Are there 7x9 rail clamps/wedges sold anywhere for this kind of TanTan seatpost? The default one fits only thinner rails, and if any other bits came with it, I must have misplaced them...
I bought this one after borking one of the wedges; it seems to be working fine.
https://www.aliexpress.us/item/3256807328701238.html (pick the right version)
(My TanTan shipped with both the 7x7 and the 7x9 clamp, for what it's worth.)