Hub gears

device for changing gear ratio on bikes

thumb|A Sturmey-Archer three speed hub, the most common kind of Sturmey-Archer gear Sturmey-Archer was a manufacturing company originally from Nottingham, England. It primarily produced bicycle hub gears, brakes and a great many other sundry bicycle components, most prominently during its heyday as a subsidiary of the Raleigh Bicycle Company. Earlier, it had also manufactured motorcycle hubs, gearboxes and engines.

thumb|Internal Schematic of a Rohloff Speedhub 500/14 Rohloff AG is a German company from Fuldatal near Kassel that manufactures hub gears, bicycle chains and tools that are known for their durability and high performance. The company's logo is a black silhouette of a raven on a yellow background.

internal hub gear for bicycles

roller-based continuously variable transmission