Many people will be confronted with this important question when they start triathlon: Should I buy a road bike or a triathlon bike?
In my opinion, the answer to this is very easy: If you are in any doubt, opt for a road bike! I will now explain why the answer to this is so clear-cut.
A road bike is more convenient, easy to steer (it is more stable and offers better braking), it is more lightweight and easy to maintain.
A beginner in triathlon will have to start by getting used to pedalling over increasingly long distances. When ramping up from 20 km to 90 km distances, comfort is an essential factor.
Confidence is another crucial point. I know many people who started to be afraid of cycling because of a fall due to using clipless pedals. Having a more stable bike with better braking and the ability to keep your hands on the brakes at all times will help you overcome any fears.
I know all the arguments of those who prefer triathlon bikes: they are more aerodynamic, more rigid, etc.
The aerodynamic difference between a good road bike and a triathlon bike is the same as that between a road cycling helmet and a triathlon helmet: it does have an effect but it is not the most important factor. What's more, for a beginner, the rigidity of a triathlon bike will not be the most important factor because the cyclist will never attain the level of watts needed to bend the frame and cause a drop in power output.
Another important point is that 80% of the aerodynamic drag comes from the cyclist himself whereas only 20% of the drag comes from the bike and the wheels. We can therefore say that the most important factor is not the bike but the position adopted by the cyclist on the bike. A triathlon bike helps you to adopt a more "aggressive" and aerodynamic cycling position. But the ability to maintain this position while pedalling very hard requires years of training, muscle strengthening and experience in bike handling. Most beginners who use a triathlon bike adopt a less aggressive cycling position, that is equivalent to the position they would adopt on a road bike equipped with aero bars.
What's more, do not imagine that you will only need a road bike for one year and you will need to replace it with a triathlon bike in the following year. A road bike that has been customised with certain strategic components specifically designed for triathlon will last much longer than one year. In my case, I took part in the Ironman 70.3 world championships with an optimised road bike and I can tell you that the limiting factor was the cyclist, not the bike!
Moreover, with a road bike, you can enjoy the route and exceptional scenery more without being scared in the downhill sections!
So, no doubt you will want to know why triathlon bikes exist?
In my opinion, they exist because it is a fact that 20% of aerodynamic drag comes from the bike and the more aggressive riding positions can only be achieved on a triathlon bike. These two factors are less important for most sportsmen and women, but they can clearly make a difference at a world championship event. It's up to each individual to analyse the factors that are preventing them from wiping off the minutes they still need to achieve their target.