Learning the difference between a road bike and a triathlon bike will help you decide which bike suits your needs. Designed for efficient riding on pavement or pavement-like surfaces, road bikes and triathlon bikes share many qualities, including their frame materials and basic composition. However, differences between the two bikes can be vast.
Road bike frames and components come in a variety of sizes and shapes, but most are round. Road bike frame designers often aim for overall performance. Triathlon bike frames are designed for shorter rides and seek to maximize efficiency through increased aerodynamics. Elongated frames, tubes and handlebars help reduce resistance and riders use the aero position for the same reason. Consequently, triathlon bike riders are able to finish the short courses in their events with quicker times.
Road bikes typically have a 73-degree seat tube, which requires a longer top tube and chain stays to balance the frame. Additionally, road bike frames have a more aggressive head angle, which is steeper. The steep head angle helps keep the bike's length within reason and gives a rider more aggressive steering capabilities for cornering. Road bike frames are designed to perform well in many conditions, including climbing, cornering and descending.
Triathlon bikes have steeper seat tubes, which create shorter top tubes. Consequently, frame builders use shorter chain stays to balance triathlon frames. The shorter rear frame requires a less steep head angle, resulting in slower steering to accommodate for the shorter rear of the bike. Triathlon bike frames are built to be niche performers, while giving the rider the right body position for triathlon racing.
Ideally, a road bike rider should sit upright, with the weight of his upper body stretched out over the brake hoods, while his upper body weight is dispersed over the frame to balance the ride. In this position, a rider uses all of his leg muscles and can endure longer rides.
Triathlon bike riders use a forward-leaning position, known as the aero position. Riders place the weight of their upper body on the elbows, which rest on aero bars over the front of the handlebars. Triathlon bikes allow the rider to remain comfortable for long periods, while primarily using their hamstrings. Riders can thus conserve their quadriceps for the running portion of the race.