When you want to turn yourself into a road-dominating, pedaling missile, you want a triathlon bike. Tri’ bikes are designed to reduce aerodynamic drag. They do this by sculpting the vehicle first to hide from the wind as much as possible, and then putting the rider in a slippery position, reducing frontal area to the minimum, thanks to a forward position and triathlon handlebars.
Wheels are an essential part of the wind-cheating equation. The deeper the rim depth the easier it is to pedal the bike at speed (and the trickier to pilot in crosswinds). Some come with shallow aluminum rims, others with deep carbon-fiber rims. Aluminum are typically seen as training wheels that can be raced, carbon as race wheels that can be trained on. There are three flavors of rim: clincher, tubeless, and tubular. Tubulars are usually seen as “race only.” Clinchers and tubeless can be both raced and trained. Clinchers have a tube inside, while tubeless do not, but tubeless can be run tubed, though not the other way around.
The Pro’s Closet has a deep collection of used triathlon and tt bikes for sale, everything from beginner triathlon bikes to full-on Ironman winning bikes. One of the great things about special-purpose rides is that they often treated well by their stewards. That is to write most of the previous owners of these bikes have other bikes as well and probably spent more time on their road bikes outdoors than on their tri’ bikes. As a result, these bikes probably haven’t seen much in the way of bad weather. Tri’ bikes are rarely out in winter months and rarely crashed.
The best triathlon bikes don’t take a single shape. Sometimes they’re relatively traditional, like Trek and Specialized triathlon bikes. Sometimes they’re radical, like Ventum bikes. Quintana Roo and Cervélo largely try to split the difference. Cervélo’s P-Series, including the P2 and P3 mix radical shaping with a double-diamond design.
There might be some confusion in names. Not all triathlon bikes are time trial bikes and not all time trial bikes are tri’ bikes. While they look really similar and are usually interchangeable, there are some design constraints put on international-level time trial bike races. If you are not racing a national championship or internationally-sanctioned Junior, U23, or Elite race, you probably don’t need to have your bike conform to the UCI design standards of a time trial bike, but you probably should remove the wind-cheating storage boxes and bags if your bike comes with them.