ROCKRIDER ST 540 MTB BLACK/RED

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.

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.

Your ST 540 bike frame is fitted with a quick-release lever.

Stand next to your saddle. Tilt the quick-release lever to unlock it. Pull the saddle up or push it down to bring it level with your pelvis.

Tilt the lever again to lock it.

To make sure you get it right, take a look at our tutorial video.

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.

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 ensure that your brakes perform, we recommend 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.

You can avoid the risk of the inner tubes on your mountain bike getting punctured or pinched by switching to TUBELESS.

To do this you'll need to buy the following:

 

- A pair of TUBELESS tyres:

DECATHLON: ALL TERRAIN 9 SPEED 27.5X2.10 TUBELESS READY MOUNTAIN BIKE TYRES / ETRTO 54-584 (8386245)

- 21mm rim tape: 

ALLTRICKS: NOTUBES YELLOW 21MM RIM TAPE FOR FIVE RIMS

- A pair of Schrader TUBELESS valves:

ALLTRICKS: PAIR OF NO FLATS JOE'S SCHRADER TUBELESS 36MM VALVES (AUTO)

- Sealant:

DECATHLON: TUBELESS READY TYRE AND WHEEL SEALANT (8550735)

 

STEPS TO FOLLOW:1. Take the wheel off.2. Remove the tyre and the inner tube from the wheel.3. Apply the tubeless rim tape.4. Insert a Schrader TUBELESS valve in the valve hole in the wheel.5. Apply the sealant.6. Fit your new TUBELESS tyre.7. You need to inflate the wheel quickly to ensure that the tyre sticks to the rim.If it seems too tricky, just visit your nearest DECATHLON workshop and ask them to do it for you.

When you take your new bike out for a ride for the first time, a lot of parts move around and fall into place.You'll hear the spokes on your wheels creak because of the residual torsion in them.Your bike is fitted with double-walled rims, which help make the wheels more solid. That means they should not buckle in any way at all.If they do, then call in at one of our DECATHLON workshops to have them repaired free of charge:1. As part of a free check-up in the first six months following the date of purchase. 2. As part of our €1 damage insurance plan (valid for two years).Message for parents:Young riders like to do tricks on their bikes (wheeling, skids, jumping off kerbs, etc). If done too often, however, they can cause play in the rear hub and buckle the wheels. If your child performs these tricks on a regular basis, speak to them and let them know the problems they can cause.

It's a sad fact of cycling that everyone gets punctures. - The terrain (thorns, bramble bushes, glass, nails, etc)- and use of the bike (catching tyres on obstacles such as stones, steps, kerbs and potholes)are the most common causes of punctures and pinched tyres respectively.If you keep suffering punctures, there can be several factors at play:- The wheel has not been assembled properly in the factory and a spoke keeps piercing the inner tube.- A substandard tyre or inner tube.- A badly repaired puncture or a foreign body (thorn, piece of glass, shard of metal, etc) stuck on the rim or in the tyre.It's important to find out what is causing the puncture and to remove any foreign bodies before repairing it.I don't know how to put a tyre on or take one off so how am I going to repair or change an inner tube?1. The simplest thing to do is not to touch your wheel and use a can of puncture repair foam as a temporary solution: Screw the end of the tube on to the valve of the punctured tyre (with the valve pointing down) and press down to inject the foam. The tyre will regain its shape and hardness, allowing you to get home. 2. If you've taken out our 1-euro damage insurance plan, you can have your tyre fixed at one of our DECATHLON workshops. 3. If you want to repair or change the inner tube yourself, then check out the tutorial videos below.  

There are one or two things you can do to make your fork "softer":1. Adjust the stiffness: check the section "ADJUSTING THE STIFFNESS OF YOUR FORK"2. Do some basic maintenance: using a simple oil can. Squirt some oil on the pivots of the fork and move it around to work the oil into the blades.3. Have the bike fully serviced in a workshop.

There could be several reasons why your gears (chainrings) are not shifting correctly.1. Check the position of the housing ends.Housing ends that are out of position can obstruct the derailleur cable when it is being pulled and prevent the gears (chainrings) from shifting smoothly. If a housing end is out of position, push it back into place.2. The cable and housings may have jammed up.If the smallest gears (chainrings) do not move down, if the derailleur doesn't move even when the gear shifter is operated, then the cable and the housings have jammed up. They need to be replaced. Take your mountain bike to a DECATHLON workshop or replace them yourself with the help of this video.NB: If you regularly use your mountain bike in wet or muddy conditions or if you wash it a lot, then you will need to replace the housings and cables more often. We strongly advise you not to use a pressure hose to wash your mountain bike as it will force dirt into the housings.

There could be several reasons why your gears (cogs) are not shifting correctly.1. Check the position of the housing ends.Housing ends that are out of position can obstruct the derailleur cable when it is being pulled and prevent the rear gears (cogs) from shifting smoothly. If a housing end is out of position, push it back into place.2. The cable and housings may have jammed up.If the smallest gears (cogs) do not move down, if the derailleur doesn't move even when the gear shifter is operated, then the cable and the housings have jammed up. They need to be replaced. Take your mountain bike to a DECATHLON workshop or replace them yourself with the help of this video.3. Take your mountain bike to a DECATHLON workshop to have the derailleur adjusted. 4. You should also check that the derailleur dropout is not twisted. If it is, check the section "YOUR DERAILLEUR DROPOUT IS BROKEN".   NB: If you regularly use your mountain bike in wet or muddy conditions or if you wash it a lot, then you will need to replace the housings and cables more often. We strongly advise you not to use a pressure hose to wash your mountain bike as it will force dirt into the housings. 

The lever is spongy and/or touches the handlebars before you can brake:You need to bleed the brake system.Drop in at a DECATHLON workshop and get one of our technicians to do it.

A twisted dropout causes the derailleur to become misaligned, preventing it from doing its job correctly. Look at your bike from behind and check to see if the derailleur is straight.If the dropout is twisted or broken, take your bike to a DECATHLON workshop to have it replaced. Alternatively, watch this video. It will show you how to replace it yourself.

So you've broken your chain.You've got two options: 1. Repair it yourself with the help of this video. You'll need a chain tool and a quick-release link.  2. Drop in at one of our DECATHLON workshops and have it done by one of our technicians.

To clean your bike properly, you'll need some bike cleaner, a sponge and a brush. Spray the bike with a hose before applying the cleaning products. Use the sponge and brush to apply the products. Allow the product to act before rinsing the bike. Rinse it from a distance to avoid damaging mechanical parts. Finally, dry the bike with a soft, clean, dry cloth.

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. 

Is your drive train cable dirty, rusty or damaged or are your gear changes stiff, random or not as slick as they should be?  If so, the cable needs changing.You'll need a pair of pliers, a screwdriver, cable cutters, an Allen key and a new derailleur cables and housings kit. Start by removing the cable from the housing. Remove the hood from the gear shifter, move the indicator to the last gear and cut the cable. This will allow you to remove all of the cable and then the housing. Cut the housing to size and fit the end caps on the end of the cable, which is now ready to fit. Thread the cable through the shifter and push it through the housing. Then put the hood back on the shifter and attach the cable to the derailleur. To adjust the drive train, tighten the cable if the gears do not shift up easily and slacken it if they do not shift down smoothly. Finally, cut the cable and use the pliers to attach the end cap to it.

You need the following to repair a puncture: a pump, a basin of water, a cloth and an inner tube kit. Put a little pressure on the inner tube. To find the puncture, submerge the inner tube in the basin of water. Once you've spotted it, dry the inner tube with a cloth and scrape the area around it with the sandpaper provided in the kit. Scraping the inner tube will allow the glue to adhere better. Apply the glue generously around the hole and wait for three to five minutes. Place the patch over the hole and hold it there for a few minutes. You can then fit your inner tube back into the tyre.

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 caliper 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.

You will need a 5mm Allen key. Unscrew the brake caliper, spin the wheel and operate the brake lever. It is important to keep the brake lever engaged before screwing the caliper back in place.  Check to see that the disc and the pads are still in contact. 

You will need a new derailleur dropout that fits your bike (check the "SPARE PARTS" section) and a 5mm Allen key. Take off the wheel and the damaged derailleur dropout. Position the new dropout on the frame.  Remove the old dropout part from the derailleur before fitting the new one with the Allen key. Fit the derailleur on to the new dropout and check the gears.