That's why companies such as Superpedestrian, Evelo and Hycore have developed electric-assist wheels containing a battery pack and motor, that can simply be installed on a regular bike. Although most of them are still in the "pre-order" stage, FlyKly's Smart Wheel is now actually reaching consumers. I recently got to try one out, and it definitely does help with the hills ... although at least one tweak is still needed.

The specs

The Smart Wheel weighs 3 kg (6 lb), and its hub contains a lithium battery pack, a 250-watt motor, a Bluetooth module, and sensors for monitoring factors such as acceleration, torque and temperature. The battery takes three hours to charge from a regular outlet, and has a stated minimum range of about 40 km (25 miles).