Each bicycle type has a specific focus. What makes a triathlon bike different from a typical road bike is that the geometry and the design is made for flat, fast, straight, fast riding. The tri bike frame geometry sets the rider at a much steeper seat tube angle (typically in the range 75 to 81°) so he or she is more aerodynamic, while maintaining a proper torso, hip, and leg relationship for effective pedaling. The tri-specific (or time trial) geometry is the most comfortable, aerodynamic and efficient position for long timed races since the rider’s upper body is low, but the weight is supported by elbows that are resting on cushioned pads.
On a road bike, the upper body is propped up by your shoulders, which are held up by the back, arms, and hands. A road bike is more manoeuvrable than a tri bike due the rider’s centre of gravity being further back. Also, the road bike geometry is more upright. It is easier to see where you are going, you have more options for hand positions, better pelvic weight distribution, more natural breathing, less potential for strain below the neck, and it is much more comfortable on hilly courses.
So, do you need a tri bike to do a triathlon? No! Any road bike can be used and there are often more road bikes entered in the average triathlon event than there are tri or time trial specific bikes.
Which one should you choose? Here are some questions to ask yourself:
- Do you want to race triathlons competitively, does every second count? – Tri bike
- Are you going to do long-distance triathlons for more than a year? – Tri bike
- Are you new to cycling? – Road bike
- Commuting, touring, doing century or group rides? – Road bike
- Plan to do local club rides or road racing? – Road bike
- Riding on hilly terrain? – Road bike
It should be noted that putting aero bars on a conventional road bike does NOT make it a tri bike! Improperly fitted aero bars on a road bike are more likely to make you less aerodynamic, less powerful, and SLOWER! If simply mounted atop existing road bars, they will make you less aerodynamic, and because they stretch you out and compress your hip angle, the result is less comfort, much less efficient breathing (and in longer events, difficulty digesting!), lower power output, and worst of all, this can lead to severe lower back pain.
However, there is a proper way to fit aero bars to a road bike. It can be done effectively, but there is much more to it than simply slapping an aerobar and pads on top of a road handlebar. There are also a few road bikes on the market today that are actually designed to accommodate tri aero bars effectively.