In many countries, the bicycle was supplanted by motorized vehicles as the preferred mode of transportation by the early 20th century. However, the mountain bike, introduced in the 1970s with rugged features meant to increase durability and improve performance in rough terrain, has done much to renew interest in cycling. Today, mountain biking is recognized as a sport in its own right and has a vast community of enthusiasts that spans the globe. When did mountain biking debut at the Olympics? Discuss