Equipment > Accessories > Electronic Supplies
Description
The SM-EW90-A and SM-EW90-B junction boxes mount externally beneath the stem, which puts them in a vulnerable spot during crashes, transport, or aggressive handlebar bag use. This mounting plate is the hardware that keeps the junction box attached to your cockpit. If you've cracked or lost your original mount, or you're building up a bike with a used Di2 junction box that came without its mounting hardware, this is the replacement part you need.
The mount works with both the 3-port SM-EW90-A and the 5-port SM-EW90-B junction boxes. It's a simple plate that hooks onto the stem faceplate bolts and provides a stable platform for the junction box to sit against. A separate band (sold as part number CY9082) wraps around the assembly to hold the junction box securely to the plate. The two-piece system lets you remove the junction box for service access without disturbing the mount itself.
Position matters with these external junction boxes. The SM-EW90 units house the charging port, battery level indicator, and gear adjustment buttons for older Di2 systems. Having the junction box solidly mounted means you can plug in a charger or check battery status without the unit shifting around. It also prevents the E-Tube wire connections from getting stressed by junction box movement during rides.... Read More
Features
- Mounting plate for SM-EW90-A (3-port) and SM-EW90-B (5-port) junction boxes
- Hooks to stem faceplate for secure under-stem positioning
- Used with retention band (CY9082, sold separately) to hold junction box in place
- Compatible with Dura-Ace 9070, Ultegra 6870, and earlier E-Tube Di2 systems
- Not compatible with Dura-Ace 7970 or Ultegra 6770 systems
- Replacement part for lost or damaged original mounting hardware



