it into a circle and welded the ends together. The inside circumference of the tyre was measured as well as the outside circumference of the wheel to ensure accuracy; the tyre measurement had to be less than that of the wheel. The wheel was then placed down on the tyre platform and secured by a metal toggle. The tyre platform which was usually made of stone, was larger in diameter than the wheel. There was a hole in the centre of the stone to take the hub. The tyre was then heated to red hot allowing it to expand. It was then quickly placed over the wheel and hammered down. It was quenched with water straight away to shrink the tyre onto the rim and bind the various parts of the wheel together. Then the tyre was nailed to the rim. Now the blacksmith put a band on each side of the hub to strengthen the axle box installation.
Tyre platforms now lie abandoned close to many old smithy sites and are often mistaken for millstones.
George Sturt: The Wheelwright’s Shop (1963). Cambridge at the University Press