The toothed wheel or gear [1] - Main gear part as a disk with teeth on a cylindrical or a conical surface entering into engagement with the teeth of the other gear. In mechanical engineering it made small gear called pinion and large - wheel. Often, however, all the gears referred gears. The minimum number of sprocket teeth is limited due to deterioration of joints, the velocity unevenness and noise during operation. For transmission bush roller chains 12 it is administered (for gear ratios and 6) to 31 (for 1), for transmissions with toothed chains - from 17 to 40 at the same gear ratios. Otherwise, there will be the following condition is smooth and reliable engagement. Hence the name - gear. -link removed-