General relationship between the number of teeth of the chain wheel and the number of links of the chain
The number of teeth and sections between sprockets and chains, as well as the power of the whole car and the gear ratio of each gear are carefully designed before leaving the factory, and matched by the best and parameters, and should not be changed. After the chain is stretched, the length of each section will be longer than the distance between the teeth of the sprocket, so if you take off a section, it will not mesh well with the sprocket and will "bite" the chain during the rotation, which will not only increase the sound, but also increase the wear and tear. The pitch between the new chain and the old sprocket can't match well, so the new chain will wear out quickly. In addition to the quality of the chain, improper adjustment of the chain also has a great influence on the chain's life. The relationship between the number of teeth of sprocket wheel and the number of knots of chain is that the relationship between the number of teeth of sprocket wheel and the number of knots of chain is that they are prime numbers. In other words, there is only a convention between them 1.
For example, the small wheel is 14, the big wheel is 45, and the chain is 118, so there is an advantage that no matter the big wheel or the small wheel, any one of their teeth will definitely have a chance to wedge into any section of the chain, so that the sprocket and the chain can achieve balanced wear, and will not cause a certain tooth or a certain section of the bias grinding phenomenon. It makes the sprocket run smoothly and harmoniously. If we set one tooth of the small wheel as A and the corresponding one as A1, and one tooth of the big wheel as B and the corresponding one as B1 when the sprocket is stationary, then the chain will take 630 turns to return to the state where A and A1, B and B1 are corresponding to such a number of teeth. At that time, the small wheel has already made 5310 revolutions. At that time, the small wheel has made 5310 revolutions, and each tooth of it has passed through each link 45 times, and the big wheel has made 1652 revolutions, and each tooth of it has passed through each link 14 times. After that it starts to repeat again.
If the small wheel is 15, the big wheel is 40, and the chain is 120, then each tooth in the small wheel can only pass through 8 fixed joints in the chain, and the other joints cannot be reached for the rest of its life. Each tooth of the big wheel can only pass through 3 fixed joints of the chain, and the other joints cannot be reached in a lifetime. The chain only turns once, and then it starts to repeat. Then the chain will have partial wear. It is easily damaged.
Of course, if the number of teeth of the two wheels will not be mutual, the problem is not big, the key is that the number of teeth and the number of chain links must be mutual