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The terms "suicide clutch" (or "jockey shifter") refer to a motorcycle foot-operated clutch and hand-shifter to change gears,〔 "U.S. Pat. No. 1,110,249 issued to Bailey, which uses a jockey shift handle adjacent to the seat to shift gears, while clutching is achieved by means of a foot operated pedal above the left foot peg or floor board. This combination has proven precarious and is commonly referred to as the suicide shifter." See also 2004/0182669 A1, 192003570; 192003620; 19209900S〕 found on early designs from around the turn of the 20th Century to the 1940s or 50s, and reappearing on modern retro styled custom motorcycles and choppers. Modern motorcycles do not require removing a hand from the handlebars to operate the clutch or to shift gears, using only the fingers for the clutch and the toes of one foot to select gears. In contrast, the fanciful slang "suicide" was applied to designs where the rider removes one hand to change gears, or cannot put both feet on the ground while using a foot clutch to disengage the transmission. Sometimes the shifter is referred to as a "jockey shifter" while the foot clutch is called a "suicide clutch". 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, so they could place both feet on the ground when stopped. 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 is sometimes called a suicide shifter. The suicide clutch is a foot-operated clutch that is mounted on the left side of the motorcycle's forward foot controls.〔 The suicide-clutch moniker has derived from difficulties in operating this form of clutch and shifter. On a motorcycle equipped with a conventional hand clutch and foot shifter, the rider places the left foot on the ground when stopped and holds the motorcycle in place with pressure on the rear brake pedal with the right foot, while engaging the clutch with the left hand. On a motorcycle equipped with a suicide clutch, the clutch is held in with the left foot, requiring the right foot to hold the bike in place, with the right hand applying pressure to the front brake. Early Harley Davidson foot clutches used a spring to return the clutch pedal to the disengaged position and used a friction disc to allow the rider to adjust the sensitivity of the return. Often riders removed the spring to keep the clutch pedal from returning to the disengaged position while riding. While this spring removal allowed for the clutch to stay engaged better, it also removed the safety feature of the clutch pedal holding itself in the disengaged position. With the pedal not returning to its natural disengaged position, the rider must either shift into neutral or hold the clutch pedal with the left foot when coming to a stop. Early Harley Davidson racers removed the clutch return spring to ensure the clutch stayed in the engaged position throughout the race. This practice soon caught on with other riders. The term "suicide clutch" was coined by those who could not operate the foot clutch proficiently enough to ride a tank shift (or hand shift) motorcycle in normal traffic. ==Types of shifters== Regular clutch hand Shifter - This is where the shifter is a regular knob and involves the semi-complex task of two-handed shifting. One hand is used to press the clutch lever on the handlebars and the second hand is used to shift gears. Clutched Shifter - This shifter has a clutch lever on it allowing one-handed shifting. This design allows the left foot to be free. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Suicide clutch」の詳細全文を読む スポンサード リンク
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