Joule™ 3 Pro Rim Set

The Joule 3 dynamo hub 20” rim set lets you generate electricity to power your lights or charge devices on your bike while riding. The Joule 3, winner of a 2012 Eurobike Award, is one of the lightest, most efficient bicycle dynamo hubs on the market, which means more power generated at a given speed. The patented magnet configuration yields barely noticeable drag while a polished, laser etched, and precision-machined flange pattern present high performance in a beautiful, small package.

The Pro rim set features custom Sapim Laser double-butted spokes from Belgium and is assembled and trued by hand. The spokes on a typical rim set are de-stressed only once. The Pro rim set is de-stressed three times so it runs truer for a longer time. Patented Rolf paired-spoke technology allows the use of only 14 spokes, making it very light yet stiff and strong. A double-walled rim provides extra stiffness and strength and a CNCed braking surface offers excellent stopping power.

Fits 20”-wheel bikes with V-brakes and a 74 mm OLD. Works with standard dynamo hub powered lights. Available in silver and black.

  • 73% generator efficiency — one of the most efficient
  • One of the lowest drag of all available dynamo hubs
  • Built and trued by hand
  • Custom Sapim Laser double-butted spokes from Belgium
  • Double-walled rims for stiffness and strength
  • German StVZO compliant (3W, 6V)
  • Fits 20” bicycles with 74 mm OLD
  • Weighs only 722 g (w/o skewer)