More technically, "suicide clutch" can refer to clutch controls lacking a detent on the foot clutch, which would otherwise allow the rider to lock the clutch in the disengaged position. Early foot-clutch motorcycles, such as those from Harley-Davidson and Indian, allowed the rider to lock the clutch foot pedal due to its over-center geometry plus a helper spring (aka "sissy spring"), so they could place both feet on the ground when stopped. These standard clutches are called a "rocker clutch". If this device was disabled, or a custom foot clutch was installed that had no detent, it was referred to as a "suicide clutch" because stopping the motorcycle in-gear required the rider to keep his foot on the pedal. Should he lose his balance and put the left foot down, the motorcycle could lurch forward into cross traffic. The suicide clutch, especially on a chopper with no front brake, also made stopping at a red light on a hill especially precarious.