Two wheels good, three wheels better? That's the theory behind the Kiffy Urban Tricycle, which is designed with just about everything you want to do in a city in mind. It's light, foldable, portable, maneuverable, and stable.

The work of Agence 360, a French design firm, the 28-pound Kiffy can be disassembled and transformed into a pushable hand cart for use in a grocery store. The 4-foot-9-inch-long bike folds down to take up just 2' by 2', so it's easily rolled into a subway car or an elevator. A clever front suspension system dubbed "Swing" allows the front of the tricycle to tilt like a regular bike, providing stability even on slopes. Front disc brakes keep everything under control.

The inventor, Norbert Peytour, says that cycling is a form of care-free travel, with no fuel levels to watch, little to no maintenance, no engine that can fail. He rejects "advances" like the electric bike, which add complexity (and fuel consumption) to the mix. The point of the Kiffy is "to conserve the carefreeness of the bicycle," while adding flexibility and practicality.

The aluminum-framed trike comes in two options, a two-speed "Flash" version that is foldable, or a single-speed "Fix" version that is slightly lighter. Pricing and availability of the Kiffy have not been announced, but we'll be keeping an eye out for this one.