When it comes to mountain biking, there are a few things that are essential. A good bike, the right gear, and plenty of determination. One piece of...
What is the difference between 21 speed, 24 speed and 27 speed?
Many newcomers are not very clear about the difference between 21 speed, 24 speed and 27 speed, they only know that 21 speed is 3*7, 24 speed is 3*8, 27 speed is 3*9, and the shifting options are bigger. Many newcomers are also asking if 24 speed is faster than 27 speed. In fact, the speed ratio only gives the rider more options, the speed is dependent on your own leg strength and endurance, as long as you have a lot of power, 21 speed is not slower than 24 speed! How many mph can I ride a mountain bike? Theoretically the same pedal 27 faster than 24, 24 faster than 21. But the fact is that the high transmission ratio pedaling is very heavy, pedaling frequency will naturally reduce, pedaling frequency down, the speed naturally also down, not up to theoretical speed. The following talk about personal knowledge of 21 speed, 24 speed, 27 speed difference.
First look at the parameters.
21-speed gear plate 48-38-28 flywheel 14~28
24-speed disc 42-32-22 flywheel 11~30 (11~32)
27-speed disc 44-32-22 flywheel 11~30 (11~32)
The number of discs divided by the number of flywheels is the transmission ratio
21-speed maximum ratio 3.43, minimum ratio 1
24-speed maximum ratio 3.82, minimum ratio 0.73 (0.69)
27 speed max. ratio 4, min. ratio 0.73 (0.69)
The difference between the 27 and 24 speeds is that they have larger or smaller ratios than the 21 speeds, which allows you to run more and save more energy. The 24 speed car can reach 1.07 ratio even when using 2*1 ratio, if the flywheel is 11~32 car, it can reach 1 ratio, (the minimum ratio of 21 speed is 1). So 24 speed than 21 speed car advantage is not only in the fastest gear, but more in the slowest gear, so that you can take the mountain road more easily and more powerful. And the average novice just want 24 speed than 21 speed pedal faster, may be few people divide each gear plate and flywheel teeth once to see what the difference.
The 27-speed bike, its flywheel is generally the same as the 24-speed, the difference is only the largest front gear plate adjusted from 42 to 44, so that the nine speed ratios under the large gear plate are larger than the 24-speed, suitable for people with good physical strength. Another 24 speed or 27 speed with its different gears, the bike's various accessories are upgraded to a better model, which is also different.
Also, the small wheel folding car is not suitable for running mountain roads, it is only suitable for the better road conditions. Small-wheeled car is not slow, but in the mountain roads or do not run, not very safe, encounter poor road conditions or emergency braking is easy to fall.