Support de bouteille arrière
Wider than the pro default. Measurably faster.
Behind-the-saddle hydration has become the pro-field standard — every serious tri and TT setup now runs two bottles behind the saddle. The question is how they're mounted. Most systems put the bottles close together. AeroGain mounts them wide apart, in a V-formation, and in velodrome population testing that spacing measured 1–4 W faster than close-together mounting (n=17 athletes, 45 km/h, 0° yaw). The wider the V, the less the bottles' aerodynamic wakes cancel each other out.
Why wider is faster
Behind the saddle, each bottle sits in the rider's wake, partially filling the low-pressure void that would otherwise drag the rider back. When bottles are mounted close together, their wakes overlap — each bottle reduces the benefit the other provides. Opening them into a wide V lets each bottle work independently. The physics is straightforward; most systems don't exploit it because wider spacing is harder to engineer securely.
What's in this category
- Aero BTS PRO system — the flagship. Tightest shell geometry, 900 ml integrated storage, 1–2 W faster than the standard BTS. Banned at Ironman Texas when ridden by Vincent Luis on debut — now fully approved by World Triathlon and Ironman.
- Aero BTS system — the standard. Same wide-V bottle positions and saddle clamp as the PRO. 800 ml storage, 60 g lighter, €50 less.
- Aero BTS PRO cup — PRO cup only, without saddle clamp. For riders who already have a compatible clamp.
- Aero BTS cup — standard cup only, without saddle clamp.
- Aero BTS Carbon Saddle Clamp — saddle-specific, carbon-rod clamp. Sold separately. Fits both cups.
How to choose
Starting from scratch? Buy the full system — PRO or standard. Both include the saddle clamp. Choose PRO for the tightest shell (1–2 W faster than the standard BTS), 900 ml of storage, and a white logo that matches the Aero Cockpit. Choose the standard for the same wide-V geometry at 60 g less and €50 less.
Already have a clamp? Buy the cup only. The PRO cup (900 ml) and standard cup (800 ml) both fit all Aero BTS Carbon Saddle Clamps.
Need a clamp? The Aero BTS Carbon Saddle Clamp is sold separately. Each variant is tooled to one specific saddle — select yours from the variant list.
Frequently asked questions
How is this different from other behind-the-saddle systems?
Bottle spacing. Most systems mount bottles close together — but close-together mounting overlaps the bottles' aerodynamic wakes, reducing the benefit each one contributes. The AeroGain wide V spaces them further apart so each bottle fills the low-pressure zone independently. That is why our velodrome data shows 1–4 W of advantage over the close-together default.
What's the difference between the PRO and the standard?
Both use the same bottle positions and the same saddle clamp. The PRO adds a shell that hugs the bottles more tightly (1–2 W over the standard), 900 ml of storage vs 800 ml, and a white logo to match the Aero Cockpit. The standard is 60 g lighter and €50 less.
Can I upgrade from the standard cup to a PRO cup later?
Yes. The saddle clamp is shared between both systems. Buy the Aero BTS PRO cup and it mounts directly to your existing clamp.
Aero figures from AeroGain in-house velodrome population testing, n=17 athletes, 45 km/h, 0° yaw, vs. two 750 ml bottles mounted close together. Full whitepaper available on request.
