The history of wheels 4
From 1930 onwards, the tyre was given a cross-tread (see picture), to increase the grip on the road. After being made aware of the increasing noises, the deep tread on the edges of the tyres, e.g., were arranged in an
irregular order. This was followed by the first phase of speed-records, which ended at little more than 400 km/h, Indeed, heavy demands were made on the tyres.
The tubeless tyre was successfully developed, through an additional sealing on the rim and on the inside of the tyre. These were easier to mount and above all, they were more safe in everyday use, because e.g., there
was no longer any friction between the inner-tube and the tyre. The disadvantage was, that particularly later on as a radial tyre, a bead on each side was necessary, to prevent it from slipping into the drop-center when
cornering or through the loss of pressure.
At the same time, Michelin invented the first radial-tyre, which would only assert itself generally much later. In this case, the tread-surface was much more stable than the flanks were, partially
because steel wires were worked into the carcase. This promised less rolling friction and more stability when cornering. The lower springing effect was
compensated for by the vehicle's suspension.
The race for the record-breaking of the 1930s was taken up again. This time, in test runs, where they were pushing for speeds of up to 500 mph, which means approx. 800 km/h. An additional problem for the tyres was
(see picture), that the tests took place on salt-flats. At least the crew did walk the track beforehand to remove any potentially dangerous objects.
In the 1970s, the subject of aquaplaning (see picture), became very acute. This was the time of the negative steering radius, which at least, did properly influence the steering in the event of unequal traction. Later on,
ABS was introduced, however, the subject of sufficient tread as the best possible protection against aquaplaning, was still the order of the day. Since then, it is no longer permitted to change the tyres crosswise.
Nowadays, the rolling direction is often prescribed anyhow.