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Hydraulic disc brakes: Greater efficiency

All Bikes Cycling - Rockrider 520 Mountain Bike B'TWIN - Bikes
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B'TWIN Rockrider 520 Mountain Bike

Intensive mountain biking.

To view our full range visit our mountain bikes category.


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until £330.00 - %

From £330.00**

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Price in store £0.00 £330.00 **

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Free delivery with Click & Collect
From : 09/10/2015 with this item
Reference : 8293188

Delivery Info: When buying a bike online, pedals are not fitted and the stem/bars are not adjusted. View this video to see how to correctly set up your bike at home.

Our customers pictures

Product benefits

    • User comfort
    • Raised position. Ribbed grips. Covered saddle. 100 mm fork.
    • Efficiency
    • Double hydraulic disc brakes. Forks with lockout feature. 27-speed SHIMANO.
    • Ease
    • Lock your fork by hand in an instant.
    • Lifetime warranty
    • B’TWIN guarantees the frame, stem and handlebars for life.
    • Precision
    • HUTCHINSON Python tyres: A golden standard in grip and performance.
  1. Guarantee : Frame, handlebars and stem have a lifetime warranty. 2-year warranty for parts (excl. wearing parts)

Product information

S: 150-165; M: 165-175; L: 175-180; XL: 180-195
Black / White / Red
Wheel size
26 inches
Suspension fork
13.4 kg in S without pedals

your reviews

4.4 / 5

36 reviews

33 people recommend this product

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The chain has many problems

Chain slips and can't use all gears!


  (United Kingdom)

40-49 years old    Man

2 5

used for 2 to 8 weeks Ive had the rock rider 520 for a few months now. Ever since I got the bike more and more problems occur. In the shop the bike is prefect but once it's out and being used his hills the chain slips causing my to slip off twice.
The bike chain only slips on hills really it's happened around 50 times now and I've found the bike to be getting worse.
Getting onto the next problem. The gears down all work. I've been in to see you 3-4 times now and it works prefect in the shop as the previous problem then it doesn't once home riding. Each time I've been in you have looked at it and spent 4-5 hours messing around with it then sending me home which isn't right because I payed for a quality bike and service and I'm not getting it. I Want this problem fixing or a upgrade to the next bike being as this is unacceptable!

Response of the brand

Dear sir,
I'm sorry to read that you're experiencing regular issues with your Shimano Acera gears.
So many things can affect the quality of the shifting. It may be best that we strip down your drivetrain and start again or provide you with a new bike. There is no reason why your local store can't do this for you.
Here is an interesting article on the subject:
Please contact your local store and we can arrange to find a solution which suits you best.
Peter Lazarus UK Cycling Market Manager DECATHLON

Rockrider 520

Look/weight/quality/performance/delivery ect ect



  (United Kingdom)

40-49 years old    Man

5 5

used for 3 to 6 months WOW I have bought a few bikes over the years and this is miles ahead in quality! The look is epic .a real head turner:) the delivery was super fast and friendly van man ) the gears were all set up all I had to do was lift it out or the box and attach the handlebars took 2 mins and it was ready to rumble :O) I am so happy with this purchase best investment ever >>> looking forward to many miles in style 110% reccomended

Rockrider 520 Mountain Bike

Everything about the bike is ecellent.

Nothing disappointed me about the bike.


  (United Kingdom)

40-49 years old    Man

5 5

used for 2 to 8 weeks Very good price for the quality and build of the bike. Took a few goes to get use to sharp hydraulic brakes, but no problems now. Very happy customer.

Please read if you are buying a rock rider 520mtb

Gears and chain slip


  (United Kingdom)

30-39 years old    Man

2 5

used for 3 to 6 months This is the second bike of the same make from the same place that I have had problems with, the first time it was with the slipping of gears and with the noise from the chain witch I was told was my fault because of the way I changed the gears, but if I pay for 27 gears surly I should get to use all of them, but to be fair they could not fix the slipping of the gears and replaced the bike but this was after 4 visits and keeping in mind I'm a 130 mile round trip
So this time I have the same problem with the chain noise and a slight slip in the gears but I'm just going to wait for my free three month service and if they carnt fix it or hit out with some silly reason then I will be getting in contact with trading standards and will be expecting a full refund so that I can go and get a bike I can use because at the moment it sits in my kitchen not get used as I have lost all faith in btwin bike and decalthon

Response of the brand

Dear Sir,
Thank you for taking the time to give us a review of your bike. I'm sorry to read that the gears have not worked as well as expected.  We have fitted the Shimano Acera drievetrain on this bike.
I have asked the store to contact you directly to try to get you out enjoying your bike as quickly as possible.
Our apologies for the annoyance this has caused.
Peter Lazarus UK Cycling Market Manager DECATHLON

Stephen found this review helpful

nice bike

good price for this bike and good quality

3th and 4th gear change not very smooth for mine


  (United Kingdom)

30-39 years old    Man

4 5

used for 1 week or less good price and quality for this rockrider 520.

Technical Information

  • 1

    Frame B'TWIN SPORT MTB frame, in strengthened 6061 aluminium.
    Sports geometry, perfect for intensive touring.

  • 2

    Fork Rockrider XCR 100 mm lockout fork by SR Suntour.
    Lightweight and durable hydraulic fork cartridge.
    Preload adjuster and lockout.
    100 mm travel.
    Magnesium fork blades.
    The damper finish ensures a long lifetime.

  • 3

    Suspension No rear suspension.

  • 4

    Drive train MIRANDA BETA BLACK aluminium 22x32x42 crankset;
    Shimano X50 or Microshift M30 front derailleur;
    Shimano ACERA rear derailleur;
    Shimano ACERA 9-speed shifters;
    SRAM PC951 chain;
    PG950 9-speed 11 x 32 cassette.

  • 5

    Brakes AURIGA Comp 160 mm hydraulic disc brakes at the front and rear for greater braking power and precision, even in extreme conditions (e.g. mud).

  • 6

    Handlebars Rockrider SPORT oversized handlebars: oversized diameter for greater stiffness and more accurate steering.
    Width from 600 mm (S) to 640 mm (M, L and XL).

  • 7

    Stem Oversized Rockrider SPORT stem (oversized diameter), with a 6° rise. Length: 90 mm (S), 100 mm (M) and 110 mm (L and XL).

  • 8

    Steering Aheadset Rockrider SPORT headset, 1⅛".

  • 9

    Saddle Rockrider SPORT LIGHT saddle.

  • 10

    Seat post Rockrider SPORT seat post: diameter 29.8 mm, length 350 mm.

  • 11

    Wheels RIGIDA SPHINX 32-hole, double-walled rims.
    Watertight Formula DC19/DC22 disk ready hubs,
    2 mm diameter stainless steel spokes: impact and corrosion-resistant.

  • 12

    Tyres Hutchinson Python tyres with versatile profile: a market benchmark.

  • 13

    Pedals Wellgo MTB platform pedals with toe-clip for holding the foot firmly in place.

  • 14

    Accessories Possibility to add accessories (bottle cage, mudguards, bag under the saddle, pannier rack at the rear, etc.).

  • 15

    Weight 13.4 kg in size S without pedals.

  • 16

    Electric assistance No electric assistance.

Information / Concept / Technology

Stock advice

Store in a cool, dry place, away from corrosive products and salty air.

Care instructions:

Grease your chain regularly and check your tyre pressure often (recommended before each outing). Check your hosing every three months and ensure screws and nuts are tightened properly.

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