...when you slide and have no control of direction and speed. Hit my first patch of ice for the winter this morning, on the wee path that breaks off the main pavement at the South side of the Forth Road Bridge, just before the petrol station. Didn't spot it at all. Wasn't going more than about 10kph but turned my wheel and carried on in straight line, as rear wheel slid sideways for a metre or two. Managed to stay upright but totally lost any faith in tyres for rest of ride in, horrible feeling!