Merida Reacto 5000 Gen 5 105Di2 Road Bike

The Merida Reacto 5000 Gen 5 is an aero carbon road bike that brings Merida's fastest-ever frame down to an accessible price point. Benefit from our fastest ever road bike frame without blowing the budget. The REACTO 5000 pairs our latest CF3 carbon fibre aero frame with high-value kit such as Shimano's benchmark 105 Di2 electronic groupset to create a ride that's almost as fast as our pro level bikes but at a fraction of the cost. With a tubeless-ready Vision 35 wheelset and quality Continental tyres, it's a blend of speed, performance and value that's hard to beat.

 

Key highlights

• Category: Aero carbon road bike, disc brake, electronic shifting
• Brand: Merida (Taiwan), REACTO Generation V aero platform
• Frame: REACTO CF3 V carbon, approx. 1,185 g in size M, tyre clearance up to 32 mm
• Groupset: Shimano 105 Di2, 12-speed electronic shifting with hydraulic disc brakes
• Wheels: Vision Team 35 tubeless-ready wheelset with Continental Grand Prix TR 28 mm tyres
• Seatpost: MERIDA REACTO V S-FLEX carbon aero post for extra comfort
• Best for: Riders who want race-bike aerodynamics and Di2 shifting without the price of a top-tier build

The thrill of speed is what unites road cyclists. Whether professional or amateur, the fundamental goal is to push harder, chase speed and break free. Nothing embodies this better than the REACTO. The latest generation of the REACTO builds on the previous model, with fundamental changes that further improve its aerodynamics, reduce its weight and offer tyre clearance up to 32 mm, all while maintaining the comfort and control the REACTO is known for. Whatever your focus — low drag, low weight, or all-round performance — you will find the perfect REACTO in Merida's line-up.

 

Who is the Reacto 5000 for?

The Reacto 5000 suits road cyclists who race, do club rides or fast group rides in Hong Kong (the Tolo Harbour cycle track towards Tai Mei Tuk, Shek O, Route Twisk) and want an aero frame with electronic shifting, without paying for a carbon cockpit or deep-section carbon wheels. Shimano 105 Di2 gives crisp, consistent shifting in Hong Kong's humid, hilly conditions with less cable maintenance than a mechanical groupset. Riders who prioritise all-day comfort on longer endurance rides, or who want the lightest possible climbing bike, may be better served by an endurance model such as the Merida Scultura Endurance, or the lighter-weight Reacto Team build (see comparison below).

 

Aero frame, race-proven platform

The REACTO CF3 V frame is the same aerodynamic platform used across the whole Generation V Reacto range, from the 4000 up to the flagship Reacto Team and 10K. You get the aero benefit of the top-end frame while the 5000's build kit keeps the price down.

Shimano 105 Di2 electronic shifting

105 Di2 is Shimano's entry point into wireless-feel, button-shift electronic groupsets, with 12-speed gearing and hydraulic disc brakes. Shifting is consistent regardless of how hard you're pushing on the pedals, which matters when you're sprinting for a Strava segment or shifting mid-climb.

DISC COOLER technology

Merida's DISC COOLER fins on the frame and fork help dissipate heat from the disc brake rotors on long descents, for more predictable braking feel — useful for Hong Kong's mountain descents such as Tai Mo Shan or Shek O.

Tubeless-ready wheels and tyres

The Vision Team 35 wheelset and Continental Grand Prix TR 28 mm tyres are tubeless-ready (tubeless tape and valves not included), so you can convert to tubeless later for a lower puncture risk without changing wheels.

 

How to choose your frame size

The Reacto 5000 Gen 5 is offered in 7 frame sizes (3XS to XL). Merida publishes reach, stack and stand-over height for each size (see the geometry table below) but does not publish a simple rider-height chart for this model. Because reach and stack — not just seat tube length — determine your riding position on an aero frame, we recommend checking the full geometry table below against your current bike's measurements, or booking a Jollymap Bike Fit session before you buy (see below).

 

Reacto 5000 vs Reacto 6000 vs Reacto Team

The Reacto Team shares the same REACTO Generation V aero platform and identical geometry (reach, stack, head/seat tube angles) as this 5000. The Reacto 6000 sold at Jollymap is the 2024 model year — it uses the previous-generation REACTO CF3 IV platform, with its own geometry and a lower maximum tyre clearance, so it is not a direct sibling of the 5000:

Prefer a lighter climbing-focused bike with the same race geometry as the Reacto, but less emphasis on aerodynamics? Compare with the Merida Scultura 5000, which uses identical geometry to the Reacto but a lighter frame (approx. 997 g vs 1,185 g).

 

Specifications

Specifications source: Merida official global product page (merida-bikes.com).

Geometries

 

Professional Size Fitting and Bike Fit Services

Unsure about sizing or want to ride more efficiently while avoiding injury? Welcome to learn about Jollymap's size fitting and bike fit services.

 

FAQ

What's the difference between the Reacto 5000 and Reacto 6000?

The 6000 sold at Jollymap is the 2024 model year, which predates this 5000's Generation V platform: it uses the previous REACTO CF3 IV frame, a 30 mm aluminium wheelset and has a lower maximum tyre clearance (30 mm vs 32 mm on the 5000). Both use the same Shimano 105 Di2 groupset. If you specifically want the newer Generation V aero platform in a higher-tier build, compare with the Reacto Team instead.

Is the Reacto 5000 suitable for a beginner road cyclist?

Yes, with some caveats. The Reacto's aero-race geometry (lower stack, longer reach than an endurance bike) rewards riders who are already reasonably flexible and comfortable in a lower position. First-time road riders who want a more upright, forgiving position may prefer an endurance-focused frame such as the Merida Scultura Endurance; a Jollymap Bike Fit session can confirm which position suits you.

What is the maximum tyre size on the Reacto 5000?

The frame and fork both accept up to 700x32C tyres. It ships with 700x28C Continental Grand Prix TR tyres, so there's room to size up for extra comfort or grip without changing the frame.

Do the wheels need to be set up tubeless, or can I ride them with inner tubes?

You can ride them with inner tubes straight away. The Vision Team 35 wheelset and Continental Grand Prix TR tyres are tubeless-ready, but tubeless tape and valves are not included, so converting to tubeless is an optional upgrade you can do later.

How do disc brakes on the Reacto 5000 hold up in Hong Kong's hot, humid weather?

Hydraulic disc brakes are well suited to Hong Kong's summer heat and sudden rain, since braking performance is far more consistent in the wet than rim brakes. Merida's DISC COOLER fins on the frame and fork help manage heat build-up on long descents. As with any hydraulic system, we recommend a periodic brake fluid and pad check, especially before long descents like Tai Mo Shan.

How does Shimano 105 Di2 electronic shifting differ from a mechanical groupset?

105 Di2 shifts gears using small electric motors triggered by button presses rather than cables, so shifting stays light and precise even after miles of use, and there are no cables to stretch or corrode. The battery is charged via a port on the rear derailleur rather than anywhere on the frame; see Shimano's official manual for the expected charge interval for your riding volume.

How does the Reacto 5000 compare to the Merida Scultura?

The Scultura 5000 uses identical race geometry to the Reacto, so it's not a more upright or "endurance" bike — the difference is that its frame is lighter (approx. 997 g vs 1,185 g) because it isn't shaped for aerodynamics, so it suits riders who prioritise low weight for climbing over aero speed. If you want a genuinely more relaxed, comfort-focused geometry, look at the Merida Scultura Endurance range instead of the standard Scultura. If you're unsure which suits you, our Bike Fit team can compare the geometries against your current position.

 

Last updated: September 2026