If you're used to the classic geometries of steel road frames a la "Breaking Away," today's race machines may look very strange to you indeed. Massive down tubes, huge bottom bracket areas, and fluid shapes mimicking today's automobile designs are all but the norm, all geared towards creating a platform that transfers the energy input from the rider as efficiently as possible to turning the wheels, made as light as possible.
Before cycling's governing body UCI created a stringent set of rules in the hopes of leveling the field in terms of performance advantages afforded to the cyclist by his or her machine, many companies, especially and most visibly frame builders were experimenting with designs that would make the hallmark innovations of today's bikes seem tame. Fairings, funny bikes, frames with no triangles were all tried in an attempt to make the most aerodynamic time trial bike possible. Aerodynamics are especially important in a TT as there is no peloton or other riders to share the job of pulling at the front, the rider must fight the wind on his or her own and race against the clock.
Recently on the NYCfixed forum, Ethan Laek discovered a treasure trove of some of Bianchi's TT bikes from before UCI sanctions limited the designs to the types of bikes we see in the TT today. Check him out over at Laek House when you get a chance and support a local NYC/BK business. He does some really cool stuff, most notably applications of ELVS which you can grab on some Velocity Deep-Vs.
So, just for comparison, here is Bianchi's 2010 Team Flaminia TT bike, the Pico Chrono.
And here are some of the pre-UCI sanction Bianchi designs... wild stuff!
One of Pantani's TT bikes
This one is CRAZY...
Note the bottom bracket shell, which is apparently integrated into the downtube, and also the DISC brakes!? and the aero bar extensions from the fork, too.
Here's a quick comparison of Pantani's bike from earlier in the decade (2002?) with a 2010 Flaminia 928 SL.
Pretty wild, no? Cycling is continually progressing as companies try to innovate and push the limits of design while following the rules (for the most part...), and that makes it such an appealing, exciting sport to follow. The fact that there is a market for equipment that facilitates maximizing human performance simultaneously existing with a market for established technology that will allow for a fun ride makes cycling accessible to a vast spectrum of demographics. Fun stuff!