Shimano Dura-Ace Di2 SM-EW90 5-Port Junction Box
Expected to ship within 10 Days
Delivered fully assembled and tuned by Bike Mart—ready to ride right at your doorstep within 10 miles of any DFW location.
What is the Bike Mart Return policy?
What is the Bike Mart Return policy?
Bike Mart offers a 14-day return and 30-day exchange policy in effect on qualifying items. Restocking fee may apply for "At Warehouse" Items. Read More
What Financing options does Bike Mart offer?
What Financing options does Bike Mart offer?
Financing is easier than ever at Bike Mart. With Synchrony Financial, you can choose:
- 0% APR for 6 months — on orders under $999
- 0% APR for 12 months — on orders of $1,000 or more
We also support HSA/FSA Funds with TrueMed, Shop Pay Installments and PayPal Financing.
Ship
Get your bike or equipment delivered to your home directly from Bike Mart via our FedEx or USPS Carrier partners. Adult signature is required for all bike deliveries and for equipment & gear deliveries over $500.
For orders that include a bike, it will be professionally pre-built and shipped to your home with minimal assembly needed. While we try to make it as easy as possible, basic mechanical skills and proper tools are required.
If you decide to take your bike to a local bike shop for assembly, additional fees will apply.
Pickup
We’ve made it easier than ever to get the gear and bikes you love—fast. With our Buy Online, Pick Up In Store (BOPIS) option, you can shop online and pick up your items at your convenience from any of our six DFW locations.
The best part about picking up at a Bike Mart location is that you get the same high quality service with the convenience of having the exact bike or part.
Bikes / Car Racks will be assembled and installed at no extra charge and might require additional processing time for assembly.
Delivery
When you select "Home Delivery" at checkout. Your bike will be professionally assembled and the closest Bike Mart store will call you to schedule the delivery.
We offer home delivery for bike purchases only within 10 miles of a Bike Mart location. Contact us if you live beyond 10 miles and we can discuss more options. Additional fees may apply.
In stock bikes will be delivered within 7 days. Warehouse bikes will delivered within 14 days*.
Shimano Dura-Ace Di2 SM-EW90 5-Port Junction Box
Overview
Overview
Sometimes called Junction A, or seen as the connection box sitting under the stem, this is where the wires need to be plugged in to give directions to the front and rear derailleurs and get electricity from the battery. It also is how you charge Di2 batteries while leaving them on the bike.
There are two versions of the Junction Box. SM-EW90-A is the three-port version. SM-EW90-B is the five-port version.
Three ports is the minimum. This represents a wire coming from one shifter, a wire coming from a second shifter, and a wire going to the junction box, aka junction B, by the bottom bracket. With three ports, you can either run shifting from the brake levers or the bar ends (aka aero bars). You can't do both. If you want the option to expand your system at all, the five-port box is probably the better choice. That, or you'll upgrade to the five-port box when you expand your system. However, if you're looking to add Sprinter Switches (SW-R610) or Climber Switches (SW-R600), these plug into the ports on the drop bar integrated levers, so you don't need the five-port box if you think you'll go this route.
The Junction Box comes with mounting plate as well as two rubber straps to affix the box to your bike. The box also has a port for on-bike charging of Di2 batteries and reprogramming and updating your system.
The Shimano Di2 SM-EW90 Junction Box gathers the shift wires before they communicate with the derailleurs.
