The bike uses NuVinci technology to create a gear system unlike anything else. Instead of shifting back and forth between numbered gears you can adjust it smoothly by whatever increment you want without worrying about clicking into gears. You can even switch gears while standing still. The bike's mechanics are also all internal so repairs are rarely necessary.
A basic gear system works by shifting the bike's chain, which connects the pedals to the wheels, between metal cogs of different sizes. A higher gear makes it harder to pedal but each rotation creates more movement. A lower gear does the opposite: easier to pedal but less movement.
It turns out, however, that Leonardo da Vinci invented an alternative method way back in 1490. Unfortunately, his designs for a stepless, continually variable transmission were never completed. 500 years later Donald Miller uncovered da Vinci's sketches and began to tinker with the idea. He eventually created a continuously variable transmission (CVT) that would work for a bicycle, and called his invention the NuVinci.
The first bike to use this new gear technology, the Ellsworth Ride, cost a whopping $3000. The latest model of the NuVinci is lighter, making it easier to mount on a bike. The result is the Novara Gotham by Rei which features both the NuVinci N360 hub and a Gates belt drive for just $1299.
PopSci took the Novara out for a test drive and came away describing a positive but bizarre experience.
The first thing you notice about the NuVinci in action is...well, nothing. Gliding along in near silence (it's a lot quieter than a traditional internally geared hub), you twist the grip shifter to make things easier or harder, and that's all there is to it.
The author argues the the absence of the typical clicking sound that comes with shifting gears creates a disconnect between the rider and the bicycle. However, the tradeoff may be worth it. The Novara's chain is grease-free which means no more stains on your pants or legs, and it will never rust. According to the manufacturer the chain's lifespan is twice that of a regular one.
How it works: