Your gateway into aero performance. The Merida Reacto 4000 2027 is the perfect entry point into the world of carbon aero road bikes, delivering race-inspired speed, proven geometry, and outstanding value.

Built using the same advanced CF3 carbon aero frame platform as Merida’s top-tier race bikes, the Reacto 4000 brings wind-tunnel developed aerodynamics to a more accessible price point. Paired with the ever-reliable Shimano 105 12-speed mechanical groupset and hydraulic disc brakes, it’s ready to ride fast straight out of the box.

The latest Reacto generation is lighter, more aerodynamic, and more versatile than ever, now with clearance for up to 32mm tyres, making it ideal for UK road conditions. Whether you're getting into racing or upgrading to your first aero bike, the Reacto 4000 delivers performance you can grow into.

Key Features

• CF3 Carbon Aero Frame – same aero platform as Merida’s top models
• Shimano 105 12-speed groupset – reliable, smooth mechanical shifting
• Hydraulic disc brakes – powerful, consistent braking in all conditions
• Up to 32mm tyre clearance – improved comfort and grip
• Internal cable routing – clean looks and reduced drag

Size Guide (approx.):

• XXS: 150–160cm
• XS: 160–170cm
• S: 170–175cm
• M: 175–180cm
• L: 180–185cm
• XL: 185–195cm

Specification - 

Frame & Fork

• Frame: Merida Reacto CF3 Carbon, aero tube design, internal cable routing, flat mount disc, 12x142mm thru-axle
• Fork: Merida Reacto CF3 Carbon Disc, 12x100mm thru-axle

Drivetrain

• Shifters: Shimano 105 R7100, 12-speed mechanical
• Front Derailleur: Shimano 105 R7100
• Rear Derailleur: Shimano 105 R7100
• Chainset: Shimano 105 R7100, 50/34T
• Cassette: Shimano 105 R7100, 12-speed (11-34T)
• Chain: Shimano 12-speed

Brakes

• Brakes: Shimano 105 hydraulic disc
• Rotors: Shimano RT70, 160mm front / 140mm rear

Wheelset & Tyres

• Wheels: Merida Expert SL Disc (tubeless ready)
• Tyres: 700c road tyres, up to 32mm clearance

Cockpit

• Handlebar: Merida Expert Aero handlebar
• Stem: Merida Expert stem
• Headset: Integrated

Finishing Kit

• Seatpost: Merida Reacto aero carbon seatpost
• Saddle: Merida Comp SL