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Rockrider AM Fifty_S 12-Speed Full Suspension All-Mountain Bike 27.5" - 29"

Sale price: $2,499.00 Regular price:

This version of our AM Fifty_S full-suspension mountain bike opens the door to official routes and technical trails, making it the most versatile bike in the all-mountain range.

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Sale price: $2,499.00 Regular price:

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About this item:

  • The full suspension aluminum bike with perfect travel to conquer your favorite trails
  • Rockshox Recon Silver 140 mm fork, Manitou Radium 140 mm shock
  • 12 speed Sram SX 12spd drivetrain/ Tubeless ready wheels
  • Hutchinson Toro tires: 27.5 x 2.25 in size S and M, and 29 x 2.10 in L and XL
  • Lifetime Warranty: frame, stem, and handlebars guaranteed for life
Model: 8787134

Product Videos

Product Features

A photo of the Rockrider AM Fifty_S 12-Speed Full Suspension All-Mountain Bike 27.5" - 29" in use
A photo of the Rockrider AM Fifty_S 12-Speed Full Suspension All-Mountain Bike 27.5" - 29" in use

Rockrider AM Fifty_S 12-Speed Full Suspension All-Mountain Bike 27.5" - 29" | This AM Fifty_S mountain bike has been designed for use on landscaped terrain and technical trails.

This version of our AM Fifty_S full-suspension mountain bike opens the door to official routes and technical trails, making it the most versatile bike in the all-mountain range.

Directional control

Steering control: 67° head angle, low bottom bracket, dropper seat post

Shock absorption

Rockshox Recon Silver 140 mm fork, Manitou Radium 140 mm shock

Braking power

SRAM Level brakes with dual-piston calipers and 180 mm / 160 mm discs.


Hutchinson Toro tires: 27.5 x 2.25 in size S and M, and 29 x 2.10 in L and XL

Questions & Answers

Product Customer Reviews

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Rockrider AM Fifty_S 12-Speed Full Suspension All-Mountain Bike 27.5
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The price is consistent with the quality, and for a weekend cyclist like me, it's perfect

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Good bike overall, but....

There are three problems with the passage of cables and housings: 1. The passage of the dropper cable (telescopic saddle) loops under the crankset, ready to catch roots and branches 2. The rear derailleur housing passes much too close from the chainring, a flex clamp is added to move it away but it is not enough, and on uneven terrain the sheath has already caught between the chain and the chainring. Temporary solution: add an iron wire between the crosspiece and the sheath to keep it away, and pass the sheath to the other side of the cable grommet. 3. Rear derailleur housing too tight at the cable grommets under the front of the frame. When the rear suspension is damped, the distance increases under the pivot point, if there is no pout it pulls on the derailleur housing junction which is very bad. Solution: add more pout (~4cm is enough) on the cable grommets and distribute this pout between the derailleur and the pivot point. In short: a bike which has potential with good value for money, but which has suffered premature wear due to very poor assembly of the sheaths. I don't know if the problem comes from the workshop that assembled the bike, or from the design itself. I hope that my comment will help to raise the problem, do not hesitate to contact me for clearer explanations.

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I recommend !

After purchasing this bike, I started my adventure in the world of full bikes, previously only hardtail. The bike is really very good. You can have something at an affordable price and fully enjoy the ride and the sensations it provides. The braking is good, the shock absorbers are also elegantly selected, 12 gears allow you to overcome the Krakowsko-Częstochowska Jura and it is an ideal terrain in which I feel best with this bike, uphill and downhill, hills and hills.

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Good product, easy to…

Good product, easy to handle (size S woman, 167cm, 47kg), light, I recommend this bike

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A great bike that…

A great bike that I was able to test just after my purchase on the GTMC with great pleasure: light for big climbs, super stable on descents on stones! A great option than the telescopic saddle, and appreciable suspension over long distances. The pleasure of mountain biking! I recommend

Excellent, I loved it

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When you see this bike on sale, do not hesitate to buy it because it has a very good price-quality ratio. The problem comes when when I arrived at the store, the box had a fairly noticeable dent, for which the guy who helped me solved it very quickly by asking me for another one. After waiting for the second bike I was finally able to enjoy it but not for long, since the changes started to go crazy and after going to the workshop more than 4 times in a row to adjust it there was no way to solve the problem so they told me For the second time the bike came defective and I had no choice but to ask for a refund... So right now I am very wary of buying a Rockrider due to the problems they may cause due to poor assembly or storage. Of course, I want to emphasize that the attention from both the staff in the cycling section and the workshop technicians was excellent.

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Very good bike, great value for money!

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About 300 km driven so far. Already tested in the field and great.

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Very good, well-equipped mountain bike

I bought this bike in size M equipped with a 27.5" wheel to replace my RR 9.1 26". The evolution of the geometry and the size of the wheels greatly contribute to the behavior of the bike, particularly in terms of dimensions. I also enjoy the descents a lot. Personally I bought it as a basic version for the upgrade later with a better fork and shock absorber. The small torque wrench provided is well thought out. Only small downsides: - no adjustment instructions for the shock absorber fitted as standard. - the screws that hold the shock absorber are rusty after 18 months of use, which is average for the perceived quality (I store my bike dry in my garage)



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The bike has a very strange set-up, it is heavy

It has a strange geometry, the front wheel loses its grip easily, the brakes are very "meh" after a few laps, if you press the brake hard for a few seconds, it brakes but does not offer a feeling of security, I hope that after I start grinding the pads again, it will recover . The tires that came with the bike were very heavy and besides that you said you were riding on cinder blocks on any terrain and they were very noisy. The fork does not work anywhere near as well as a rockshocks tora tk 29 on the spring I am extremely disappointed with the way it actually works it makes strange noises and works hard and the rebound is very noisy you say it doesn't have enough oil or something incorrectly mounted. The sheet is very small and is not at all suitable for a flat bike on the small sprocket, you cannot go over 17 km per hour no matter how hard you try with a cadence of over 100 and you have no chance of exceeding this speed. When climbing, it is absolutely horrible, regardless of whether you pedal on the saddle or in the drop, you feel the strange geometry instantly. The tubeless redy rim base on the rear wheel was mounted badly and I had to replace it to be able to fit tubeless tires. I went to the Decathlon Berceni store and there you don't have service in the true sense of the word, unfortunately the people there don't know and more importantly they don't have the tools to service brakes or forks or center a wheel. Honestly, I am very disappointed with the choices made by decathlon. When you opened the first military store, I was part of the team that actually set up the store and I was part of that team for almost 2 years in the bicycle and service district. And I had all the tools and all the necessary knowledge to do everything related to servicing a bike regardless of its range or complexity. The chosen direction is not correct, it is 100% wrong.

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AM 50 S


barely 400 km and broken bike

I bought Rockrider Am 50 S almost two years ago and I have barely used it, some short outings of a maximum of 20 km, now I have been riding on the roads of Tremp and Pobla de Segur for three weeks with a total of about 400 km accumulated doing outings of 20 At 30 km and suddenly I find the rear shock absorber loose with a screw hanging and the two frame supports bent. Impossible to reposition. I still can't explain what could have happened. The bike is now in the Barcelona workshops for review. What bothered me the most is that the guy at the Lleida workshop told me that this had happened to me due to poor maintenance, blaming me. The bike has not a single fall and is new, all the parts are original and look new. Now I don't trust this bike anymore. The luck is that I spend it on the flat and not going down paths.

Lack of documentation

Lack of documentation

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Size Guide

Size Guide Visual

Additional Product Information


Bike frame: 100.0% Aluminium

Which is the right size?

Several sizes available: S: 5 ft1 Inch to 5 ft5 InchM: between 5 ft5 Inch and 5 ft9 InchL: between 5 ft9 Inch and 6 ftXL: between 6 ft1 Inch and 6 ft5 InchIf you are on the edge between 2 sizes: Choose the smaller size for easier handling and comfort (straighter back).Choose the larger size for easier pedaling with a more stretched-out position (position more suited to higher performance).

How this mtb was designed

Entirely designed and developed in France at the B'Twin Village (Lille), this mountain bike is the fruit of the work of a team of experts and passionate all-mountain bikers who test the products in the Vosges and the Alps. The Rockrider team designed and tested this AM Fifty_S All-Mountain bike together with their MTB testers. The AM Fifty_S is assembled at our own factory in Lille, just steps away from the bike design team.


The Rockrider All Mountain frame offers 140 mm of travel on the rear wheel.Its geometry has been optimized for steering: 67° head angle, 15 mm bottom bracket under the wheel axle.Made of 6061 and 6013 aluminum.Lifetime warranty on the Switch & Ride frame: compatible with 27.5Inch and 29Inch wheels. 148 mm x 12 mm Boost rear axle.Press Fit 92 bottom bracket.31.6 mm diameter seat post.Compatible with a bottle cage.Weight in size S: 6 lbs.

Front suspension

Rockshox Recon fork with 140 mm travel.Compatible with 27.5 Inch and 29 Inch wheels and tires up to 2.8 Inch wide. It uses the boost standard for maximum control, fun, and comfort.The Recon fork has been designed with a tried-and-tested Motion Control cartridge, with low speed compression adjustment to lockout and external rebound adjustment.Fast Black steel finish on the dampers.Solo Air spring that takes just seconds to adjust, for a smooth, predictable ride.

Rear suspension

Manitou Radium 140 mm rear shock designed specifically for the Rockrider AM Fifty_S mountain bike.Adjustable to reduce bobbing during long climbs on faster terrain.


SRAM SX 12S 30 x 11-50 drivetrainSingle chainring for less weight, more precision, faster gear changes, and more durability.Rack: 30 teeth, easily replaceable (32 or 34-tooth chainring, available) without changing the chain. Cassette: SRAM Eagle in 11-50 (11-13-15-17-19-22-25-28-32-36-42-50). The 50-tooth sprocket guarantees good gear reduction to help you climb the steepest slopes.

Riding position

Control your steering and stay precise.RockRider Comp Flat handlebars, 740 mm wide for greater stability. 60 mm stem for a position that fts more suited to fast terrain Semi-integrated headset with sealed bearings. Lightweight RockRider 900 Inchlock on Inch grips (attached to the handlebar with a screw-on system).


SRAM Level brakes: The dual-piston brake caliper performs perfectly for all-mountain beginners and is a safe bet. 180 mm front disc, 160 mm rear disc.

Saddle and seat post

The RockRider XC/AM saddle has an Ergofit system for greater comfort while pedaling.The height of the dropper seat post can be adjusted using the control on the bike's handlebar: 120 mm of travel in size S/M and 150 mm in L/XL. The ability to lower the saddle in a second with a single press of the thumb is a real advantage in all-mountain biking. Feel at ease (and relaxed!) in your seating position on the bike during technical descents.

Product testing

Ask your local Decathlon store about testing before purchase.

Storage instructions

We recommend storing your mountain bike in a cool, dry place, away from corrosive products and salty air.


Lifetime (frame, stem, handlebar). Details on our website. Availability of spare parts: 2 years.



Ca warning

California Prop65 WARNING: This product can expose you to chemicals including Lead, which is known by the State of California to cause cancer. For more information, go to


Size Guide Visual

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