Triathlon is a rapidly growing pastime in the United States. As a result, the decision between purchasing a triathlon bike or road bike has become an increasingly common discussion among those interested in entering the sport.
In short, if you plan on participating in an Ironman or half Ironman event, then you should probably get a triathlon bike. This type of bike has a 76 to 78 degree seat tube angle that allows you to ride in an aerodynamic position and keeps your legs fresh for the run. Aerodynamics is advantageous for triathletes because unlike cycling, drafting is typically illegal. In a triathlon, you have to be at least three feet behind the person in front of you. This means you can’t feed off the energy of other riders, or take a break in the back of the pack. A tri-bike places your body in an aggressive position that reduces drag for the solo rider. This position not only reduces drag, but it also places less stress on your quads, possibly leaving you fresher for the run portion of the race.
So while this aggressive setup is great for triathletes, it presents a few problems for traditional road biking. First, triathlon bikes are like drag race cars, they were meant to go straight, flat, and fast. Consequently, the tri-bike performs poorly on hills. They are typically heavier than comparable road bikes, and the 78 degree seat tube angle is not an optimal position for climbing. On a road bike, you can lean back in your saddle, engage your hamstrings, and push on the pedals. The more aggressive seat tube angle on a tri-bike, however, puts you further over the bottom bracket and makes engaging anything but your quads and calves more difficult.
Aero Road Bike
The aero road bike is amenable to both road biking and short course triathlons. It has a traditional road bike seat tube angle at around 72 degrees. Because of this, it is a great handler and a proficient climber, so you can feel safe at your local group ride. The amazing thing is, that like a triathlon bike, the frame is built for aerodynamics. If you want to compete in a sprint, Olympic, or draft legal triathlon, attach a pair or ITU clip-on aero bars to your drop bars, put on an aero helmet, maybe some race wheels and you’re good to go. This is an exceptional set up for hillier triathlons like Rev 3 Knoxville.
Many people are not in the market for both a triathlon and a road bike. So if you want to race half-Ironman to Ironman distance events, then you should probably get a tri-bike. These events are long and you will spend a ton of time in the saddle, making aerodynamics and efficiency vital. The length of these events magnifies the benefits of a tri-bike and makes it worth the cost.
On the other hand, if group rides and cycling events are attractive to you, but you still want to do some sprint and / or Olympic distance triathlons, then go for an aero road bike. These bikes convert amazingly into aerodynamic machines. The downsides? The set up is not as aero as a tri-bike and your legs may not be as fresh on the run. But remember, you are not spending as much time in the saddle in a sprint or Olympic triathlon so the costs are minimized. It’s a relatively small price to pay to be able to enjoy group rides, the option for a comfortable upright position, great handling, and possibly a lighter bike.