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This 27.5" mountain bike is designed for you to enjoy two- to three-hour rides all year round. Enjoy the comfort of the 120 mm front and rear suspension on this ST 530 S mountain bike. The single chainring and hydraulic disc brakes will have your back when dealing with uneven terrain.

First use

Inflating your tyres

The recommended average tyre pressure is 1.8 bar.If you're looking for more comfort and grip AND/OR if you weigh under 70kg, you can reduce the pressure by 10% but without dropping below 1.6 bar (the minimum recommended pressure). On abrasive terrain, however, this will increase the risk of punctures.You should check the pressure of your tyres regularly.


Adjusting the height of your handlebars

Your handlebar is set in the highest position to help keep your back raised, which is the most comfortable position for riding. For improved aerodynamics and more effective pedalling, you can lower your handlebars to lower your body. This will cause you to lean forward and adopt a racing position. Follow the steps in this video to move the headset spacers below the stem and lower the handlebars on your bike.


Aligning your handlebar


Adjusting the height of your saddle

Your bike's frame comes with a quick release system. Stand astride your bike. Undo the clamp by pulling its lever. Pull or push the saddle until it is at hip height. Tighten the clamp by pushing its lever back into place. For more precision, take a look at our video tutorial.


Adjusting the tilt of your saddle


Adjusting the stiffness of your fork

The BTWIN U-Fit fork has been designed to make adjusting it as easy as can be. A genuine innovation: weigh yourself and then turn the thumbwheel on the fork until your weight appears in the window. This will make the spring harder or softer, in line with your weight.


Bedding in your brakes

The brake pads and discs on a new bike are new themselves and don't work to their full potential.Hard, continuous braking (on descents, for example) can cause the pads to overheat and "glaze".To prevent this from happening and to ensure that your brakes slow you down effectively, we recommend that you bed them in.You need to apply each brake firmly around ten times to bed them in properly. The bedding-in process involves getting up to a speed of 25 km/h and then applying just one of the brakes firmly to reduce your speed to 5 km/h, without locking the wheel.

Positioning your brake levers


Changing your pedals


How to convert your wheels to tubeless

To reduce the risk of your inner tube getting perforated or pinched, you can convert your mountain bike's wheels to tubeless. To do this, you'll need to buy:   - A pair of TUBELESS tyres: DECATHLON: ALL TERRAIN 9 GRIP 27.5 x 2.10 TUBELESS READY/ETRTO 54-584 (8386245) MOUNTAIN BIKE TYRE - 21 mm rim tape:  ALLTRICKS: NOTUBES YELLOW 21 MM TAPE FOR 5 RIMS - A pair of Schrader TUBELESS valves: ALLTRICKS: NO FLATS JOE'S PAIR OF TUBELESS 36 MM SCHRADER (AUTO) VALVES - Puncture-prevention fluid: DECATHLON: SEALANT FOR TUBELESS READY TYRES AND RIMS (8550735)   WHAT TO DO:1. Remove the wheel2. Remove the original tyre and inner tube from the rim3. Apply the rim tape4. Poke the TUBELESS Schrader valve through the hole in the rim5. Add tyre sealant (to prevent punctures)6. Mount your new TUBELESS tyre7. Inflate the tyre quickly to seat it against the rimIf it all seems a bit tricky, feel free to contact your nearest DECATHLON workshop to get them to do it for you.

Adjusting your shock's hardness



The right equipment in case of a hiccup

If you're going to be able to deal with punctures, a broken chain or any other snag, you're going to need the right kit. Here's a selection of products that can get you out of various sticky situations. 

Have a problem?

The wheel is buckling

When you start using your new bike, lots of its parts are going to wriggle around as they settle into place.This includes your spokes, which might sound as if they're cracking due to the residual torsion from assembly.Your bike is equipped with double-walled rims (inside the wheels), which are sturdier than single-walled rims. Your wheels therefore shouldn't buckle.If they do, then please contact one of our Decathlon workshops to get them adjusted free of charge:1- As part of the free service we offer 6 months after buying your bike 2- If you have taken out the €1 breakdown insurance (valid for 2 years)Message for parents:Certain mountain bike tricks that are popular with kids (wheelies, skids, bunny hops, etc.) can lead to play in the rear hub and buckling in the wheels if they are repeated over and over. If your kids are doing these tricks often, it's important to make them aware of this problem.

wheelies and buckling of the ROCKRIDER ST 100 mountain bike's wheels

Unfortunately, anyone can get a puncture. - The ground (thorns, brambles, glass, nails, etc.)- And how you use your bike (taking on obstacles like rocks, steps, kerbs and potholes)are the most common cause of perforation punctures (small holes) and pinching punctures (small cracks close together), respectively.However, if you're getting a lot of punctures, it might be because of:- Incorrect wheel assembly in our factory, which has resulted in the end of a spoke piercing the inner tube- A faulty tyre or inner tube (porous)- A poorly repaired initial puncture that has left a foreign body (thorn, glass, metal splinter, etc.) in the rim or tyre.It is therefore important to correctly diagnose the puncture and remove any foreign bodies before carrying out the repair.Not sure how to remove/fit a tyre, or how to repair or change an inner tube?1- The simplest thing is to not even touch your wheel. Instead, get yourself out of trouble using a puncture repair spray: Screw the end of the tube onto your punctured tyre's valve (valve pointing down) and press and hold to inject the foam. The tyre should return to its initial shape and feel hard again so you can get yourself back home 2- If you have taken out our 1 euro breakdown insurance, you can then get your wheel fixed properly at one of our Decathlon workshops 3- To repair or change the inner tube yourself, take a look at our video tutorials below.  

ROCKRIDER ST 100 mountain bike puncture
The fork is too hard

There are several things you can do to soften your fork:1- Check the stiffness setting: see ADJUSTING YOUR FORK'S STIFFNESS2- Do some basic maintenance: your fork needs a regular dose of oil. Place several drops on the fork's steerer tube and move it around to work the oil into the blades.3- Take it to the workshop for a full service.


The back gears aren't shifting properly

There could be several reasons why your gears (sprockets) aren't shifting smoothly.1- Check the position of the cable end caps.Incorrectly positioned end caps can disrupt the pulling action on the derailleur cable and cause the shifting of the gears to be off. If either cable end cap is incorrectly positioned, put it back in place.2- Your cable and housing might be jammedIf you can't get down into the smallest year on your cogs, and the derailleur doesn't shift even when you move the gear shifter, then the cable and housing must be jammed. In this case, the cable and housing need to be replaced. Your local Decathlon workshop can assist you with this. Alternatively, watch this video to learn how to replace them yourself.3- Take your bike to a Decathlon workshop to get the derailleur adjusted 4- You might also want to check that the derailleur hanger isn't twisted. If it is, see "YOU'VE BROKEN YOUR DERAILLEUR HANGER"   NB: If you regularly ride your mountain bike in wet or muddy conditions, or if you regularly wash your bike with lots of water, then your cables and housing will need to be replaced more frequently. We strongly advise against washing your bike with a power washer as this can push dirt inside the housing. 


The brake lever is touching the handlebar too easily

If your brake lever feels spongy and/or touches the handlebar before your bike starts to slow down: You need to bleed your brakes. Visit one of our Decathlon workshops to get our technicians to do this for you.

You've broken your derailleur hanger

A bent hanger causes the derailleur to be out of alignment and therefore unable to function correctly. Stand behind your bike and examine the alignment of the derailleur.If the hanger is twisted or broken, visit a Decathlon workshop to have it replaced, or use this video to help you change it yourself.


You’ve broken your chain

Have you broken your chain? You've got 2 options: 1- Repair it yourself with the help of this video. You're going to need a chain tool and a quick link.  2- Visit one of our Decathlon workshops to get our technicians to repair it.


Maintaining your mountain bike

Cleaning your mountain bike

To clean your bike, you'll need a bike cleaner, a sponge and a brush.

First, hose your bike down.

Next, use the sponge and brush to apply the cleaning products.

Leave the cleaning products time to work, then rinse the bike.

Do this from a reasonable distance so as not to damage the mechanical parts.

Lastly, dry your bike with a soft, clean, dry cloth.


Cleaning and lubricating a drivetrain

To clean and lubricate your drive train, you will need a degreaser spray, a soft bristled brush and a lubricant.

The first step involves covering the brake disc with a clean cloth to prevent any lubricant from getting on to it.

Then apply the degreaser to the whole of the drive train and scrub the cassette, chain and derailleur jockey wheels with the brush.

Leave to act for a few minutes before rinsing the degreaser off from a suitable distance.

Allow the drive train to dry before applying the lubricant.

Shake the lubricant and apply to the inside of the chain, where it will work best. 


Changing a gear cable

Is your gear cable dirty, rusty or damaged, or are your gears hard to shift or shifting randomly? 

Then your gear cable needs to be changed! To do this, you'll need some pliers, a screwdriver, a cable cutter, an Allen key and a new set of cables and housing.

First of all, you'll need to remove the cable from its housing. Start by removing the plug from the shifter. Shift the gears all the way down, then cut the cable so you can pull it all the way out of the housing.

Next, hold the housing against your bike to work out how long it needs to be. Cut it and place the end caps on. You can now install the housing.

Pass the cable through the shifter and feed it through the housing. Next, screw the plug back in and fix the cable to the derailleur. Adjust the drivetrain by tightening the cable if the gears are struggling to shift up and slackening it if they are struggling to shift down.

Once you're done, cut the cable and use the pliers to crimp the end cap onto it.


Removing a rear wheel


Repairing a puncture

To repair a puncture, you'll need: a pump, a bowl of water, a cloth and a puncture repair kit.

Pump a little air into the inner tube. Locate the hole by submerging the tube in the water.

Once you've found the hole, dry the inner tube with the cloth and use the sandpaper in the repair kit to sand the tube.

This will enable the glue to stick better.

Apply the glue generously to the hole, and wait for 3 to 5 min.

Lastly, place the patch over the hole and press down for a few minutes.

You can then put your inner tube back into your tyre! 


Changing the derailleur hanger

To do this, you'll need a new derailleur hanger that's compatible with your bike (please check our "SPARE PARTS") and a 5 mm Allen key.

Remove the wheel and the damaged derailleur hanger.

Position the new hanger on the frame. 

Remove the piece of old hanger from the derailleur before putting the new one on using the 5 mm Allen key.

All that remains is to put the derailleur on the new hanger and check the gears.


Changing a chain

You will need the following: a chain tool, a new chain and a quick-release link.

Put the chain on the cog and on the smallest chainring. 

Remove the quick-release link using a quick-release chain tool and then remove the chain from the drive train.

Put the new chain on the last of the cogs and on the smallest chainring. This makes it easier to determine its optimal length.

The chain should pass close to the top pulley of the upper jockey wheel on the derailleur.

Once you've determined the length of the chain, use the chain tool to cut it as required.

Then fit the quick-release link on the chain and turn the pedal to position the quick-release lever on the top part of the chain. Press it with your hand to check that it is on the right position.


Changing hydraulic disc brake pads

You will need the following: new brake pads, a flat screwdriver and a 3mm Allen key.

Remove the wheel first of all. Then use the screwdriver to move the pads apart and put the pistons back into their original position.

Take out the pin holding the pads in place and remove them from their housings. Position the counter spring between the new pads.

Insert the new pads in the brake calliper and then put the pin back in place to complete the process.

Put the wheel back on and check to make sure that the brake pads are properly in place and do not rub against the disc.


Adjusting a hydraulic disc brake calliper

You will need a 5mm Allen key.

Unscrew the brake calliper, spin the wheel and operate the brake lever. It is important to keep the brake lever engaged before screwing the calliper back in place. 

Check to see that the disc and the pads are still in contact. 


Making sure the shock is tightened correctly and the hinge is in good condition


Compatible accessories

Mountain bike mudguard kit


mountain bike mudguard kit
500 Base stand

Fit the 500 BASE STAND to your ROCKRIDER ST 540

500 Black bike bottle cage



Spare parts

Go further

Need to change some parts? You'll find all our spare parts for the ST 530 S MOUNTAIN BIKE right here.



Our commitments

ROCKRIDER guarantees the frame, handlebar and stem of your mountain bike for life (in normal conditions of use).

The guarantee for other parts is two years.

As soon as your child starts using the bike, some components will move slightly. It's for that reason that we offer a free check of your mountain bike six months after purchase. 


Haven't been able to fix your problem or find what you need?

Please contact one of our technicians who will be happy to help