With this years Tour incorporating nearly 100km’s against the clock, the GC contenders time trial bikes are going to play a massive roll in the overall classification of the 2012 Tour de France.

While stiffness and handling come into play, as does weight – but only to the point of it ‘not being too’ heavy, minimising the amount of air displaced is the be all and end all for racing against the clock. A small frontal surface area is one key area TT bike designers look at and many of the best bikes are super narrow when viewed from the front. It is never that simple however as wind from the side also has a huge impact. A good time trial bike will manage airflow over elaborately shaped surfaces to reduce turbulent airflow at any point on the frame. Directing this air across moving wheel surfaces and through gaps is also coming into play more as aerodynamicists gain more knowledge in the bike-designing arena.

Pic 1:

Smoothing airflow between component parts is a key element on modern TT bikes. The stem flows flawlessly into the top tube of the latest generation Canyon machine.

Pic 1: Stem and top tube intergration smooths air

Pic 2:

Disc wheels are almost mandatory for the modern time trial but up front, riders and mechanics will decide on mid or deep section wheels depending on the wind conditions. Some teams also have access to tri and four spoke wheels that some riders prefer. Getting wheels and frames to ‘merge’ has become more prevalent of late
and the Cannonade Slice TBC uses this clever channel to manage the
transition between moving and stationary components.

Pic 2: Front wheel choice depends on the course and the wind

Pic 3:

Component integration is becoming more common on TT bikes. The Canyon used by Katusha has an integrated front brake, totally shielded from the wind.

Pic 3: Canyon’s hidden front brake caliper

Trek’s Speed Concept 9 represents the state of the art

Cannondale Slice channels air over the rear wheel