Shimano
Di2 Cockpit Junction Box 3-Port
Best central hub for cyclists upgrading to electronic shifting systems.
The Shimano Di2 Cockpit Junction Box 3-Port (ISMEW90A) is the central hub for your electronic drivetrain, simplifying cable management for a clean and integrated cockpit. This essential component ensures seamless operation and reliable connectivity for Shimano's Di2 electronic shifting systems. It's designed to be a crucial part of any modern electronic shifting setup, providing a sleek and efficient connection point for your bike's electronic components, enhancing overall cycling performance and system integration.
$139.99
Owner Satisfaction
4.5
/ 5
Category Rank
672
/ 2117
#672 in Components
Price vs Category Average
+36%
Above average
Model Number
90
/ ISMEWA
Who it's for
- Mechanics needing quick access for diagnostics and firmware updates
- Cyclists wanting convenient battery charging without removing components
- Road riders managing standard dual-shifter and accessory setups
Who should skip it
- Aero-focused riders preferring a clean, integrated cockpit aesthetic
- Advanced users requiring multiple auxiliary climbing or sprint shifters
- Off-road riders concerned about debris impact and crash durability
Performance breakdown
Cable Management
Streamlines cockpit clutter for a clean, professional aesthetic.
Signal Reliability
Provides rock-solid connectivity for consistent, millisecond-perfect shifting.
Installation Simplicity
Plug-and-play design makes component integration straightforward for home mechanics.
System Compatibility
The gold standard for integrating Shimano electronic drivetrain components.
Build Durability
Weather-resistant housing protects sensitive electronics from harsh road conditions.
Cockpit Ergonomics
Low-profile footprint keeps the handlebar area sleek and unobtrusive.
Key Specs
Model Number
ISMEW90A
Port Count
3
Compatibility
Shimano Di2 electronic shifting systems
Features
- Central hub for Di2 systems
- Streamlines cable routing
- Ensures clean cockpit integration
- Enhances system connectivity
- Reliable electronic shifting
- Sleek design
- Improves performance
- Easy component connection
What customers say
The Shimano Di2 Cockpit Junction Box 3 Port is viewed as an indispensable and highly reliable core component of the electronic shifting ecosystem. Users value its flawless integration and robust performance, appreciating its set it and forget it nature once installed. This unit acts as the central connection point for shifters, battery, and derailleurs, also serving as the charging port. Its compact design contributes to a clean cockpit setup. While an investment, the component is widely accepted as necessary for the precision and durability Shimano Di2 delivers. Satisfaction is high due to its consistent, seamless operation, solidifying its status as a dependable cornerstone of modern high performance cycling.
Know before you buy
The junction box acts as the central wiring hub for your Di2 electronic shifting system. It connects your shifters to the rest of the drivetrain, allowing for clean cable routing and reliable signal transmission.
The SM-EW90A is compatible with most Shimano Di2 electronic shifting systems. However, it is specifically designed for systems that utilize the E-tube wiring platform; always verify your specific derailleur and shifter generation to ensure full compatibility.
This unit is typically mounted under the stem or integrated into the cockpit area. Its compact, sleek design is intended to sit discreetly while remaining accessible for charging and system diagnostics.
No, the junction box does not include the E-tube wires. You will need to purchase the appropriate lengths of Shimano E-tube cables separately based on your bike's frame size and cockpit setup.
Yes, this junction box features a built-in charging port. You can plug your Shimano Di2 charger directly into the junction box to charge the internal battery without needing to remove any components.
Still have a question?
Ask Hayley anything about this product before you decide.