Friday, June 17, 2016

Merida Reacto 4000: Part 1 - Introduction and Disassembly

Recently I had a chance to restore an aero road bike, the Merida Reacto 4000 as shown below. This is a road bike by Merida, and it is an aero road bike, which means a more aerodynamic frame and component placement, as compared to a conventional road bike such as the Merida Scultura.

The way that Merida uses to label their range of road bikes is quite straightforward, as I will explain here. Merida road bikes are generally classified into two main groups, Road Race and Road Comfort. Road Race consists of Scultura and Reacto, whereas Road Comfort has Ride and Ride Disc.

Road Race
Scultura - Conventional road bike looks with an emphasis on a lightweight frame
Reacto - TT style of bike frame design with an emphasis on aerodynamics

Road Comfort
Ride - Road bike with more relaxed geometry and extra damping from lower seat stay placement
Ride Disc - Basically the Ride with disc brakes

For each of these categories, the numbering signifies the type of frame material (aluminium or carbon), and also the grade of components used.

3 digit numbers (Eg. 400, 500) - Aluminium frame
4 digit numbers (Eg. 4000, 5000) - Carbon frame

One great thing I admire about Merida is that for their aluminium frames, they try to replicate the look of the carbon frame. For example, the aluminium Reacto 400 looks very similar to the carbon Reacto 4000 in terms of frame shape. Only upon closer examination is the aluminium welding visible.

The higher the number, the higher the grade of components used. For example, the Scultura 400 is an aluminium frame with Shimano 105 components, while the Scultura 5000 has a carbon frame with Ultegra components.

With this definition, it is easy to know roughly the type and grade of the Merida road bike just by looking at the model name and the model number.

The Merida Reacto 4000 is a road race bike with an aero shaped frame made of carbon, and is equipped with Shimano 105 components. I already have the Merida Scultura 5000 myself, and this bike was what my friend bought as a second hand bike from another seller.

Merida Reacto 4000 in stock condition

I went along to check out the condition of the bike, and found that it was in good condition. It was covered in a thick layer of dust, which means that the bike has been sitting in a storeroom for at least a few months. There is quite little wear and tear on the components, which means that this bike has seen very low mileage. After checking to make sure that there is no obvious damage on the frame or wheels, and that all the components are working fine, the deal was closed at a good price.

Before it can be used, I wanted to give the bike a full service, and also ensure that all the components are installed well and adjusted properly. It also gives me a chance to learn more about this bike and write about it.

Stock bike weight of 9 kg without pedals. This is a size 54 frame. Not lightweight.

Thick layer of dust on the Shimano 105 rear derailleur. Slight scratch marks on the RD which means the bike probably fell on its side before.

Dust covered Shimano 105 11 speed cassette and chain. Very little wear or dirt which means either very low mileage or very well maintained.

Dust is everywhere, including on the hub and also the spokes.

It comes with a FSA chain, and also has a quick link for easy chain connecting/disconnecting

Lots of dust also on the Shimano 105 front derailleur and bottom bracket area

Since this bike is so dusty, it will be necessary to disassemble most of the bike for a thorough cleaning of the components before reinstalling them. Time to start work!

Upon removing the rear derailleur, I took the chance to check the alignment of the RD hanger as it seemed that the bike had fallen on the right side before, potentially affecting the RD hanger alignment. Therefore, I decided to use a RD hanger alignment tool to check the alignment. For a detailed guide check out this link.

Using the RD hanger alignment tool to check and adjust the alignment of the RD hanger. It was actually quite well aligned, and not much adjustment was required.

After removing the front and rear wheels, I cleaned the dust off the hub and the spokes, but left the tires on as there is no need to remove them for cleaning. It is also a good chance to weigh these deep profile 38mm wheels.

Weight of rear wheel + tire + inner tube is 1680 grams.

Weight of front wheel + tire + inner tube is 1454 grams.

This gives a total wheelset weight (including 2 x inner tubes and 2 x tires) of 3134 grams. For comparison, the Ultegra 6800 wheelset on my Merida Scultura 5000 weighs about 2300 grams, which means a weight difference of more than 800 grams! This is a very significant weight difference for these aero wheels.

Merida Reacto stock wheelset with 38mm rims

Moving on, I continued the disassembly of the bike by removing the seat post and saddle. As usual, I took the chance to weigh the parts for future reference.

Wedge type of seat post locking mechanism, found recessed on the frame

Double chamber seat post tubing for the aero shaped seatpost. Not so nice surface finishing on the inside.

Rubber damper on the seat post for more comfort. Effectiveness is unknown.

Innovative seat rail design, with reversible clamps that can accommodate a round saddle rail or oval shaped carbon saddle rails.

Aero carbon seatpost weighs 291 grams. Considerably lightweight considering the chunky clamp design and the rubber damper.

Stock saddle on the Reacto 4000. Not lightweight, but looks good and is quite comfortable.

Current condition of the Merida Reacto 4000, with most parts disassembled for cleaning.

Disassembly is not completed yet, as I will still be removing the crankset for cleaning. To be continued!


  1. Hi, I have worn through the thread on the S Flex seat clamps. DO you have a suggestion on where I can buy new ones from?


    1. You can check with Hup Leong to see if they have spare parts.

  2. Just brought 2016 Merida Reacto form a guy in Brisbane covered in dust just a quick degrees did not pull apart looks like new, brought two armadillo tyres, happy when cork tape arrives, beautiful to look at blue and white two pivot brakes pulls up like a Porsche head turner. Why pay big bucks $1400.00 and hit the road.