One of the biggest questions that new triathletes and cyclists have is whether to buy a triathlon bike or a standard road bike. To answer this question, one must first understand the differences between the two. In essence, a triathlon bike is designed to be more comfortable when ridden in an aerodynamic position using aero bars. This means that the weight of the body is resting on the forearms, which are stretched out towards the middle of the handlebars. A road bike, on the other hand, is designed to be ridden with the arms out to the sides, supporting the weight of the body.
These differences between the two bikes can be attributed to subtle variations in the geometry of the frame. A triathlon bike has a shorter top bar and a shallower seat angle, making the rider feel like he or she is sitting slightly lower and further back. The front section of the frame is elongated, which gives the rider room to stretch the upper body out towards the aero bars. A road bike has a longer top bar and more sharply angled seat, which gives the rider more room to move his or her legs freely. The shorter front section of a road bike allows a rider to support his or her body weight without having to lean into the handlebars.
The variations in frame design between the two help improve performance in different ways. The geometry of a triathlon bike helps to naturally support the weight of the upper body, without using up the rider's strength. In addition, the stretched-out back position attributed to the bike's shape helps keep the back flexible and reduces cramps, which allows the rider to transition more quickly into running. The increased leg space on a road bike prevents the thighs from getting too close to the chest or abdomen, allowing for improved breathing. This increased spacing also leads to less tension in the legs, which lets the rider cycle more quickly and for a longer period.
While these differences may seem subtle for the novice rider, there are situations where one type of bike can vastly outperform the other. A road bike is typically much better on hilly terrain, and also handles much better on tight corners or turns. The stretched out position using on a triathlon bike conserves energy, but also contributes to poor handling, making this bike a poor choice for group races or drafting situations. In conclusion, for those who plan to mainly take part in road races or group events, a road bike is a better choice. Those who plan to participate in triathlons or other multisport events should stick with a triathlon bike.