The tidier way to carry a Varia
Nothing stops you running a Varia off the seatpost with a BTS system fitted — it works, and plenty of riders do exactly that. It just never quite looks like it belongs there. This is the alternative: a single moulded adapter that bolts to the underside of the Aero BTS cup, so the radar reads as part of the system rather than something clamped on afterwards. No shims, no rubber packers, no strap ends flapping at 45 km/h.
A quarter-turn socket, on the centreline
The rider-facing end is the standard Garmin quarter-turn socket — the same twist-and-lock your Varia already uses. The other end bolts to the cup. Mounted, the radar sits directly under the cup’s trailing edge, centred on the bike and pointing rearward.
It also sits further back than a seatpost mount puts it: at the rearmost point of the whole setup, with nothing behind it and nothing overhanging it. Clear line of sight rearward for both the radar and the light — which is the part that matters on long training rides in traffic.
We haven’t run this one through the velodrome yet, so we’re not going to put a watt number on it. What we will say: it puts the radar on the centreline behind an existing body, rather than out in clean air on a seatpost strap.
Which version do I need?
Both versions fit the Aero BTS PRO and the standard Aero BTS. What changed is the cup-side mounting interface, which was revised on 1 August 2026 — so choose by the date you ordered your system, not by which model you own. Ordered before 1 August 2026, PRO or standard: take the earlier version. Ordered after that date: take the later one.
What you get
The mount and the bolts needed to fit it to your BTS cup. 20 g on the scale, so it isn’t a weight decision. The Varia itself is yours to supply. For the cups, clamps and full systems this attaches to, see our behind-the-saddle bottle mount range.
