I still don't see any good argument for using TT bikes in a stage race. If the point of the TT bike is that it is more aero and allows a more aero position for the rider, and everyone is allowed to use them...then what is the point? Have a time trial on road bikes and Cancellara is still going to be in the top three on any given day; Evans is still going to beat Schleck. So what is gained by introducing TT bikes into the equation? Bragging rights for the highest top speed that is imperceptible unless you're standing on the side of the road as the rider passes by?
What we often see is certain teams and riders humiliating themselves with out-of-control crashes and other mishaps. How does that serve the sport well? On road bikes or TT bikes, Wiggins is still going to beat Cavendish in a long race against the clock—every time. So...what is the point?
Not to mention, allowing TT bikes means that the bike usually dictates the course—which is usually bland and boring beyond words. One beautiful exception to this was the Stage 12 TT for the 2009 Giro. That presented the rare instance where,
because of the course, most (all?) riders opted for road bikes, many with clip-on aero bars attached.
I would love to see future TTs on more varied terrain, on road bikes, that put more of the rider's overall skills to the test. Call me crazy.