" />

ST 520 27.5" Mountain Bike - Black/Blue

8350582

ROCKRIDER

Made for


Comfort first and foremost: hollow saddle, frame geometry, adjustable stem. And enjoy the effectiveness of the 27.5" wheels with double-wall rims and 24 speeds. The benefits: mechanical disc brakes.

Sizes guide

This product is no longer in stock

Buy
     In-Store

view all stores

Advantages
Cycling comfortEnjoy the raised position, adjustable stem, 80mm suspension and hollow saddle
Directional controlControl your path with the double disc brakes and notched tyres.
EfficiencyEfficient cycling thanks to the 27.5" wheels, 24 speeds and aluminium frame.
Ease of useUse the wheel to adjust the fork to your weight. Easily adjust the saddle.
Lifetime warrantyRockrider provides a lifetime guarantee for the frame, stem and handlebars.
WarrantyLifetime (frame, stem, handlebars). Availability of spare parts: 2 years.
Technical Information

1
WHAT OUR TEAM HAS TO SAY
This ST 520 mountain bike has been entirely designed and developed at the B'Twin Village in France (Lillle). We've designed, developed and tested the ST 520 MTB for comfort and efficiency. This combines to give MTBers confidence to overcome any new obstacle. We have involved real MTBers at every stage of this bike's design process. And we hope that the Rockrider ST 520 is everything you could hope for to give you excellent MTB rides.
2
A UNISEX MOUNTAIN BIKE
Men's or women's mountain bike? This Rockrider ST 520 mountain bike is unisex. For greater comfort, the women on our mountain bike team recommend replacing the saddle with the Women's 500 Sport saddle, which is adapted to women's bodies. A range of Rockrider mountain bikes specifically designed to fit female morphology is also available (specialised saddle, stem, fork and brake grips).
3
HOW TO CHOOSE YOUR ST 520 MOUNTAIN BIKE SIZE
Several sizes available: S: between 1.50m and 1.64m 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 on the limit 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).
4
A COMFORTABLE, PLAYFUL FRAME
For a lighter weight and more efficient pedalling, the Rockrider ST 520 frame has been designed with 6061 aluminium (only 1.9 kg in size M). Our designers have designed and developed it so it is comfortable and easy to manoeuvre. Its slope has been designed to keep your back straighter. The lower bottom bracket helps keep you more stable during turns.
5
FRONT SUSPENSION TO CUSHION UNPREDICTABLE TERRAIN
Directly adjust the stiffness of the suspension to your weight, to more easily travel over roots and stones. The 80 mm front suspension is designed for slightly uneven trails and helps you overcome your obstacles with no worries. It is based on a mechanical spring and is reliable. And it's easy to look after.
6
REAR SUSPENSION: NONE
This mountain bike has no rear suspension. This is a "semi-rigid" mountain bike. Compared to a full suspension mountain bike (with rear suspension), the advantages are clear: lighter weight, you will spend less energy on flat ground. However, if you want more comfort, the ST 520 MTB also exists in a "full suspension" version with a rear shock absorber.
7
DERAILLEUR & DRIVE TRAIN: HOW TO CHANGE SPEEDS
3 8-speed chainwheels, or a wide range of 24 speeds. 2 quick shifters on the handlebar. Left (chainwheels): control ascents/descents. Right (speeds): more precise control over your pedalling. In detail: - Triple chainwheels - 22, 32 and 42 teeth - SHIMANO Altus or MICROSHIFT FD-M22 front derailleur - SRAM X3 rear derailleur - SRAM X4 shifters, with speed indicators - SRAM PG820 8 cog cassette, 11 to 32 teeth
8
HANDLEBAR, STEM, GRIPS: TAKE CONTROL OF THE HANDLEBARS
With its adjustable stem, the ST 520 controls are close at hand. The all-aluminium B'Twin stem is 70 mm (size S), 80 mm (size M/L), or 90 mm (size XL) and can be raised using 5 adjustment intervals: + 0mm, + 7.5mm, + 15mm, + 22.5mm, + 30mm. In detail: - 680mm oversized aluminium handlebars - Soft touch B'Twin sport grips for good grip and a comfortable feel.
9
SADDLE / SEAT POST: COMFORTABLE AND SPORTY SEAT
Our teams conceived and designed an exclusive saddle for this bike. Suitable for different hip sizes, its "hammock" shape is particularly good for sport touring. The Flex 27.2mm diameter aluminium seatpost also contributes to its increased level of comfort. Quick and easy tool-free adjustment of your saddle height using the adjustment lever on the seat post clamp.
10
MECHANICAL DISC BRAKES: GET A GRIP ON YOUR BRAKING
The HAYES M-X5 mechanical double disc brakes give you gradual, powerful braking at the front and back. Whilst the aluminium Tektro brake levers are light, precise, and easy to hold. Just two fingers are all you need to brake. Try to get your brakes adjusted at least once a year.
11
27.5" DOUBLE-WALLED WHEELS & TYRES FOR DRY GROUND
Take on obstacles! The aluminium wheels are effective and sturdy: 27.5" double-walled rims. Their diameter is the perfect balance between comfort and performance. With their 28 spokes, they are lightweight, stiff, and durable.The exclusive 27.5" x 2.0 B'TWIN ALL TERRAIN DRY tyres are designed for dry terrain. Their side lugs provide good traction during turns. The recommended tyre pressure according to the weight of the rider is marked on the tyre sidewall.
12
PLATFORM PEDALS
The ST 520 is supplied with platform MTB pedals mounted on bearings, made from resin for light weight and safety. If your foot slides on the pedal, there's less risk of injury.
13
EASILY TRANSPORT AND STORE YOUR MOUNTAIN BIKE
Not all rides start on your doorstep. Need to remove the front wheel? It's easy thanks to the integrated clamping lever. And the rear wheel? There is a nut at the back to secure the bike and limit the risk of theft. A flat spanner is needed to remove the rear wheel. A bike carrier will make your life easier if you want to avoid dirtying your car.
14
ACCESSORIES
Your ST 520 mountain bike is supplied with a bell, lights, wheel reflectors and pedals. The frame is compatible with: - front and rear mudguards, - stand, - bottle cage, - saddle bag, - rear pannier rack, - child seat (add an additional pannier rack for sizes S and M to avoid touching the rear wheel) etc.
15
OUR ADVICE FOR YOUR FIRST FEW RIDES
Tip No.1 When mountain biking, there is always the risk of a fall: don't forget to wear a helmet. Tip No.2 Even if the saddle is comfortable, cycling shorts with a pad (saddle-shaped foam) are a real plus for preventing glute pain. Tip no.3 If you don't want to stop to drink, bring water in a bottle or water bladder to access it while riding. Tip No.4 Punctures are always possible, remember to bring a repair kit.
Information / Concept / Technology
Composition
Frame (for bike) : 100.0% Aluminium 6061

Product test
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.

Stockage tips
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.

Reviews

Sort by:
Great bike love it
Used for More than 2 years
Bought one of these 3 years ago and love it. Admittedly I'm not using it as a mountain bike instead I've put some 1.5 road tyres on it, mud guards, pannier rack mirrors etc and use it as a touring bike. So far I've done over 3000 miles on the bike including an 800 mile 8 day tour from Switzerland to the Hook of Holland. Had a couple of issues the axle worked loose on the back wheel causing a woble and the derailleur to jump gears but got it sorted in store over 1500 miles ago and still OK. Recently developed a but lateral movement in the bottom bracket which is being looked at now. But considering the mileage I think we can put that down to fair wear and tear, and a new bottem bracket fitted is less than £40,
Excellent bike for the money
Used for 2 to 8 weeks
Good modern geometry solid bit lightweight good commute and trail bike highly recommend
Bike
Used for 2 to 8 weeks
Great bike i Cycle regular mainly on the road can’t complain thus far
Great piece of kit I have bought 3 of these.
Used for 7 to 12 months
Great piece of kit I have bought 3 of these !
Gear stopped to work
Used for 2 to 8 weeks
1st the bike seemed okay. But then later I realized that it was nearly impossible to get it to 3rd gear. Changing gears is often really hard as it gets stuck. Today when riding the bike I changed from 2nd to 1st gear, the chain fell off from the bike and as I was surprised I nearly crashed into a car. I try to quickly fix it on the side of the road by putting it back to the proper place. It worked for 10 minutes, but then I realized that whenever I try to change to any other gear some parts of the front gear shift blocks the tire hence it does not rotate. I called my nearest Decathlon where they told me that my only option is to go there. This means that I will have to walk 2 hours. For a bike that I used for around 20 hours so far. I will demand a full refund and never buy at Decathlon again.
Response of the brand
Dear Sir,
Thank you for taking the time to review your bike. As with many new bikes, the gear cables can stretch a little and for this reason we offer free checkups for customers in store within the first three months. This irons out any adjustment issues to be sure you have many miles of smooth riding ahead. Your local workshop will discuss this with you directly.
Regards,
Peter, Cycling Manager, DECATHLON
Stunning Bike Comfy Ride
Used for 1 week or less
Comfortable Bike great value for first mountain bike smooth gear change
Decent bike
Used for More than 2 years
2nd time buying this bike, really smooth, however at the start some visits to decathlon are needed in order to tackle some noises and some problems with the chain, but they manage to fix them appropriately & after that it’s a pleasure to ride, would highly recommend
Bike colour
I was a bit annoyed to find their was a black one just not listed with the other colours so instead I bought the grey one but it would have been better if you listed all the colours with the actual bike not seperate
Very satisfied.
Used for 3 to 6 months
I bought this bike 6 months ago in Hannover. It was marked as set up and ready to ride although a few minor adjustments were required. The front mech was only shifting into 2 sprockets but i am a mechanical guy so sorting that out is not an problem. Anyhoo, i have done 1,400 Km since then and not a single mechanical issue. Even though i have crashed it heavily a coule of times. The rear tyre wore out after 1,000 k otherwise its fine. Thats about 80% road 20% forest track. I have looked after it and kept it well maintained, should last a few years. The tyres are the weak point on this bike. I suggest changing them out for better wuality ones.
Hugely disappointing
Used for More than 1 year
Poor, and I’m usually a fan of Decathlon. Absolutely atrocious courier service (BJSDelivery), the worst I have ever encountered, and the bike I ordered came incorrectly set up. Fortunately, I know enough to remedy but if I’d have got on it without re-aligning front mech, and other things, it’d have been a death trap. Expect a trip to your local bike shop. The courier experience (delays, lies, laughably inept people who ‘could not deliver in the dark’, or reverse their van, or....etc etc) is reason enough to avoid. A cost cut too far for Decathlon. Huge shame.
Response of the brand
I'm sorry to read that the courier service was not good enough. I have forwarded your comments on to the team who manage this account to take it up with them. I have also forwarded your feedback regarding the set up to the bike building team in the warehouse.
Regards,
Peter, Cycling Manager, DECATHLON
Show results for