Building a Di2 bike isn't all that hard, but every little bit helps. Over the years I've written several posts on Di2 bike building as well as little tips, tricks and installation guides. If you're missing anything however, just send me a message.
Whether you're building a road bike, MTB, gravel bike or tandem doesn't really matter - they all require the same base components: a battery, electric wires, and a derailleur. If you're building an 11-speed Di2 bike, you'll also need a Junction A, and probably a Junction B as well.
The most commonly used components are:
- EW-SD50 Electric Wire - for 10-speed and 11-speed Di2
- EW-SD300 Electric Wire - for EP8 series Di2, and 12-speed Di2
- BT-DN110 Internal Battery (11-speed Di2) / BT-DN300 (12-speed Di2)
- Junction A, for 11-speed Di2 only: EW-RS910 handlebar / frame or SM-EW90-A below-the-stem
- 10/11-speed Di2 SM-BCR2 Battery Charger
- 12-speed Di2 charging cable
For a list of all known Di2 Components, have a look at the component overview page.
Installing components on your bike
To help you choose and install your Di2 parts I've written these pages:
- 11-Speed Di2: Select your Di2 components - What parts do you need?
- 11-Speed Di2: How to determine Di2 wire lengths for your bike
- Di2 Installation Guides
- Where to find Shimano documentation (dealer manuals, specs, exploded views)
- Di2 Compatibility Guide - mix different series on the same bike
Although not directly related to building your own bike, these pages are good to read.
- Build log: Cinelli Veltrix Disc - R8050 Di2 with FC-R9100-P Power Meter
- Wireless / BluetoothLE // ANT Troubleshooting guide
- Update your Di2 Firmware
- Di2 Software and Tools
- In-depth guide on upgrading your old Di2 bike