Joule 3 Dynamo Comp Front Wheel for 20" Tern Bikes


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

The Comp rim set uses best-in-class components to create a whole that sets a new standard in dynamo wheels. It features butted spokes and double-walled rims to create a light, yet strong and rigid wheel. Each wheel is individually hand-laced and trued.

With the Joule 3, you’ll never again worry about batteries for your evening rides – green power is always on tap when you need it.

For 20″ wheel bicycles with V-brakes. Compatible with standard dynamo hub powered lights such as the Tern Valo 2. Available in silver and black.


  • OLD: 74 mm
  • No. spoke holes: 20
  • Output: 6V, 3W (German StVZO compliant)
  • Weight: 1.9 lb (853 g) w/o skewer
  • Suitable tire widths: 0.8″ (20 mm) — 1.35″ (35 mm) 


  • Joule 3 Dynamo Hub in 20″ Comp rim set
  • Quick-release skewer
  • Cable connector
  • Product manual

Tire and inner tube not included.

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