Good find, but unfortunately it's a square section tube.
https://www.ebikes.ca/shop/electric-bicycle-parts/battery-accessories/triple-bob.html
This is the one mount from Grin.
Hi all,
I have recently purchased a down tube battery
and the two original water bottle bosses of the bike (aluminium frame), doesn't seem to be in the right place to fit the battery mount with integrated controller.
Chances are drill a third hole for a rivet nut. Not my favorite.
Get the...