Time Trial Frames & Triathlon Frames
Time trial bikes are essentially a road bike but with the emphasis being on aerodynamics. They are primarily designed for going as fast as possible on a reasonably flat road in a reasonably straight line, the seat angles are steeper to enable the rider to get lower at the handlebars to create a more aerodynamic profile, weight is not as much of an issue as it is usually used for pretty flat roads. Most of the tube sections of the frame where possible are of an 
aerodynamic profile as is the seat post, handlebars and wheels.
The handlebars are usually upturned cowhorn style bars, now more often than not made from carbon fibre these usually incorporate the tri-bars, which enable the rider to be in a comfortable and aerodynamic position. Gear lever are usually fitted to the end of the tri-bars to allow the rider to maintain the aero position qhilst changing gear.
Time trial wheels are usually deep rimmed to create an aerodynamic profile but also create a much more vertically rigid rim which allows fewer spokes to be used further enhancing the aerodynamics, even the spokes themselves have an aerodynamic profile, for ultimate aerodynamics a disc wheel is often ised in the rear to create a less turbulent airflow.
