The Lowdown on Time Trial Bike Frames
A time trial bike frame, or TT for short, is built to go fast. In most triathlons and all time trial races, the cyclist is not allowed to draft, and therefore the need to become as aerodynamic as possible is paramount. The front forks are very flat, which helps the TT bike to slice through the air, and the vertical down tube is normally shaped to the rear wheel and just a fraction from the tyre, again all to make this as aerodynamic as possible.
Time trial or TT bike frames are normally made from one of three different materials. They are:
The pros are that steel frames are relatively inexpensive, strong and easy to work with. The con is that it is quite heavy, making it less competitive for those seriously into their triathlons or time trial riding.
The beauty of carbon is that it can be shaped into almost any form and is super lightweight yet strong. These features are in part why carbon is one of the more expensive option in terms of materials.
Compared to steel frames, alloy frames have a lower density and strength however, they do have a better strength-to-weight ratio, which makes them the usual preferred option over steel frames.