Joule 3 Dynamo Pro Front Wheel for 20" Tern Bikes


The BioLogic 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 Pro rim set uses best-in-class components to create a whole that sets a new standard in dynamo wheels. It features patented Rolf paired-spoke technology: 14 custom-forged, double-butted Sapim spokes, tensioned to double the industry standard, Sapim Polyax internal nipples, results in the bike industry’s lightest dynamo hub wheel. Each wheel is individually hand-laced and trued and the meticulous build process includes two rounds of spoke de-stressing on custom machinery and three rounds of hand-trueing.

With the BioLogic Joule 3 Pro wheels, 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. Available in silver and black.


  • OLD: 74 mm
  • No. spoke holes: 14
  • Output: 6V, 3W (German StVZO compliant)
  • Weight: 1.59 lb (722 g) w/o skewer
  • Suitable tire widths: 0.8″ (20 mm)  — 1.35″ (35 mm) 


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

Tire and inner tube not included.

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