Skip to content
  • 🔥 New arrivals and big savings! 🔥
  • 🔥 New arrivals and big savings! 🔥
Bicycle Parts StoreBicycle Parts Store
  • Menu
  • Shoes
    • Sport MTB shoes
    • Walking MTB shoes
    • Road track shoes
    • Boots for downhill
    • Winter shoes
    • Women shoes
  • Components
    • Brakes
    • Rear derailleurs
    • Cranksets
    • Gear Shifters
    • Chains
    • Pedals
    • Cassettes
    • Front derailleurs
    • Bottom brakes
    • Hubs
    • Accessories
    • Wheels
  • Accessories
    • Shoes
    • Electronics & Bike Computers
  • Parts
    • Cassettes
    • Cranksets & Parts
    • Derailleurs & Parts
    • Shifters
    • Wheels & Parts
    • Brakes
    • Cables & Housing
    • Chainrings & Accessories
    • Bottom Brackets & Parts
    • Pedals & Cleats
    • Chains & Accessories
    • Groupsets
    • Seatposts & Clamps
    • E-Bike Accessories
    • Suspension
    • No products in the cart.

      Return to shop

  • Cart

    No products in the cart.

    Return to shop

Home / Parts / Cables & Housing
  • Shimano Dura-Ace FD-7900 Front Derailleur Cable Fixing Assembly Bolt -Bicycle Parts Store y5lb98020
  • Shimano EW90-A/B Di2 Junction Box Hook (Mounting Plate) -Bicycle Parts Store y7fe98010
Sale!
Shimano EW-SD50 Di2 External B Junction Box
Shimano EW-SD50 Di2 External B Junction Box - Image 2
Shimano EW-SD50 Di2 External B Junction Box - Image 3
Shimano EW-SD50 Di2 External B Junction Box - Image 4
Shimano EW-SD50 Di2 External B Junction Box -Bicycle Parts Store ismjc40 1
Shimano EW-SD50 Di2 External B Junction Box -Bicycle Parts Store ismjc40 2
Shimano EW-SD50 Di2 External B Junction Box -Bicycle Parts Store ismjc40 3

Shimano EW-SD50 Di2 External B Junction Box

$31.49 Original price was: $31.49.$22.04Current price is: $22.04.

Buy Now
SKU: CGVYZ 308988 Categories: Cables & Housing, Parts
  • Expertly Sourced, Quality Guaranteed
  • Efficient and effective customer service, online.
  • Free and fast shipping worldwide
  • Safe Transactions, Always
Browse
  • Accessories
    • Electronics & Bike Computers
    • Shoes
  • Components
    • Accessories
    • Bottom brakes
    • Brakes
      • Adapters
      • Brake disks
      • Brake levers
      • Brake pads
      • Brake shoes
      • Disc brakes
      • Hydraulic hose
      • Road bike breaks
    • Cassettes
    • Chains
    • Cranksets
      • Chainrings
      • MTB Cranksets
      • Road cranksets
    • Front derailleurs
    • Gear Shifters
      • MTB Gear Shifters
      • Road bike gear shifters
    • Hubs
    • Pedals
      • Accessories
      • Combined
      • Platform
      • Road
      • SPD
    • Rear derailleurs
      • Accessories
      • MTB derailleur
      • Road derailleur
    • Wheels
  • Parts
    • Bottom Brackets & Parts
    • Brakes
    • Cables & Housing
    • Cassettes
    • Chainrings & Accessories
    • Chains & Accessories
    • Cranksets & Parts
    • Derailleurs & Parts
    • E-Bike Accessories
    • Groupsets
    • Pedals & Cleats
    • Seatposts & Clamps
    • Shifters
    • Suspension
    • Wheels & Parts
  • Shoes
    • Boots for downhill
    • Road track shoes
    • Sport MTB shoes
    • Walking MTB shoes
    • Winter shoes
    • Women shoes
  • Uncategorized
  • Description
  • Reviews (0)

This is the Shimano Ultegra Di2 External Junction Box for connecting the two derailleurs, battery, and cockpit controls in a Shimano Di2 electronic shifting system. This junction works with all Di2 with e-tube wired system components as long as firmware is updated to same version between all the connected components.

Features:

  • Mounts underneath the bottom bracket shell
  • Frame Junction Box connects via SD50 E-tube wires to four different points: front derailleur, rear deailleur, cockpit junction box and battery mount
  • Use Di2 system checker to update component firmware from http://e-tubeproject.shimano.com/
  • All Di2 components on the bicycle require the same firmware version. Using Di2 components with different firmware versions may cause malfunctions

    Sizing     Sizing

This product was added to our catalog on March 7, 2018

Reviews

There are no reviews yet.

Be the first to review “Shimano EW-SD50 Di2 External B Junction Box” Cancel reply

Related products

Sale!
Shimano Brake Cable Kit (Black) (Stainless) (1.6mm) (1800/2000mm) (Road Cable) (w/ Housing)
Quick View

Parts

Shimano Brake Cable Kit (Black) (Stainless) (1.6mm) (1800/2000mm) (Road Cable) (w/ Housing)

$13.99 Original price was: $13.99.$9.79Current price is: $9.79.
Sale!
Shimano Nexus/Alfine Track-Type Dropout Left Non-Turn Washer (6L White)
Quick View

Parts

Shimano Nexus/Alfine Track-Type Dropout Left Non-Turn Washer (6L White)

$6.29 Original price was: $6.29.$4.40Current price is: $4.40.
Sale!
Shimano Sora R3000-CG Chainring (Black) (2 X 9 Speed) (110mm BCD) (Outer) (50T) (Chainring Guard Model)
Quick View

Chainrings & Accessories

Shimano Sora R3000-CG Chainring (Black) (2 X 9 Speed) (110mm BCD) (Outer) (50T) (Chainring Guard Model)

$36.99 Original price was: $36.99.$25.89Current price is: $25.89.
Sale!
Shimano PD-M520 Mountain SPD Pedals (White)
Quick View

Parts

Shimano PD-M520 Mountain SPD Pedals (White)

$50.00 Original price was: $50.00.$35.00Current price is: $35.00.
Sale!
Shimano Ultegra FC-6750 Chainrings (Silver) (2 X 10 Speed) (110mm BCD) (Inner) (34T)
Quick View

Parts

Shimano Ultegra FC-6750 Chainrings (Silver) (2 X 10 Speed) (110mm BCD) (Inner) (34T)

$14.49 Original price was: $14.49.$10.14Current price is: $10.14.
Sale!
Shimano Rear Derailleur Chain Stabilizer (XTR RD-M9000, XT RD-M8000, SLX RD-M7000-11)
Quick View

Parts

Shimano Rear Derailleur Chain Stabilizer (XTR RD-M9000, XT RD-M8000, SLX RD-M7000-11)

$15.75 Original price was: $15.75.$11.03Current price is: $11.03.
Sale!
Shimano Ultegra CN-6600 Chain (Silver) (10 Speed) (116 Links)
Quick View

Chains & Accessories

Shimano Ultegra CN-6600 Chain (Silver) (10 Speed) (116 Links)

$28.34 Original price was: $28.34.$19.84Current price is: $19.84.
Sale!
Shimano Sora FC-R3000 Outer/Middle Chainring Bolts (4)
Quick View

Parts

Shimano Sora FC-R3000 Outer/Middle Chainring Bolts (4)

$10.25 Original price was: $10.25.$7.18Current price is: $7.18.
OUR SHOP
  • My account
  • Checkout
  • Cart
  • Payment Method
CONTACT
  • About Us
  • Contact Us
  • FAQ
  • Returns & Exchanges
CUSTOMER SERVICES
  • Privacy Policy
  • Shipping & Returns
  • Term and Conditions
  • Delivery
STAY IN TOUCH

Sign up for exclusive offers, original stories, events and more.

    Copyright 2025 © www.usbikepartssale.com
    • Shoes
      • Sport MTB shoes
      • Walking MTB shoes
      • Road track shoes
      • Boots for downhill
      • Winter shoes
      • Women shoes
    • Components
      • Brakes
      • Rear derailleurs
      • Cranksets
      • Gear Shifters
      • Chains
      • Pedals
      • Cassettes
      • Front derailleurs
      • Bottom brakes
      • Hubs
      • Accessories
      • Wheels
    • Accessories
      • Shoes
      • Electronics & Bike Computers
    • Parts
      • Cassettes
      • Cranksets & Parts
      • Derailleurs & Parts
      • Shifters
      • Wheels & Parts
      • Brakes
      • Cables & Housing
      • Chainrings & Accessories
      • Bottom Brackets & Parts
      • Pedals & Cleats
      • Chains & Accessories
      • Groupsets
      • Seatposts & Clamps
      • E-Bike Accessories
      • Suspension
    • Login

    Login

    Lost your password?

    Register

    Your personal data will be used to support your experience throughout this website, to manage access to your account, and for other purposes described in our privacy policy.