Quick release skewers are rods which are threaded at one end with a cam assembly on the other. This combines to make a lever operated cam system. The quick release mechanism was invented in 1927 by Tullio Campagnolo who was an Italian bicycle racer. He was frustrated when he needed to repair a flat tyre during a race the weather had turned cold and his hands were numb so he could not operate the wingnuts which retained the wheel. He had been well-placed prior to the puncture but lost valuable time so decided to develop a quick release skewer system which enables simple wheel removal in seconds.