Science of the Outdoors: Internal Gear Hub

This high-tech solution to cycling gears delivers easy shifting plus low maintenance for your bike commute, as our infographic explains.Internal Gear Hub

An internal-gear hub is a gear-ratio changing system that contains gears and lubricants sealed within the hub shell. This is an alternative to common derailleur gears, where the gears are exposed to the elements.

Internal-gear hubs are usually easier to maintain than derailleur gears. They also allow cyclists to change gears while stopped, which can be convenient for bike commuting.