Behind the saddle, built wider — and measurably faster
The pro field has converged on two bottles mounted close together behind the saddle as the default fast setup. It’s good — but it’s not the optimum. The Aero BTS system uses the same wide V-formation and saddle clamp as the Aero BTS PRO, and in AeroGain velodrome population testing measured 1–4 W faster than the close-together setup, and a median 5 W faster than riding with no bottles at all (n=25 athletes, 45 km/h, 0° yaw). At 60 g less and €50 less than the PRO, with 800 ml of integrated storage.
Why a wider V is faster
Behind the saddle is already a fast place for a bottle — it sits in the rider’s wake, partially filling the low-pressure void that would otherwise drag the rider back. Close-together mounting overlaps both bottles’ wakes, reducing the contribution each makes. The wide V lets each bottle work independently. For front hydration, see our front-bottle BTA system.
800 ml of integrated storage
The storage tray holds 800 ml — enough for two inner tubes, two CO2 cartridges, a pump, a tyre lever and a multitool. No top-tube bag, no zip-ties, no frame tape.
Bottle access on the move
The wide V lets you mount bottles facing inward, so you pull toward your body rather than reaching back blind. Safer on rough roads, faster through aid stations.
BTS vs BTS PRO — which one?
The PRO has a shell that hugs the bottles more tightly, 900 ml of storage vs 800 ml, and a white logo designed to match the Aero Cockpit. The standard gives you the same wide-V geometry, same bottle positions, and same saddle clamp at 60 g less and €50 less. If the extra storage and tightest possible shell matter, go PRO. If not, you’re not leaving much on the table.
Seventeen saddle fits
Available for Wove V8, Gebiomized Stride, Prologo T Galle TT, Prologo Dimension CPC Nack 143 (carbon rails), Prologo Dimension CPC Tirox 143 (alu rails), ISM PN3.1, ISM PN4.0, Specialized Sitero, Dash Integrated seat post, Selle Italia Watt Superflow, Selle Italia Watt Superflow (black rails), Selle Italia Watt Superflow 3D, Fizik Transiro Aeris, Fizik Tritone, PRO Stealth Team, PRO Aerofuel and Bontrager Hilo Pro. The next saddles are voted on by the community — follow us on Instagram.
Aero numbers from AeroGain in-house velodrome population testing, n=25 athletes, 45 km/h, 0° yaw. Full whitepaper available on request.
