Aero hydration systems are designed around one constraint: drink without sitting up. BTA (between-the-arms) systems mount to your aerobars and position a bottle or reservoir directly in front of you — the straw reaches your mouth while you stay locked in position. This is the fastest approach for flat-course racing where you're on the bars the whole time. Rear systems mount behind the seat and are preferred when you want more total volume or are racing on courses where you'll occasionally sit up. Many athletes run both: a BTA for frequent small sips and a rear system as reserve volume for longer efforts like a full Ironman bike leg.

The 51 products span both positions. TriRig's BTA Pro Kit is the premium front option — a carbon aero bottle system designed for minimal drag in the center position. Profile Design covers BTA and aerobar-mount systems across the HSA, RM, and RZ3 lines for different bar setups. XLAB leads on rear systems with the Carbon Wing (saddle-mount) and Delta series (rear-cage-mount) in multiple volume configurations. Cervelo's adjustable rear mount offers a clean, bike-specific option. Elite's Buta covers the front-position end at a more accessible price point.

Build out your triathlon setup with aerobars, triathlon accessories, and the full XLAB triathlon components collection. For conventional hydration on training rides, see water bottles and cages.