A World without Tyres, Part 2 – Entering the 20th century on air and thread patterns

Official press release from Continental AG

From 1888 onwards, use of pneumatic tyres became increasingly widespread. After all, they promised considerably more comfort and grip than their solid rubber, iron or wooden predecessors. Air is wonderfully springy and rubber provides better grip. Even though the sharp stones, nails and shards on the roads meant that travel rendered them especially susceptible to puncture, more and more cyclists switched to them. At that point, tyres had no thread patterns on them. The wide range of grooves and lug structures common today had not been invented then. If the road was slippery – for whatever reason – cyclists either dismounted or ended up in the ditch.

The inventors in the tyre industry were, though, already working on this problem. In its issue no. 204 from 1894, the German magazine ‘Der Radmarkt’ (‘The bike market’) ran an article on Continental’s new ‘anti-slipping’ tyres – the first tyre with a thread pattern. Its smooth thread with flat longitudinal strips was claimed to “definitely prevent slipping”. The magazine went on to say that “As a result, greatest speed can be achieved” and “this will prevent faeces from being flung upwards.” (ed: Faeces means sh*t.) Aha, so that was what made the roads slippery. (ed: No sh*t!!) Dismounting was therefore strongly advised if one did not have ‘anti-slipping’ on one’s rims. Thus began the triumphant advance of the thread patterned tyre, initially on bicycles.

In 1899 production of car tyres began in Hanover – designs that were essentially bicycle tyres with suitable dimensions and greater load capacities. They still had no thread pattern – lateral forces were, after all, limited – and at average speeds of around 15 km/h (9 mph) a proficient cyclist could easily overtake the early cars. At that point ‘aquaplaning’ did not even exist as a term. In 1908, a good 34,000 cars were registered in Germany – and only 65 of these had over 40 hp. However, for these few it was still worthwhile continuing development of the product ‘car tyre’. And so in 1908 the first car tyre with a thread pattern appeared on the market. Continental presented this ‘epoch-making innovation’, also referred to as ‘anti-slipping’, as the ‘grooved’ model. The first grooved pattern is visible on the flat thread area.

Pure grooved thread patterns are still used today for certain applications, such as Formula One. Continental already had a tyre model in its range with ‘rivet skid protection’ in 1905 – the rivets fixed to the thread were supposed to give greater protection from stones and nails.

And on slippery roads, the tyre was designed to provide better grip. Rivets used as studs can still be found on tyres today. Although they have virtually disappeared from use in Central Europe, many motorists in Scandinavia still rely on studs to give them the best grip on icy roads.

In the period that followed, the thread pattern continued to evolve. As the thread grooves became wider, the engineers made square incisions in the ridges – and so the first thread lugs came into being, providing grip for cornering. However, that made the tyres noisier and to get around this, the first directionally-orientated thread pattern was used on the Continental balloon tyre in the late Twenties. Gradually other manufacturers included tyres with offset rows of thread lugs in their ranges. At the same time, tyre design became ever more elaborate, with sophisticated manufacturers’ logos and tyre designations on the sidewalls. They were, however, a long way from adding the standardized information commonly seen on sidewalls today. The first winter tyres, developed by Semperit in 1938 and designated ‘Goliath’, had a highly distinctive lugged thread pattern that interlocked well with snow, enabling motorists to make good progress on roads which those days did not get cleared.

From the Fifties onwards, it was a case of ‘anything goes’ in tyre design – zigzag patterns, trapezoidal, dumbbell- or S-shaped lugs, they all had their advantages and drawbacks in summer and winter use. In 1969 Uniroyal launched the first rain tyre – the rallye 180. When studs were banned, tyre lines featuring sophisticated sipe systems became the winter specialists, getting well-established from the mid-Seventies onwards. Sipes – fine incisions in the thread lugs – developed in many different directions and their shapes became ever more complicated – culminating in Continental’s elaborate, offset cross-linked sipes. What they all had in common was that under load – i.e. during setting off, braking and cornering – they formed large numbers of gripping edges, thereby providing increased traction.

The work of tyre developers in this field began to be driven by changes in conditions. Cars rarely had to travel on loose snow in winter, as the roads were usually cleared or the layers of snow were firmly packed. So tyres had to have more edges to be able to brake the cars, which were getting ever faster and heavier, and keep them going in the right direction. To carry out this task even more efficiently, the first asymmetrical tyres were launched at the end of the 20th century, with the thread pattern now designed according to the respective ‘function’. The right, left and centre sections of the thread pattern were highly specialised and designed for different tasks, with each area responsible for transmitting steering commands. Such designs were developed for summer and winter tyres. However, anyone looking for sporty driving performance and for fast dispersion of water from the ground contact patch would opt for the V-shaped thread pattern – this not only looks stylish, it also reduces the risk of aquaplaning.

The thread pattern has now been around for 101 years and its evolution has been a turbulent one. The experts predict its development to continue, so that it can offer even more grip, disperse water even more efficiently and become quieter still. So things remain exciting in the field of tyre design. And hopefully also in the next issue of ‘A world without tyres’, where synthetic rubber is to make its debut.