There are a few differences between a road bike and triathlon bike. Before making a decision on whether to buy a road bike or triathlon bike, keep individual needs in mind. You decision should be based on the sport in which you participate, your size, including height and weight, and your level of fitness.
The road bike is made for different courses. It can handle inclines, curves and close-quarters riding. The seat position makes it easier for the rider to increase pedaling power. The triathlon bike is usually meant to go faster over shorter distances, since riding in triathlons accounts for only one-third of the competition.
Triathlon bikes are more aerodynamic than road bikes. The center tube is often more rounded down to let the air flow past. Triathlon tubes are more steeply angled to aid in the aerodynamics of the bike. The aerodynamic improvement will help save your quadriceps for the latter portions of the race.
With diversity comes durability. Your road bike is more likely to survive a crash than a triathlon bike. Add in the aerodynamic nature of the triathlon bike being thinner than the road bike and you’re more likely to have a bike after a wreck. That said, if you crash in a race of any caliber it is unlikely you will win, but you still want to have a chance and the road bike is more likely to stand up to a mishap.
Triathlon bikes tend to be angled down further to improve upon the aerodynamics. The seats are higher and the handlebars are lower than those on road bikes. Added handlebar attachments can make the angle steeper and allow for a faster time when the rider has the right kind of helmet.
Depending on the brand of the bike, the two tend to be about even. The additions that cost more on a road bike will cost about the same on the triathlon bike. Take into account the kinds of parts you want on your bike. Carbon fiber frames will cost more than aluminum or steel. They will also be lighter, which can be a benefit during a race.