With the 2021 REACTO, MERIDA present the latest evolution of their aero bike. To find out what its strengths and weaknesses are, we let the Bahrain McLaren team spec bike compete against a Porsche 911 on the roads of the Black Forest.

MERIDA REACTO TEAM-E | 7.52 kg in size M | € 10,299 | Manufacturer’s link

The king is dead, long live the king! According to this motto, MERIDA are celebrating the fourth generation of their REACTO aero bike. Based on the DNA of the previous model, MERIDA designed the REACTO IV with numerous features and in-house innovations, ready to tackle a new decade and all the upcoming UCI ProTour and hobby races. We were given the opportunity to test the brand new REACTO extensively before the official launch. Admittedly, we are neither ProTour athletes, nor have MERIDA provided us with a McLaren from the team pool. But the roads meandering through the Black Forest, Robin’s Porsche 911 and our bratwurst loaded bodies provided ideal conditions to put the new REACTO through its paces nonetheless. Before we delve into the actual review, let’s have a look at what’s beneath the hood of this new aero bike.

The concept of the brand new MERIDA REACTO

The much cleaner design of MERIDA’s fourth-generation REACTO compared to its predecessor is said to have come down to optimised aerodynamics. This was their priority in developing the new model and it should be significantly more streamlined compared to the REACTO III thanks to the fully integrated cable routing, a deeper seat tube, improved seat stay profiles and a new fork design. The so-called yaw angle has been increased and the frontal air flow has been improved with the help of Computational Fluid Dynamics (CFD) and tests in the wind tunnel. This should enable the rider to better utilize the sailing effect encountered in crosswinds.

On the flagship models of the MERIDA REACTO, the cables are routed internally throughout the bike via the Vision cockpit. The GPS mount has also been beautifully integrated and is compatible with all the common devices!

Besides optimising the aerodynamics, the designers also wanted the new REACTO to be a fun and versatile bike. Similar to the recently introduced SCULTURA ENDURANCE, tire clearance is ample you’re officially allowed to fit tires up to 700 x 30C. So there is plenty of scope for those who want to tackle cobblestones or simply want a more comfortable ride. The MERIDA S-FLEX seat post as featured previously on the REACTO III should also provide additional comfort on the latest model. The standout features of the seat post are the integration of a rear light into the recess that gives the post its flex and the so-called Flip Flop head, which allows you to adjust the position of the saddle. Integration was equally important when it came to the cable routing, as this is kept internal throughout, entering the frame via the Vision Metron 5D ACR cockpit. For this purpose, the head tube has been enlarged and now features a 1½” to 1¼” headset. You’ll find other modern standards such as 12 mm Thru-Axles front and rear as well as a PF86 bottom bracket, making the frame compatible with a wide range of components. Not all features are conducive to aerodynamic improvement. Nevertheless, the designers claim to have managed to design the bike in such a way as to make it 1 watt more efficient than its predecessor, requiring 209 watts at 45 km/h.

The increase in clearance between the tire and the frame allows you to fit wider tires and is intended to guide airflow more efficiently

The new REACTO will only be available with disc brakes and a carbon frameset. The high-end models feature a CF5 level frame while the more affordable alternatives come with a CF3 level frameset. Both frames have the same geometry and, according to the manufacturer, should offer similar ride characteristics. The main difference between the two frames is the grade of carbon fibres used and the time invested in developing the carbon layup. While the CF5 level frame, weighing approximately 965 g in size M (+/- 3% depending on the paint finish), and the CF5 level fork coming in at 457 g (+/- 3% depending on the paint finish) are considerably more complex in their carbon layup, the CF3 counterparts wheigh a little more but offer the same level of strength and stiffness. The CF3 frame comes in at 1145 g (painted, excl. axles) and the CF3 fork weighs 490 g (painted, uncut steerer tube, excl. axle). Another difference between the two frame levels is groupset compatibility as the CF5 frame is only compatible with electronic groupsets and the CF3 level frame allows for internal routing of both electronic and mechanical groupsets.

As with the REACTO III and the SCULTURA ENDURANCE, MERIDA are relying on specially developed aluminium heat sinks between the frame and flat-mount brake callipers for their latest aero bike. The so-called Disc Coolers are designed to reduce the risk of overheating the brakes, especially on long descents. While most modern high-performance disc brakes already have their own heat management systems, MERIDA see great benefits here, especially for lower-end brakes. The look of the heat sink is reflected in the Shimano Direct Mount derailleur hanger, keeping the design and look of the bike consistent.

The Shimano Direct Mount derailleur hanger reflects the design of the Disc Cooler on the front and rear

Geometry and components of MERIDA’s latest road bike

For the new REACTO, MERIDA have maintained the aggressive geometry of the previous model while making a few small changes. Henceforth, their aero bike will also be available with a XXS frame and the designation of the individual sizes will change. Previously, MERIDA used to designate intermediate sizes with “S/M” and “M/L” and hope to create more clarity with their new sizing model. The size M test bike was a good fit for our test riders ranging from 1.78 m to 1.84 m, providing an aggressive yet not too stretched riding position.

Thanks to the Flip Flop head of the seat post, you can fine tune the seating position to suit your personal preferences. Depending on what you like, you’ll be able to adjust the riding position to make it more compact or stretched using the stock components.

The geometry of the all-new REACTO

Seat tube 470 mm 500 mm 520 mm 540 mm 560 mm 590 mm
Top tube 520 mm 535 mm 545 mm 560 mm 575 mm 590 mm
Head tube 105 mm 112 mm 129 mm 141 mm 156 mm 176 mm
Head angle 70.5° 72.0° 72.5° 73.5° 73.5° 74.0°
Seat angle 74.5° 74.0° 74.0° 73.5° 73.0° 73.0°
Chainstay 408 mm 408 mm 408 mm 408 mm 408 mm 408 mm
BB Drop 70 mm 70 mm 66 mm 66 mm 66 mm 66 mm
Fork length 384 mm 384 mm 384 mm 384 mm 384 mm 384 mm
Stack 517 mm 529 mm 542 mm 557 mm 571 mm 592 mm
Reach 377 mm 384 mm 390 mm 395 mm 400 mm 409 mm
Wheelbase 985 mm 982 mm 989 mm 990 mm 1,000 mm 1,009 mm

For the launch of the bike, MERIDA are offering the REACTO in a total of 8 builds. The availability of the individual builds varies depending on your country or the corresponding dealership. The flagship models are the TEAM-E featuring a Shimano DURA-ACE Di2 groupset and Vision METRON 55 Clincher TL disc wheels for € 10,299, and the REACTO 9000-E with a SRAM RED eTap AXS groupset and DT Swiss ARC 1400 Dicut DB 50 wheels for € 10,799. Offering the best value for money are the REACTO 7000-E with a Shimano ULTEGRA Di2 groupset and DT Swiss P1800 Spline DB32 wheels for € 4,299, and the REACTO FORCE EDITION for € 4,799. However, the fully integrated Vision Metron 5D ACR cockpit is only available from the 8000 models and up. In Germany, the REACTO 5000 with a Shimano 105 groupset, Shimano RS 510 cranks and MERIDA EXPERT CW wheels is your lowest entry into the range at € 2,699. Internationally, you’ll be able to get the even more affordable REACTO 4000 with a complete 105 groupset and MERIDA EXPERT CW wheels, coming in at € 2,499. MERIDA rely on 700 x 25C tires across the board despite generous clearance for tires up to 30 mm wide. Our test bike, the TEAM-E, exudes true ProTour flair and even comes equipped with a dual-sided Shimano power meter. You’ll find the complete spec list below.

160 mm rotors front and rear
We were able to mount 700 x 32C Continental Grand Prix 5000 TL tires on the METRON 55 wheels and ride without any concerns about clearance and rubbing on the frame.

Groupset Shimano DURA-ACE R9150 Di2, 2 × 11, 52/36 t
Shimano CS-9100 cassette 11–30 t
Brakes Shimano DURA-ACE hydraulic disc BR-R9170 160/160 mm
Wheels METRON 55 Clincher TL Disc
Tires Continental Grand Prix 5000, 700 x 25C
Seat post S-FLEX carbon, integrated taillight and Flip Flop head, 0–20 mm offset
Handlebar Vision Metron 5D ACR Integrated, 420 mm
Stem Vision Metron 5D ACR Integrated, 110 mm
Weight 7.52 kg in size M
Price € 10,299
Availability from mid-August at your official dealer

Sporting the team’s new colours, the papaya of the REACTO TEAM-E pays tribute to McLaren’s proud heritage while the red and blue elements represent the national colours of the Kingdom of Bahrain. For our review, we had to make do with the Black Forest instead of Bahrain and Porsche instead of McLaren. The challenger probably doesn’t need much of an introduction: A 1977 Porsche 911 SC.

Motor 6-cylinder boxer, four-stroke, air-cooled, 2,993 cm³
Power output 132 kW (180 hp)
Transmission 5-speed, rear-wheel drive
Brakes Disc brakes (internally cooled) 282/290 mm
Wheels Fuchsfelgen 15 inch
Tires (f & r) TOYO 185/70 & 215/60
Weight 1,120 kg
Price from € 45,000
Available 1977: from Porsche dealers / today: second-hand market

MERIDA REACTO TEAM-E first ride review

Right from the get-go, the MERIDA feels very familiar. The decision not to make any changes to the geometry of the REACTO IV compared to the predecessor was an excellent choice on the part of MERIDA! Already on the REACTO III, we could hardly find weak points in terms of the riding position and handling. With a good mix of stability and agility, the bike allows you to navigate every corner with precision. It performs best through wide corners at high speed, feeling stable, holding its line and instilling the rider with confidence. Tight bends aren’t any problem either with the bike remaining easy to control, though it does need slightly more encouragement.

The bike’s overall comfort contributes to the feeling of stability and composure in the corners. The ergonomic cockpit and the cleverly designed seat post offer excellent vibration damping, and while the frame is quite stiff, it is by no means harsh. If you want to make the REACTO even more comfortable or plan on doing very long rides, you can take full advantage of the certified 30 mm tire clearance and fit significantly higher volume tires than the stock 700 x 25C Continental Grand Prix 5000. We were even able to mount 700 x 32C Continental Grand Prix 5000 TL tires on the METRON 55 wheels and ride without any concerns about clearance and rubbing on the frame. As such, there’s nothing to stop you from taking the shortcut over dirt roads or compact gravel or engaging in high-speed pursuits over cobblestones or rough asphalt. It’s remarkably versatile for such an aerodynamic high-performance bike! However, we have one small critique regarding composure and tracking stability: the front end is comparatively sensitive to crosswinds and needs to be kept on course by the rider.

Helmet POC Ventrail SPIN | Glasses 100% Speedcraft | Jersey GRAN FONDO x Cuore Custom | Shorts GRAN FONDO x Cuore Custom | Socks VOID Sock 16 | Shoes Specialized S-Works Vent

When accelerating, the MERIDA feels extremely direct and efficient, especially when sprinting out of a corner or slipstream – the perfect companion for the sprint on your home straight or the attack towards the finish line. On very steep climbs and when pulling away, it’s not the most light-footed, but that’s only if we were forced to find something to complain about. The REACTO climbs efficiently and performs just as well on the descents as on level terrain, allowing you to go fast and efficiently carry your momentum.

This is how we roll. #sharetheroad

REACTO vs. Porsche 911 SC

Chain on the right, indicator on the left. The DURA-ACE Di2 drivetrain clicks into gear as it shifts, the squealing tires of the Porsche echo through the valleys of the Black Forest and for a moment we become Marc Cavendish and Walter Röhrl. While it’s neck and neck in the first few meters, the MERIDA squeezes into the lead before the first corner. The rider’s lack of power is compensated with his skills in bike handling while the Porsche driver struggles finding the right gear. But on the final straight, the MERIDA rider’s legs give out and the Porsche pulls away on the inside. Ultimately, the race is clearly undecided! Our mini showdown comes to a conciliatory close with a champagne shower and after talking shop we evaluate the Strava segments. Three KOMs and a training intensity beyond good and evil.

Tuning tip: wider tires for an even more versatility (for both)

Both drivetrain concepts…
… are cooled by air.


MERIDA’s fourth-generation REACTO is a coherent and sensible evolution of their aero bike. It impressed us with its stability, excellent vibration damping and versatility for a bike of this kind! The only thing able to shake your confidence on it is a sudden crosswind, though not by much, allowing both pros and beginners to have the fastest and best time. An aerodynamic jack of all trades!


  • very composed
  • good vibration damping
  • all-round abilities
  • cable routing and level of integration


  • front end susceptible to crosswinds

For more information about MERIDA’s aero bike visit merida-bikes.com

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Words: Photos: Robin Schmitt, Valentin Rühl