Some bikes are built to be sensible and some are built to be fast. The Reacto One is firmly the second kind: it is the most uncompromising build of the current aero platform, and in Tour magazine's wind tunnel testing it returned 196 watts, comfortably under the 200 watt mark and the quickest figure in the range. Claimed weight is 7.4kg, so it is not a one-trick bike on flat roads either.

Underneath, it shares the Reacto CF5 V carbon frame and CF5 V Disc carbon fork with the rest of the top end, including clearance for 32mm tyres, 100x12mm and 142x12mm thru-axles, and a BB86 bottom bracket shell with a disc cooler. That generation of frame was developed to be more aerodynamic and lighter than its predecessor while keeping the comfort and control riders expect from the model, which is what makes a build this focused usable on a normal club run.

What sets this one apart is the drivetrain. Rather than a conventional front derailleur, it runs a single 52 tooth Rotor Alduh carbon chainset with a power meter, and a Classified Powershift rear hub that provides a second internal ratio at the push of a button. Paired with the Classified 12 speed 11-34 cassette and Shimano Dura-Ace Di2 shifting and hydraulic disc brakes, you get a full two-ring spread of gears with the tidier, more aerodynamic profile of a 1x setup and no chain drop to worry about.

The wheels are DT Swiss ARC 1100 Dicut DB 65 carbon, 65mm deep and tubeless ready, with a Continental Aero 111 700x29C at the front and a Grand Prix 5000 S TR 700x30C at the rear. That front and rear tyre pairing is a deliberate aerodynamic choice rather than a compromise. Team CW AERO one-piece carbon cockpit, Reacto V S-FLEX aero carbon seatpost and a Prologo Nago R4 PAS Nack saddle complete the bike. Note that this is the complete build, not the frameset, which is listed separately.

Features

• Reacto CF5 V carbon aero frame with matching CF5 V Disc carbon fork
• Clearance for tyres up to 700x32C
• 196 watts in Tour magazine's wind tunnel test, the fastest figure in the range
• Claimed weight of 7.4kg
• Classified Powershift rear hub giving a two-ratio internal shift with a single chainring
• Rotor Alduh carbon 52 tooth chainset with power meter
• Shimano Dura-Ace Di2 shifting with a Classified 11-34 12 speed cassette
• Shimano Dura-Ace hydraulic disc brakes
• DT Swiss ARC 1100 Dicut DB 65 carbon wheels, 65mm deep, tubeless ready
• Continental Aero 111 700x29C front and Grand Prix 5000 S TR 700x30C rear tyres
• Team CW AERO one-piece carbon bar and stem with Reacto V S-FLEX aero carbon seatpost