Felt provides an Owner’s Manual and Supplemental Manual which covers component installation and wiring for the IAx. Rather than repeat that info, this article will outline some specifics for Shimano Di2 and the bottom bracket.

Shimano Di2

For this build, I used Shimano Ultegra Di2 6870 series. The hardest part was figuring out which components were needed, here is the complete list:

  • FD-6870 Road Bike Front Derailleur Brazed-On
  • RD-6870 Road Bike Rear Derailleur 11 Speed
  • SW-R671 TT Shifter Set
  • ST-6871 TT Brake/Shifter Bar End Set
  • EW90-B Cockpit Junction A Box 5-Port
  • SM-JC41 Internal Routing Junction B Box (x2)
  • SM-BTR2 Internal Battery
  • EW-SD50 E-tube Electric Wire (1 x 1000mm, 3 x 500mm, 1 x 300mm)
  • BCR2 Internal Battery Charger E-tube

When Wires Will Not Reach

Both the shifter and brake/shifter sets came with e-tube wires permanently installed. Unfortunately, the brake/shifter wires were not long enough to reach the junction A box when routed through the bars/frame. Luckily, a junction B box can be used to “extend” these wires. Just connect both brake/shifter wires to a junction B box, then connect that to the junction A box with another wire.

Bottom bracket

The IA10 is a BB30 frame, but I wanted to use a Shimano crank which has a different bottom bracket standard (SM-BBR60). To install the crank, I used the Wheels Mfg BB30 Adapter For Shimano, it fit nicely.