John Sipe worked in an abattoir in the US in the 1920s. Like other workers there he found that he kept slipping on the wet and bloody floors. His shoes were too slippery, so he took his knife and cut thin slits across the rubber soles. He found that the shoes now gave a much better grip. In 1923 he took out a patent on the process and called it Siping with the slits called Sipes. He thought it could improve the grips of car tyres and he was right but unfortunately for him Siping was not adopted by the motor industry until the 1950s when superior tread compounds were developed that could stand up to the process.
On roads covered with snow, ice or water Sipes in tyres significantly improve traction. A 1978 study by the US National Safety Council found that on ice Siping improved stopping distances by 22 % and rolling traction by 28%.
The car tyre industry and Formula One in particular developed Siping and nowadays leading shoe manufacturers borrow ideas from racing car tyres to make their shoe soles grip better – so the idea has come full circle. Incidentally the reason the Sipes work is not because they carry water away; they make the sole much more flexible and allow a bigger area of contact and grip.
Based on a chapter in Think like an Innovator by Paul Sloane published by Pearson.