Often, the answer is simply, "Why not?".
I suppose that's the only way to explain this new bike from a trio of French cyclists and inventors including professional rider Johan Le Bon (of the FDJ team): The Trocadero Fixie.
|In this still-frame from the video, you can get a pretty good look|
at the frame -- notice that it has very little triangulation behind
the head-tube -- which means it would probably give a fair bit
of flex even when it's NOT intentional.
Purely for the sake of unintentional (and juvenile) humor, I suggest visiting the Trocadero website, which is only available in French, then have it translated to English using Google Translate. Some highlights:
"The bike seems almost to dismember before our eyes." (Ewww!) "In question ? its frame is not fixed. Both sides of the vehicle can then rotate integrally in one way or another."
"An unusual and entertaining bike launched by three young Britons who has the gift to challenge! Its uniqueness, it detonates! Thrills guaranteed!"
It detonates? Somebody call the bomb squad. But it would definitely be thrilling.
"An approach that recalls the invention of the ATV. Initially, it was only tinkering and a lighted sports. Today it has become an Olympic sport, where the French excellent."
OK - so is the Trocadero "Fixie" a truly original idea? Maybe not exactly. Anybody out there remember the Swing Bike from the '70s? It was kind of like a Schwinn Sting-Ray type of bike, but the rear wheel (and drivetrain) of the bike could pivot on a fork much like the front. Little Jimmy Osmond used to appear in their ads. If one could master the technique, it was supposed to be very maneuverable, and capable of some pretty cool tricks - or the pivot could be locked out, and it would ride like any normal banana seat "muscle bike" of the era.
You can watch the Trocadero Fixie video right here: