As a coach, I often get asked if racing on a tri bike is an absolute must or if a road bike (even for long course) will be comparably effective. The short answer is: it depends. It depends on who is asking and why. It depends on one’s budget (not to mention bike storage capacity). It depends on an athlete’s physiology and history of injury. It depends on flexibility, on the course, on the distance, on experience level, on an infinite number of considerations. To be sure, a strong rider properly set up on a TT bike riding a flat course into the wind will be faster than if riding the same course in the same conditions on a road bike with an equally optimal bike fit. In reality, however, the comparison is rarely so straightforward. Multiple factors come into play when deciding whether to race on a tri or a road bike.
What IS the difference between a road bike and a TT bike?
To some, triathlon bikes (commonly referred to as TT bikes) look too intense to even contemplate riding. The primary difference between the two is in the geometry of the frame. Specifically, the seat tube angle on a TT bike is significantly larger than on a road bike. At 76 to 78 degrees, the TT bike permits a much more aero position (for the frame and the rider), versus the tighter seat tube angle of a road bike at (on average) 72 degrees. Built for going fast in a straight line, TT bikes are not ideal for cornering (they tend to be stiffer and less compliant than a road bike, and the aero bars and headtube angle make cornering less smooth than on a road bike). For these reasons, a TT bike can be less efficient on a technical course than a road bike. Additionally, TT bikes are heavier than road bikes so even beyond the issue of handling; they’re not ideal for climbing.
Most triathlon courses, however, do have substantial sections on which the advantages of a TT bike will be felt. Not only does the TT bike allow riders to get lower out of the wind while riding, but in being so, athletes can save precious energy for running hard off the bike. This will only be the case, however, if the rider can handle such an aggressive position. If the position is prohibitively uncomfortable, then riding hard will be impossible and the aerodynamic advantage won’t matter. I always insist that comfort trumps everything. One needs to be able to access one’s power for an effective ride, whether that be on road or TT bike.
Baring financial restrictions, bike-storage limitations, and any other mitigating factors, it would be ideal to have one of each. However, when a choice must be made, I tell athletes to consider what distances, race courses, even disciplines they plan on doing in making that choice. More often than not, I will advise a road bike over a TT bike so there are more options (including weekend group rides that tend to dissuade the use of TT bikes). There is always the possibility of affixing short, clip-on aero bars to a road bike and/or getting a pair of slick race wheels to speed up your ride. If racing shorter distances (sprint and Olympic) exclusively, particularly if the courses are hilly or technical, then riding a road bike even if you have a TT bike might be the most efficacious. However, if you know you won’t be doing group rides and are focusing on long course, in particular, then getting a TT bike is the way to go. Getting a UCI legal set up will enable you to jump in a few TTs as well.
No matter what you decide as you enter or exit the 2019 triathlon season, be certain to get a proper and comprehensive bike fit. Revisiting your bike fit every few years as your strength and flexibility changes is also important. Averaging about $300 a pop, they aren’t cheap, but a proper bike fit is worth every penny no matter what bike you ride.