CHICAGOMOTORSPEEDWAY

Flat spot: The term given to the area of a tire that is worn heavily on one spot after a moment of extreme braking or in the course of a spin. This can ruin its handling and often cause severe vibration which may ultimately force a driver to pit for a replacement set of tires. Formation Lap: The lap before the start of the race when the cars are driven round from the grid to form up on the grid again for the start of the race. This is also sometimes referred to as the warm-up lap or parade lap.G-force: A physical force equivalent to one unit of gravity that is multiplied during rapid changes of direction or velocity. Drivers experience severe G-forces as they corner, accelerate and brake.Graining: When a car slides, it can cause little bits or rubber (or ‘grains’) to break away from the tire’s grooves which then stick to the tread of the tire. For the driver, the effect is like driving on ball bearings; however, careful driving can clear the graining within a few laps, but will still have an effect on the driver’s pace. Gravel Trap: A bed of gravel on the outside of corners designed with the aim of bringing cars that fall off the circuit to a complete halt.Grip: The amount of traction a car has at any given point which affects how easy it is for the driver to keep control through corners.Installation Lap: A lap done on arrival at a circuit to test functions such as throttle, brakes and steering before heading back to the pits without crossing the finish line.Jump Start: When a driver moves off his grid position before the five red lights have been switched off to signal the start. Sensors detect premature movement and a jump start results in a penalty.Left-foot braking: A style of braking made popular in the 1990s following the arrival of hand clutches so that drivers could keep their right foot on the throttle.Lollipop: The sign on a stick held in front of the car during a pit stop to inform the driver to apply the brakes and then to engage first gear prior to the car being lowered from its jacks.Marshal: A course official who oversees the safe running of the race. Marshals have several roles to fill including observing the spectators to ensure they do not endanger themselves or the competitors, acting as fire wardens, helping to remove stranded cars/drivers from the track and using waving flags to signal the condition of the track to drivers.