Free Delivery over £30* | Free Click & Collect at Decathlon Stores | 365 Days to Return
Reference : 8500761
Add to my wish list
Product already added

ROCKRIDER ST 540 S Full Suspension Mountain Bike - 27.5"

User rating
was £499.99 -%


This price includes a recycling fee for electrical equipment and batteries DecathlonDeeeTaxMentionAfterPrice / Since

From To

* Sales from to Until end of stock
* From and limited stock
£499.99 -%
This price includes a recycling fee for electrical equipment and batteries DecathlonDeeeTaxMentionAfterPrice / Since

* From To

* Sales from to Until end of stock
* From and limited stock
Check availability in store
This 27.5" MTB is designed for MTB rides lasting 2 to 3 hours, all year round. Control your trajectory even better with the fully suspended ST 540 S. 120mm fork, air shock, hydraulic brakes, and 27.5" double-walled wheels for guaranteed comfort with a sporty ride!
Not Available Now

Due to high demand, we are currently suspending online delivery for bikes. We are now increasing the availability of our bikes in our store showrooms while continuing with our Click and Collect service. This is a temporary measure and we thank you for your patience and understanding.

Product benefits

Cycling comfort Enjoy an upright position, adjustable stem, 120mm suspension and hammock saddle.
Directional control Control your trajectory: hydraulic fork and brakes, tyres and a wide handlebar.
Efficiency Ride efficiently with the 27.5" wheels, 18 speeds and light tyres.
Ease of use Lock the fork in one quick step, and adjust the saddle effortlessly.
Lifetime warranty ROCKRIDER offers a lifetime warranty on the frame, handlebars and stem.

Technical Information


Several sizes available:
M: between 1.65m and 1.74m
L: between 1.75m and 1.84m
XL: between 1.85 m and 2.00 m
If you are between 2 sizes:
Choose the smaller size for easier steering (easier to handle) and comfort (straighter back).
Choose the larger size for easier pedalling with a more stretched-out position (position more suited to performance).


The ST 540 S MTB has a UNISEX frame.
The ST 540's frame has been carefully designed down to the smallest detail, from the top tube's relatively pronounced slope, to the wide range of sizes (M: 1.65m to XL: 2m). The ST 540 S is not only lightweight and comfortable, but UNISEX as well.
To make the most of the improved comfort, the women on the Rockrider team recommend the 500 Women's Sports saddle, which is specially designed for the female form.


The ST 540 S mountain bike was fully designed and developed by our passionate MTB team at the B'Twin Village in France (Lille).
A comfortable, efficient mountain bike: more progressive and powerful hydraulic disc brakes, air shock and 120mm fork to get over obstacles easily, simple and effective double chainring.
Women mountain bikers have been involved at every stage of this bike's development process.


For less weight and more efficient pedalling, the Rockrider ST 540 S frame is made from 6061 aluminium (only 2.7 kg in size M without suspension). Its 120mm rear shock uses a single-pivot system (more sensitive to small impacts, while remaining firm when encountering large impacts) and sealed bearings for a great lifespan.


The hydraulic fork with 120 mm travel allows you to easily ride over more obstacles (roots, pebbles, stones, mud).
Steer a precise path with the higher diameter dampers (32 mm). The fork's built-in lockout system helps to prevent bobbing and loss of speed on faster terrain.


This bike has a light 120 mm X-FUSION E1 air shock that has been specially adapted to fit this frame. You can easily adjust it based on your weight using the Schrader valve, providing you with a very good balance of sensitivity and performance.
A special "high pressure" pump is required to adjust this shock (Rockrider fork and shock pump - ref: 3310286).


2 9-speed chainwheels for 18 easy-to-use speeds.
The thru-axle bottom bracket is very stiff and long-lasting.
In detail:
-SHIMANO Altus 22 and 36 tooth double chainring
-MICROSHIFT FD-M462 front derailleur
-SHIMANO Altus rear derailleur
-SHIMANO Acera shifters with speed indicators
-MICROSHIFT H092 9-cog 11 to 36 tooth cassette
-KMC X9 chain


The adjustable stem brings the ST 540 S controls to your hands. The all-aluminium Rockrider stem is 80 mm (size M/L), or 90 mm (size XL) and can be raised to 5 adjustment intervals: + 0mm, + 7.5mm, + 15mm, + 22.5mm, + 30mm.
In detail:
- 720mm oversize ROCKRIDER SPORT aluminium handlebar
- ROCKRIDER ergonomic grips for good grip and a comfortable feel.


Our teams designed and created an exclusive ROCKRIDER ERGOFIT Evo saddle. Designed for all hip widths, its hammock shape is very comfortable for long, athletic rides. The aluminium Rockrider Sport seat post is lightweight and has a wide adjustment range, with a 31.6 mm diameter and 400 mm in length.
Quick and easy tool-free adjustment of your saddle height using the adjustment lever on the seat post clamp.


No matter what conditions you ride in (dry/wet), the Rockrider by Tektro 160mm double hydraulic disc brakes will come through for you, even in the mud.
Hydraulic braking adds more power and progressive braking and requires less effort applied to the brake levers.
The aluminium brake levers are easy to grip, lightweight, and precise.


The aluminium wheels are effective and sturdy: 27.5" diameter and double-walled rims. Their diameter is the perfect balance between comfort and performance. With 28 spokes, they are lightweight, stiff, and durable.
The exclusive ROCKRIDER ALL CONDITIONS LIGHT 27.5"x2.1 60 TPI wide tyres have side knobs designed for riding on all types of terrain (dry, wet, etc.).
Tubeless Ready 23 mm rims: you will need rim tape, Schrader valves, and puncture sealant.


The ST 540 S comes with Rockrider Flat platform pedals with a wider pedalling surface and more pronounced dots for better grip on the pedals.


We added a quick release system for easily removing/reattaching the front wheel.
Tip: a bike rack is an easy way to transport your mountain bike without dirtying your car.


Your ST 540 S mountain bike comes with a bell, lights, wheel reflectors and pedals.
The frame is compatible with:
- Front and rear mudguards - bottle cage - saddle bag, etc.


Your bike's fittings (chain, derailleur, brakes, etc.) will adjust over time. Take advantage of a free servicing within 6 months after purchase. Our technicians will carry out a 13-point check of your bike. Just come to your nearest Decathlon workshop with your Decathlon card and/or receipt.


To ensure components last longer, we recommend a maximum load of 120 kg (rider and MTB included).


M - 165-174cm: 14.45 kg
L - 175-184cm: 14.55 kg
XL - 185-200cm: 14.65 kg
Weight without pedals.

See more See less

Composition / advice

100.00% Aluminium 6061
Stock advice After washing, rub with a dry cloth to remove all traces of moisture. Store your mountain bike in a cool, dry place, away from corrosive products and salty air.
Restricted use : Not suitable for XC, All Mountain, Enduro and BMX.
Legal notice To ensure components last longer, we recommend a maximum load of 120 kg (rider and MTB included).

Our commitments

Test Product Our engineers always have real riders test all our products in real conditions. These tests round out our lab tests and let us validate all our products before they hit store shelves.
Guarantee : Lifetime (frame, stem, handlebar). Availability of spare parts: 2 years.


Q : How to assemble your bike?
Everything you need to know about making sure your bike is comfortable, secure and ready to ride.
Q : How do you adjust your brakes?
Having properly functioning brakes is vital when out on the road. Check out how to get them working to your liking.
Q : How to replace a brake lever on a bike?
Having properly functioning brakes is vital when out on the road. Here’s a video to show you how to make sure your new brake level is working nicely.
Q : How to replace a disc brake?
Having issues with your disc brake? Then this video is for you.
Q : How to adjust your bike handlebar?
A suitable handlebar height is essential to your cycling safety and comfort. Find out how to adjust it to your liking with our video.
Q : Do you offer a Cycle To Work scheme?
Find out everything you need to know about way of getting to work that’s good you and the environment.Check Here

Your reviews

Reviews by our Team Members

Our services

ST 540 S Full Suspension Mountain Bike - 27.5
Maintenance and repair
Maintenance and repair
ST 540 S Full Suspension Mountain Bike - 27.5"
Because you look after your own health, we look after that of your products: tips for initial settings, maintenance and repair advice, video tutorials, FAQs, instructions...
See our tips Spare parts