百科详情

一种能改变链轮与飞轮速比的自行车.它的结构与轻便自行车基本相同，所不同的是在后轴上装有变速机构.变速机构分外变速和内变速两种.内变速自行车采用内三飞变速后轴，有快速、中速和慢速三档.变速动作是通过控制手控三级定位变速装置（前、中、后三档）来实现.外变速自行车采用多齿轮片的外五飞（１５、１７、２０、２４、２８牙飞轮片）与双层结构的双链轮（５２、４８牙链轮片），通过手控无级定位变速装置达到改变传动速比的作用.变速车的特点是可以根据不同的骑行条件而选择相应的速度.骑自行车时最好能保持车速均匀，两脚蹬踏力及频率比较一致.实验证明，人们在骑车时，因受腿部肌肉收缩快慢的约束，一般两腿的回转频率，保持在每分钟６０—７０次，但在骑车时掌握此频率确非容易，因往往受坡道、弯路、风力、风向等因素的不断变化及各种路面的影响，为此，骑车者就得不断改变双脚的蹬力，使之保持某种速度.在自行车上安装变速机件，使车辆在上坡等需要增加蹬力时能增大力矩，在平坦路面上或顺风等适宜增速时能调整速比，使之加速.这是变速车的主要优点.使用变速自行车，以减少骑行时疲劳感的奥秘，就在于人们充分利用了能量变换的特性.变速车还能改善长途骑行中的枯燥乏味感，提高人们骑车时的兴趣.Can change the speed ratio of a bicycle sprocket and the flywheel. Its structure is basically the same bike with the light, the difference is that in the post-axis with speed change mechanism. Exceptionally variable speed change mechanism and the two kinds of internal gear. Within the variable-speed bicycle use within the three flying speed rear axle, with fast, medium speed and slow third gear. variable-speed motion through a three position manual shift control device (before, during and after third gear) to achieve. outside the multi-speed bike gear film outside the 5-fei (15,17,20,24,28 tooth flywheel-chip) and the two-tier structure of the double-sprocket (52,48 tooth sprocket film), through manual stepless speed changing device to change the location of the role of the transmission speed ratio. is characterized by speed, according to different riding conditions to select the appropriate speed. riding a bike is best able to maintain uniform speed, feet Diego more consistent strength and frequency. experiments show that people cycling, due to leg muscle contraction speed constraints, the general legs of the rotary frequency, remain at 60-70 times per minute, but in cycling to capitalize on this frequency is certainly not easy, because often by the ramps, detours, wind, wind direction and other factors changing and various surface effects, for which cyclists have to constantly change the feet of the pedal force, so to maintain a certain speed. to install variable speed bicycle parts for vehicles such as the need to increase pedal uphill when power increased torque, in the flat road or other suitable growth rate when the wind speed ratio can be adjusted so as to accelerate. This is the main advantage of variable-speed cars. the use of variable-speed bicycle, in order to reduce fatigue when riding the mystery lies in the people's full use of the energy conversion features. transmission cars can also improve the long-distance ride in the boring sense, enhance people's interest in cycling.

1.导向系统

2.驱动系统

3.制动系统

^[1]