Aero BTS system

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 2–12 W faster than riding with no bottles at all (n=17 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 (1–2 W additional advantage), 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.

Eight saddle fits

Available for Wove V8, Gebiomized Stride, Prologo T Galle TT, ISM PN3.1, Specialized Sitero, Dash Integrated seat post, Selle Italia Watt Superflow, and Fizik Transiro Aeris. The next saddles are voted on by the community — follow us on Instagram.

Aero numbers from AeroGain in-house velodrome population testing, n=17 athletes, 45 km/h, 0° yaw. Full whitepaper available on request.