Many newcomers are not too clear about the difference between 21-speed, 24-speed, and 27-speed. Only know that 21 speed is 3*7, 24 speed is 3*8, 27 speed is 3*9, and the speed change option is bigger. Many novices are also asking whether 24 speed is faster than the 27 speed. Some people ride a vintage iron mountain bike with other people running behind, there is understanding that you do not follow the run, people are 27 speed, you run but others. In fact, the speed ratio only gives the rider more choice opportunities. The speed is based on his own leg strength and endurance. As long as you have great strength, 21 speed is not slower than 24 speed! How much can a mountain bike ride? In theory, the same cadence is faster than 27 to 24, and 24 is faster than 21. However, in fact, the high transmission ratio is very heavy, and the cadence will naturally be reduced. The cadence will be lowered and the speed will naturally drop, failing to reach the theoretical speed. Or novice newbie bought a car and said that my car is good. How my car is so burdensome that you did not choose a suitable transmission ratio for your ride. Let's talk about the personal understanding of 21-speed, 24-speed, and 27-speed differences. Please enlighten if you do not:

First look at the parameters:

21 speed gear wheel 48-38-28 flywheel 14~28

24 speed gear disc 42-32-22 flywheel 11~30(11~32)

27 speed gear plate 44-32-22 flywheel 11~30 (11~32)

The number of gears divided by the number of flywheels is the gear ratio

21-speed maximum gear ratio 3.43, minimum transmission ratio 1

24 speed maximum gear ratio 3.82, minimum gear ratio 0.73 (0.69)

27-speed maximum transmission ratio 4, minimum transmission ratio 0.73 (0.69)

From this we can see the difference between them. The 27 and 24 speeds are larger or smaller than the 21st speed, which can make you run more and make you run more easily. Because the 24 sprocket is not the same as 21, the smaller sprocket can get a lighter transmission ratio, which shows great advantages when climbing a hill. Even if the 24 speed car uses 2*1 speed ratio, it can reach the transmission ratio of 1.07. If the flywheel is 11~32 cars, it can achieve the transmission ratio of 1 (the 21st speed minimum transmission ratio is 1). Therefore, the advantage of 24 speed than 21 speed is not only in the fastest file, but more in the slowest file, which makes it easier for you to go to the mountain. While ordinary newbies only want 24 speeds faster than 21 speeds, there may be few people who divide each gear and flywheel tooth count to see what is different.

Many people buy a good mountain bike, usually only in the city running highways, riding commuting, more afraid of losing, the number of days of cycling in the year are limited, in fact, is really a waste of good cars. The car is for people to ride is not a treasure. The design of a good mountain bike is justified. The mountain bike itself is born for the mountain road. If there is a novice to buy a car, it is a city to run flat roads, then you can buy a city RV or a road bike.

27 speed car, it's flywheel is generally the same as the 24 speed, the only difference is that the front gear plate is adjusted from 42 to 44, so the big gear plate under the 9 speed ratio must be larger than the 24 speed, suitable Physically good people. Another 24-speed or 27-speed with its different grades, the car's various accessories are also upgraded to a better model, which is also different.

Also say that the small wheel folding bike is not suitable for running mountain roads, it is only suitable for places with better road conditions. The bmx is not slow to run but it is not safe to run on the mountain road. It is very easy to crash when it encounters bad road conditions or sudden braking.