ST 540 S 27.5" MOUNTAIN BIKE - RED

The ideal tyre pressure depends on the user's weight.

Basing the tyre pressure on the user's weight gives you the ideal balance between performance and resistance to pinching (if the inner tube gets pinched, it can lead to a puncture). If you want more grip, you can reduce the tyre pressure by 10%, but don't drop it below 2 bar as this will increase the risk of getting a puncture on rough ground.

To get your brakes in peak condition, you will need to bed them in. When your bike leaves the shop with its shiny new brake pads and discs, their braking power is very weak. You will need to do 10 sharp decelerations per brake to bed them in. By deceleration, we mean going quickly from 25 to 5 km/h, but without stopping the wheel from spinning, and using just one brake at a time.

Your ROCKRIDER 540 comes with a SUNTOUR XCR fork with two functions:

 

1/ Stiffness adjustment

 

Turn the dial clockwise to increase the stiffness, and anti-clockwise to decrease it.

 

2/ Lockout system

The lockout function stops the fork yo-yoing when you stand up or when you're climbing. The suspension isn't entirely shut off as there's still a little bit of travel. This is what stops you getting jolted. The system protects you on tricky terrain if you've forgotten to unlock the fork.

 

However, you should never leave your fork in lockout mode when riding on rough ground as the fork could get damaged if it is heavily compressed.

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. However, the wheel should never be buckled. If it is, we recommend using your free 6-month service at one of our Decathlon workshops to have any slight buckling corrected. 

There could be several reasons why your gears are not shifting smoothly or properly.   1- Check the position of the cable end caps   Poorly positioned cable end caps can disrupt the derailleur cable and stop the gears shifting properly at the back. If a cable end cap is out of place, use your hand to put it back in the right place.    2- The cable and housing might have seized up   If the gears are really struggling to shift onto the smaller chainrings, and the derailleur isn't moving even when you press the gear shifter, then the cable and housing are probably seized up. You will need to replace them. You can either visit one of our Decathlon workshops or replace them yourself with the help of this tutorial. 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 housing and cables more often.

There could be several reasons why your gears are not shifting smoothly or properly.   1- Check that the derailleur hanger isn't bent   If it is bent, the derailleur will be out of alignment and therefore won't be able to shift your gears correctly.  Stand behind your bike and look to see whether the derailleur is properly aligned (see image below) If the hanger is bent, visit a Decathlon workshop to have it replaced.   2- Check the positioning of the cable end caps   Poorly positioned cable end caps can disrupt the derailleur cable and stop the gears shifting properly at the back. For the rear derailleur, there are 4 cable end caps to check. If a cable end cap is out of place, use your hand to put it back in the right place.   3- The cable and housing may have seized up If you have a hard time shifting gears to the smallest cogs (the highest speed, since gears are numbered from largest to smallest), or the derailleur does not move even after pressing the gear shifter, the cable and housing have almost certainly seized up. You will need to replace them. You can either visit one of our Decathlon workshops or replace them yourself with the help of this tutorial. 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 housing and cables more often.

There are several reasons why a fork might feel very hard.   1- Adjustments   Visit the "adjusting your fork" section to easily adjust the stiffness to suit your preferences.   2- Basic maintenance   You should regularly lubricate your fork. A few drops of oil on the stanchions generally does the job.   3- Full maintenance   If adjusting your fork and performing some basic maintenance isn't enough, you should give your fork a more thorough service as shown in the video below.   Adjusting and maintaining your fork is done at your own risk. Decathlon cannot be held liable for any maintenance work you perform incorrectly. If you are not sure how to do any of the maintenance procedures, please visit your nearest Decathlon workshop.