External/Cockpit junction A

The External junction box A SM-EW90 used to be the junction box everyone had on their bikes. DURA-ACE 9150 introduced the EW-RS910 junction A, which has been the go-t0 junction box for any new bike since then.

While it is available in a 3 and 5-port version, the latter is rarely used and most people seem to opt for the 3-port version of the junction box.

SM-EW90-A junction box

Details & specifications

Shimano model codeSM-EW90-A (3-ports), SM-EW90-B (5-ports)
Shimano model nameExternal/Cockpit Junction A
Weight10 g
SeriesUltegra 6770, Ultegra 6780, Ultegra R8000, DURA-ACE 9070, DURA-ACE R9150
Downloads SM-EW90-A manual
Buy on Amazon View on Amazon.com (opens new window)
Search on eBay Search on eBay (opens new window)