B'Twin Rockrider ST 520 Mountain Bike

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B'Twin Rockrider ST 520 27.5" Hardtail Mountain Bike S, Black, 27.5" Wheels, Alloy Hardtail Frame, Disc Brakes, Altus & Microshift 24 Speed, weighs 14.35kg

Available in S in Black.

just £350!

View the B’Twin Rockrider ST 520 27.5″ Hardtail Mountain Bike

The Rockrider ST 520 Mountain Bike from Decathlon is an entry level hardtail featuring an alloy frame paired with an 80mm own brand suspension fork.

A 24 speed drivetrain comprising of a mixture of Altus & Microshift components powers the 27.5" in house wheelset, with black alloy components finishing off the build.

Essentially it's a more versatile (or cross-country) version of the ST 120, given the extra climbing gears and larger chainrings for faster descending.

Overall weight is a respectable 14.35kg (31.63lbs) given the low price tag.

B'Twin Rockrider ST 520 MTB

Pics of the ST 520
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  • B'TWIN Men's Alloy Hardtail MTB Frame with Front Suspension
  • Part of the range.
  • 27.5" Disc Brake Wheels
  • 24 Speed (Altus / Microshift Groupset - 3 x 8)
  • Available in S in Black.
  • Weighs 14.35kg
ST 520 Video Clips

Below are a couple of videos reviewing the ST 520. These weren't created by me, but should give you a better idea about the bike than words & pictures alone.


Full spec for the Rockrider ST 520

And here's the complete spec of the ST 520; this is all correct at time of publication, although obviously things can change due to availability of parts etc.

Frame & Fork
FrameComfort Geometry Frame (CGF); light aluminium frame
Forks80mm own brand suspension fork, weight adjustable using U-Fit technology
Frame MaterialAlloy
Frame TypeHardtail
Fork TypeSuspension Fork
Wheels
WheelsDouble-wall rims, own brand hubs
TyresFast Rolling DRY 27.5 x 2.0 tyres with semi slick central section
Wheel Diameter27.5"
Controls
Handlebars680mm oversize Rockrider SPORT aluminium handlebar
StemAluminium Rockrider stem is 70mm (size S), 80mm (size M / L), or 90mm (size XL) and can be raised in 5 adjustment intervals: + 0 mm, + 7.5 mm, + 15 mm, + 22.5 mm, + 30 mm.
HeadsetRockrider black headset
GripsRockrider Sport "soft touch" ergonomic grips
Finishing Kit
SeatpostFlex seat post, 350mm or 400mm long, 27.2mm diameter
SaddleRockrider Ergofit hammock saddle
PedalsFlat resin MTB pedals, compatible with toe clips
Braking
BrakesTektro TKD 68 160mm mechanical disc brakes
Brakes TypeDisc Brakes
Drivetrain
GroupsetAltus & Microshift
ChainsetRockrider FC ATB 500 triple chainring: 22 / 32 / 42 teeth
Front DerailleurShimano Altus front derailleur
Rear DerailleurMicroshift RD-M46-L rear derailleur
ShiftersMicroshift TS39 shifters front and rear
ChainKMC Z7 wide and sturdy chain
CassetteShimano 8-speed cassette with 11-32 range
Number of Gears24 Speed
ChainringsTriple Chainring
Cassette8 Speed
General Details
Bike TypeMountain Bikes
Range
Weight14.35kg
GenderMen's
Designed forMTB
ColourBlack
SizeS
BrandB'TWIN
RetailerDecathlon
RRP£349.99
Lowest Price£349.99

B'Twin Rockrider ST 520 Mountain Bike

This mountain bike has been designed and developed by us to best suit mountain-bike rides on hilly and rolling terrain.

With this bike you can go faster while controlling your trajectory. The mechanical disc brakes on the ST 520 mountain bike allow you to confidently take on descents, winding trails and obstacles.

Enjoy touring: raised position, 80 mm suspension, hammock saddle, FLEX seat post.

Control your trajectory: mechanical disc brakes, tyres with side knobs.

Smooth riding: light aluminium frame, 24 speeds and fast rolling tyres.

An ultra-strong MTB: welded saddle, double-wall rims.

Rockrider offers a lifetime warranty on the frame, handlebar and stem.

With a heavily sloped top tube and a wide range of sizes (from S: 1.50 m to XL: 2.00 m). The ST 520 mountain bike frame is UNISEX.

The ST 520 mountain bike is available with the same frame in a WOMEN'S version: fitted seat, narrower handlebar, shorter stem, fork with a more flexible spring, and brake levers that are closer together. As a WOMAN, if you choose the MEN'S model, we recommend at least purchasing the WOMEN'S SPORT 500 saddle which is fitted to the female form. Mountain bikers we talked to expressed their need for control so they can take more risks and continue to improve their technical skills.

With that as a starting point, we designed and tested the ST 520 mountain bike, involving MTB riders at every stage. Our designers created a frame that's easy to get onto. The CGF frame (Comfort Geometry Frame) EVO is made of 100% aluminium for greater comfort.

Its slope was carefully designed to keep your back straighter. The 80 mm front suspension helps you get started with overcoming obstacles on slightly uneven trails easily. Easily adjust the hardness using U-Fit technology (weight adjuster).

Simply set the number to your weight using the dial on the fork. This mountain bike has no rear suspension.

It is a "semi-stiff" mountain bike: perfect for beginners getting started with their first mountain bike rides.

Compared to a full suspension mountain bike (with rear suspension), it has the following advantages: the bike is lighter; you can pedal faster on flatter ground.

Derailleur & Drivetrain: 3 x 8 speeds, 24 speeds total! 2 shifters on the handlebar.

Left (chainrings): control ascents / descents.

Right (speeds): more precise control over your pedalling.

Rockrider FC ATB 500 triple chainring: 22 / 32 / 42 teeth. SHIMANO ALTUS front derailleur.

MICROSHIFT RD-M46-L rear derailleur. MICROSHIFT TS39 shifters. SHIMANO 8-speed cassette (11-32 teeth).

KMC Z7 wide and sturdy chain.

Handlebar, Stem, Grips: The adjustable stem on the ST 520 S allows you to position the levers so they're easy to grip.

The all-aluminium Rockrider stem is 70 mm (size S), 80 mm (size M / L), or 90 mm (size XL) and can be raised in 5 adjustment intervals: + 0 mm, + 7.5 mm, + 15 mm, + 22.5 mm, + 30 mm.

680 mm oversize Rockrider SPORT aluminium handlebar. Rockrider SPORT "soft touch" ergonomic grips for good grip and a comfortable feel.

Saddle: The ST 520 saddle is welded to prevent any saddle movement as you cycle.

Because your comfort is our top priority after your safety, we've added an exclusive Rockrider Ergofit saddle that is wider and hammock shaped. Easily adjust the height of your saddle with the Flex steel seat post (either 350 mm or 400 mm long, depending according to the bike size). Its reduced diameter (27.2 mm) provides your seat with natural flexibility, 30% more than a standard solution.

Mechanical Disc Brakes. The Tektro TKD 68 160 mm double disc brakes provide powerful, progressive braking at the front and rear. The aluminium Tektro brake levers are light, precise, and easy to hold.

You can brake with just two fingers. We recommend that you have your brakes checked at least once a year. 27.5" Wheels & Tyres For Dry Terrain.

The 27.5" wheels of the ST 520 are tolerant and sturdy, with 19 mm double-walled rims with 28 spokes. Fearlessly get started with riding over obstacles, small rocks, roots, holes and bumps! Because your first rides will be on dry terrain, the DRY 27.5 x 2.0 tyres are the most suitable. They have higher performance thanks to a smooth and fast central section, whilst the side lugs provide good grip on turns.

Platform Pedals. The Rockrider ST 520 mountain bike comes with flat mountain bike pedals made from hard resin for lighter weight and greater safety. If your feet can slide off the pedals when needed, there's less risk of injury.

The pedals on the ST 520 are compatible with toe clips.

Weight: 14.35 kg. Weight without pedals.

.. more details.

B'Twin Bikes

B'Twin Bikes

B'Twin are a popular choice of bike in the UK, partly due to their widespread distribution by Decathlon, and partly due to the value they offer. Their bikes are divided into several slightly overlapping ranges, with Triban best known for road and gravel bikes, and Rockrider gaining a reputation for high performing MTBs to suit every budget. Elops largely consist of a range of city bikes, whereas Riverside focus on hybrids. All in all, B'Twin bikes are well worth checking out given the size of their ranges; there's a model to suit most budgets.

Rockrider Mountain Bikes

Rockrider Mountain Bikes

Rockrider are Decathlon's off-road offerings, comprising of a series of kids bikes and adult hardtails, full suspension steeds and even a handful of high end E-MTBs.

This brand was launched in 2018, when Decathlon decided to split their B'Twin bikes into different genres. In terms of prices, there's something for everyone, with adult's MTBs starting at just over £200 and rising up to high end lightweight race bikes at nearly the £4000 mark.

If you want to ride off-road, and would prefer to buy from Decathlon, then the Rockrider mountain bike range is for you.

Rockrider ST 520 MTB Mountain Bike Specification

Bike TypeMountain Bikes
Range
Weight14.35kg
Frame MaterialAlloy
Frame TypeHardtail
Fork TypeSuspension Fork
Brakes TypeDisc Brakes
Number of Gears24 Speed
ChainringsTriple Chainring
Cassette8 Speed
GroupsetAltus, Microshift
Wheel Diameter27.5"
ColourBlack
SizeS
GenderMen's
Designed forMTB
BrandB'TWIN
RetailerDecathlon
RRP£349.99
Lowest Price£349.99

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