Install the Di2 battery in the fork steerer
Where do you install your Di2 internal battery if the seatpost isn't an option? On a full-suspension mountain bike, or if you run a dropper post? The fork steerer is a pretty good alternative!
The PRO Fork Steerer Battery holder, or PRO GAP CAP Di2 as it is officially called, allows you to put your Di2 battery in the fork steerer.
It is a short expander with an integrated battery holder and it fits 1 1/8" steerer tubes.
Note: The minimum fork steerer length is 180mm. If yours is shorter than this, the battery won't fit. I have written an Installation Guide showing you how to install the battery holder.
Why would you ever install the battery in the steerer, you ask?
Well.. not all bicycles have a seatpost capable of holding a Di2 battery. Think Canyon's VCLS seatposts, dropper posts, or full-suspension mountain bikes. This expander is a pretty good solution to that problem, especially when used together with PRO stems (like the PRO Vibe for example).
There are two versions of this battery holder, so make sure you get the right one:
There are a couple of other options if you cannot place your battery in the seatpost. The external-mount-for-internal-battery SM-BTC1 is one, but it's a bit chunky. Another option would be to put the battery in the downtube (if you can), or to use an external battery with the external battery holder.
Where do you install your Di2 internal battery if the seatpost isn't an option? On a full-suspension mountain bike, or if you run a dropper post? The fork steerer is a pretty good alternative!
Learn how to install your Di2 BT-DN300, BT-DN110 or SM-BTR2 battery in your bike's seatpost.