Answer:
Gear ratio = 3.75
Step-by-step explanation:
A chain drive is an efficient technique used for the transmission of mechanical power from one point to another. For example, it is used for transmitting power to the wheels of a bicycle, motorcycle, motor vehicle and other machineries such as chain saw etc.
Chain drive (gear) ratio is the ratio between the rotational speeds of the input and output sprockets of a roller chain drive system. This ultimately implies that, chain drive (gear) ratio is the ratio of the number of teeth on the driving sprocket (T1) divided to the number of teeth on the driven sprocket (T2).
Also, the chain drive (gear) ratio can be calculated by dividing the number of teeth on the large sprocket by the number of teeth on the small sprocket.
Given the following data;
Number of teeth of the driver sprocket, T1 = 75
Number of teeth of the driven sprocket, T2 = 20
Gear ratio = T1/T2
Gear ratio = 75/20
Gear ratio = 3.75