That is OK, my track bike doesn't have cages either. For me, either ride with a bottle in the back pocket of the jersey, or stop at a store mid ride for a bottle and just chug it. If I am riding with a bag, usually have one in my bag. Not many options for aero tubed frames. Tried the ass rocket, and it is just that. Launches out over the smallest bumps.

Not sure what the OP does. Only answering for myself here.