Электровелосипеды с планетарной втулкой

Planetary hub

— a closed gear shifting mechanism built into the rear wheel hub. Unlike a conventional system with an external shifter and cassette, the gears are hidden inside the housing, providing better protection from dirt, water, and impacts. This option is convenient for city e-bikes, daily commutes, and leisurely rides, but it usually has a smaller range of gears and is more difficult to repair than a traditional external transmission.