I'm looking to buy an Aero water bottle holder cage for my BMC TT aero seatpost but I honestly don't know how they work and if there is any adapter available out there.
Here's the one I was looking at from Profile Design:
http://www.ebay.ca/itm/White-Profile...item337ed051f7
And here's the wing shaped seatpost it gotta fit:
Is there anyone who had this problem before and what's the best way to make sure it fits before buying online?