We wind-tunnel tested three hydration setups to find the fastest way to ride with three bottles.
Fast: A fixed vertical water bottle with a drinking straw combined with two water bottles on the frame was the easiest setup to drink from, but created more drag than the other setups we tested.
Faster: Swapping the fixed bottles for a standard cage-and-bottle between the forearms saved aerodynamic drag. It also made swapping bottles at aid stations easier, but drinking became more difficult.
Fastest: Moving two frame bottles to a carrier mounted behind the saddle again boosted speed. Coupled with the horizontal bottle on the aerobars, this system created the least drag, but refilling was also slightly more difficult than with the other setups.