Clipless road pedals have been around for decades, but just how easy are they to use? Clipping back in at every stoplight can be a pain. Speedplay "flipped the script" and put the binding elements in the cleats, rather than the pedals.
Richard Bryne -the inventor of Speedplay pedals- looked at how clipless pedals could be made easier to use, as well as making them light and adjustable. Cleat "float" (the ability of the cleat and the shoe to move slightly while still engaged in the pedal) has been determined to be beneficial for nearly all riders looking to improve comfort and resist injury. The Speedplay Zero pedal has an adjustable float on the cleat, allowing the rider to change the inboard and outboard float independantly. Multiple cleats are not needed to change the pedal's float to match the rider's fit needs. The pedal is double-sided, making every pedal engagement easier at every stoplight and stop sign. The stainless steel "bowties" on the pedal body are what holds the cleat on the pedal, not chunks of plastic. You don't have to crank down on a tension adjustment screw to stay in the pedals during a hard effort like sprinting and climbing. Cornering clearance is very high: 37 degrees! In comparison, old-style LOOK pedals from the 80's were around 29-30 degrees. Stack height for Speedplay Zero Stainless pedals are a mere 11.5mm, allowing the rider to feel more connected to the bike.
Installing the cleats onto road shoes may require shims (included) to match the curve of a shoe sole. A printed guide for shoe/cleat installation and compatibility comes with every pair of pedals. Nearly all 3-bolt bolt pattern shoes will work. 4-bolt Speedplay-specific shoes are, of course, much better for installation and even lower stack height, but require a stainless steel wear plate (sold separately) to be installed under the cleats.
What more needs to be said? How about wins at the Tour de France, Giro d'Italia, Paris-Roubaix, Amstel Gold, Paris-Nice, World Time Trial Championship, Hawaii Ironman World Championships, and the countless other races that have been won by champions using Zero pedals.