变速车的变速系统由多级链轮、多级飞轮、拨链器和链条组成,骑车者通过扳动手柄让前后拨链器左右拨动链条而变速。变速应在骑行中进行,不可在滑行或静止状态下拨档。变速换档最好逐级拨换,可以从最低速级换至最高速级,但切不能一下子从最高速级跳至最低档。选档在不影响预选速度 The speed change system of the speed changer is composed of a multi-level sprocket, a multi-stage flywheel, a derailleur and a chain. The rider shifts the front and rear derailleurs to move the chain to the left and right by pulling the handle. Speed ​​change should be carried out in the riding, not gliding or stationary dial. Shift the best shift step by step, you can change from the lowest speed to the highest speed, but can not suddenly jump from the highest speed to the lowest gear. Select the file does not affect the preselected speed