The Shimano Di2 MU-UR520 Motor Unit brings precise, cable-free electronic shifting to 5-speed internal gear hub e-bikes. Designed for city and trekking riders who want the reliability of Di2 technology paired with a Bosch drive system, this motor unit eliminates mechanical shift cables and delivers instantaneous, consistent gear changes every time.

Highlights

• Di2 electronic shifting: Instantaneous, smooth gear changes without mechanical cables — precise every time.
• Bosch drive unit integration: Connects to compatible Bosch BSE3 drive units via the EW-PS300 electric power supply wire.
• Belt and chain compatible: Maintains the same belt/chain line clearance as the MU-UR510, making it suitable for both belt and chain drivetrain setups.
• Wireless LED indicator: On-board LED indicator and function button provide clear visual feedback and easy rider control.
• E-TUBE PROJECT Cyclist App: Adjust motor unit settings and update firmware wirelessly via Bluetooth from your smartphone.
• Clean city bike build: Designed for urban and trekking e-bikes where a tidy, low-maintenance drivetrain is a priority.

E-TUBE PROJECT Integration

The MU-UR520 is fully compatible with Shimano's E-TUBE PROJECT Cyclist app, allowing you to customise shifting behaviour, check system status, and keep firmware up to date — all from your smartphone over Bluetooth LE. The on-board SD300 port also supports direct firmware updates when required.

Compatibility & Fit

The MU-UR520 5-speed variant (IMUUR520CA) is compatible with the Shimano Nexus SG-C7050-5 internal gear hub. It connects to compatible Bosch BSE3 e-bike drive units using the EW-PS300 electric power supply wire (sold separately). Supports belt and chain drivetrains. For 8-speed or 11-speed applications, refer to the IMUUR520BA (8-speed) or IMUUR520AA (11-speed) variants.