The Di2 SM-BMR1 Battery Mount secures the Ultegra SM-BTR1 Battery* to your frame.
This integral components is available in two lengths, Long and Short. The Long version is compatible with most bikes, it's designed to attach to the seat tube or down tube via a single water bottle boss. The Long mount comes in internal or external variations depending on which cable routing your bike uses.
*Note: This product is also compatible with Dura-Ace 9070 Di2 but requires a firmware update. You will need the SM-PCE1 PC Tool to install this update, which can be downloaded at http://e-tubeproject.shimano.com. Alternatively, the most recent firmware can be installed at your local Shimano Service Center.
A description of the different types of bottom brackets, the bearings for bike cranks.
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