Weighing just 25g, the Zipp carbon bottle cage is our preferred cage to fit to the Hydrotail.  The Cyclespeed team prefer the Zipp cages over all other brands for one very simple reason - they dont spit bottles.  The aggressive carbon retaining clip that is an integrated part of the cage and the snug fit ensure that bottle ejections are almost impossible to achieve.  Since we started fitting Zipp cages to our Hydrotails we have only known of one incident where an ejection occured (and the bicycle involved in that ejection hit the pothole so hard the front wheel was damaged...).

That's why we recommend Zipp bottle cages as standard operating equipment for your Hydrotail.