Bicycles are very popular in many countries. many people use bicycles for exercise. but exercise is only one of the reason why bicycles are popular. another reason is money. bicycles are not expensive to buy. they do not need gas to make them go. they also are easy and cheap to fix. in cities, many people like bicycles better than cars. with a bicycle, they never have to wait in traffic. they also di not have to find a place to park. and finally, bicycles do not cause any pollution!