For a short bike leg of a triathlon, or a time trial, the Speedfil Hydration F2 works to get your hydration to you so that you don't compromise your carefully calculated aerodynamic position. The F2 fits into a standard down tube water bottle holder so that you won't need to mount any extra hardware to your bike. And, the bottle is easily removable for cleaning. The threaded cap works with any Specialized thread compatible water bottle both 21 and 24oz sizes. It's refillable on the fly so you'll never dehydrate. The long tubing positions near your handlebars for hands free access. And don't worry, all you need to do is prime the system once and your liquid is immediately available, no more sucking up air waiting for the tube to fill, and it stays full throughout your ride.