Shimano
Di2 Cockpit Junction Box 5-Port
Best central hub for cyclists upgrading to complex electronic shifting setups.
Elevate your cycling experience with the Shimano Di2 Cockpit Junction Box. This essential 5-port unit acts as the central hub for your electronic shifting system, ensuring seamless communication between shifters, derailleurs, and the battery. It's engineered to deliver precise and reliable gear changes, contributing to a clean cockpit aesthetic and the overall performance of your Di2 drivetrain. Integrate this vital component for a smooth, connected, and efficient ride, enhancing your connection to the road.
$154.99
Owner Satisfaction
4.5
/ 5
Category Rank
671
/ 2109
#671 in Components
Price vs Category Average
+51%
Above average
Model Number
90
/ ISMEWB
Who it's for
- Mechanics seeking a tidy and organized cable management solution
- Cyclists needing easy access to battery charging and system diagnostics
- Aero-focused riders wanting a streamlined and minimalist cockpit profile
Who should skip it
- Builders looking to minimize extra hardware and installation complexity
- Owners of modern 12-speed wireless electronic shifting systems
- Off-road riders concerned about potential impact or moisture damage
Performance breakdown
System Connectivity
Five ports provide unmatched flexibility for complex electronic drivetrain configurations.
Signal Reliability
Hardwired connections ensure zero latency during critical gear shifts.
Cockpit Integration
Low-profile design keeps your handlebars looking clean and professional.
Installation Ease
Straightforward plug-and-play setup simplifies the Di2 wiring process.
Build Durability
Robust housing protects sensitive electronics from road vibration and moisture.
Diagnostic Feedback
Integrated LED indicators make battery and system status checks effortless.
Key Specs
Model Number
ISMEW90B
Port Count
5
Brand
Shimano
Category
Components
Features
- Central hub for Di2 electronic shifting
- Manages system communication efficiently
- Enables precise electronic gear changes
- Clean cockpit integration
- Crucial for system reliability
- 5-port connectivity
What customers say
The Shimano Di2 Cockpit Junction Box 5-Port is universally praised as a highly reliable and indispensable component of the Di2 ecosystem. Users value its flawless functionality, which ensures the crisp, consistent shifting Di2 is known for. The five port configuration offers excellent flexibility for riders needing extra connections for satellite or sprint shifters. While system setup can be complex, the junction box integrates cleanly, contributing to a sleek cockpit appearance. Customers confirm its robust construction inspires confidence in its longevity. Despite the premium price, the consensus is that this component is a worthwhile investment, solidifying its status as a top-tier, set it and forget it piece of engineering that significantly enhances the riding experience.
Know before you buy
The SM-EW90-B acts as the central communication hub for your electronic drivetrain. It connects your shifters, derailleurs, and battery, allowing the system to transmit signals for precise gear changes.
The 5-port version is designed for more complex setups, such as those using climbing shifters, sprint shifters, or time trial extensions. If you only have standard road shifters, the 3-port model is likely sufficient.
This unit is designed to mount under your stem, typically held in place by a rubber strap or a specialized mount. It keeps your cockpit tidy while remaining accessible for charging and system diagnostics.
Yes, it features a built-in charging port. You can plug your Shimano Di2 charger directly into this unit to charge the internal battery without needing to remove any components.
It is compatible with most E-tube Di2 systems, but it is specifically intended for wired configurations. Always verify your specific derailleur and shifter generation to ensure full compatibility with the E-tube platform.
Still have a question?
Ask Hayley anything about this product before you decide.