The Sunstar iBike S03+ is the only fully integrated electric crank drive system with a torque sensor. Although the batteries are made in Germany, the concept and main motor unit have been evolving in Japan for over 10 years. The iBike system works just like the Panasonic, Bosch, Yamaha, Shimano Steps, and Kalkhoff Impulse crank drive systems, but it is the only system that can be retrofitted to your own choice of bike.

  • Example
  • Example

The main benefits of the system:

  • Japanese design and German manufacturing underpin the last decade of the Sunstar’s development, so you can be assured of its quality and reliability.
  • The system fits any standard bottom bracket, and keeps its weight low and inconspicuous.
  • It makes use of the bike’s gears to improve efficiency and maintain natural cycling dynamics. This is an advantage over hub-driven electric bikes.
  • It’s a clever set up that senses torque pressure on pedals, cadence, and the bike’s speed in order to seamlessly adjust to different riding styles.
  • The weight of the complete system starts at under 4Kg.
  • The range can be in excess of 60 miles.
  • It is easy to de-restrict the system for off-road riding.
  • There is a 2-year warranty on parts, including the battery.


Key Performance Specifications:

  • Average Range:  20 – 60miles depending on battery option, terrain, and assist level
  • Hill Climbing Torque (Nm):  50 Nm at the wheel
  • Max Power:  480W
  • Nominal Power:  250W
  • Available as a 24V or 36V system
  • Max Motor Speed:  15mph with speed sensor fitted, 25mph without (not legal on UK roads)
  • Battery Warranty:  2 Year
  • Battery weight: 1 to 3Kg
  • Battery capacities:  2.5Ah, 11Ah, 16Ah
  • Rider Controls:  LED or LCD interface
  • Average charge time:  2-4 hours

The Sunstar SO3+ receives glowing reviews all over the internet, but this review from bikeradar does a professional job of weighing up the pros and cons of the system.

For more details see Sunstar – Motor Pricing and Configuration Options