ROCKRIDER 520 27.5" MOUNTAIN BIKE - NAVY BLUE

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. The brake pads and discs on a new bike are new themselves and don't work to their full potential.

 

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. Do this 10 times per brake.

Your ROCKRIDER 520 will have one of two different forks.

 

They are adjusted as follows:

1/ SUNTOUR XCT fork

 

If your fork has two preload knobs, be aware that they work completely independently. Use the first one to adjust the preload and, if the preload level isn't right after you've turned it all the way, use the second knob. Turn it clockwise to increase the fork's stiffness, and anti-clockwise to make the fork softer.

 

2/ BTWIN U-Fit fork. The U-Fit fork has been designed to be as easy as possible to adjust. Turn the dial until you see your weight indicated on the back of the fork. Turning the dial increases or decreases the compression of the spring to adjust it to your weight. That's innovation!

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 wheel should not buckle in any way at all. If it is buckled, let your local Decathlon workshop know when you take your bike for its free service (six months after purchase) so that they can adjust it for you.

There could be several reasons why your gears are not shifting smoothly or properly.  

 

1- Check the positioning of the cable end caps   Poorly positioned cable end caps can disrupt the derailleur cable and stop your gears shifting properly. If one of the end caps is out of place, use your hands to put it back in the correct place as shown below.  

 

2- The cable and housing may have jammed up   If your gears are struggling to shift onto the smallest chainrings, and the derailleur doesn't move even when you press the gear shifter, then the cable and the housing have probably jammed up. In this case, the cable and housing should be replaced. Take your mountain bike to a Decathlon workshop 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.  

 

3- Adjust the front derailleur    

There could be several reasons why your gears are not shifting smoothly or properly.  

 

1- Check that the derailleur hanger isn't bent.   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 as shown in the picture below. If the derailleur hanger is bent, visit a Decathlon workshop to have it replaced.   

 

2- Check the position of the cable end caps   Poorly positioned cable end caps can disrupt the derailleur cable and stop your back gears shifting properly. 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. In this case, the cable and housing should be replaced. Visit a Decathlon workshop to have this sorted out. 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.  

 

4- Adjust the rear derailleur  

If the brake lever is too slack, too limp or is touching the handlebar without much pressure being exerted on it, use the barrel on the brake lever to adjust the tension of the brake cable, as shown in the video below.   Unscrew the barrel and the locknut until the cable is sufficiently tight and the brake lever is firm but not too hard. Once you've got the tension right, tighten the locknut firmly against the brake lever to secure the setting. 

There are several reasons why your fork might be too 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. Squirt some oil on the pivots of the fork and move it around to work the oil into the blades.   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 and Decathlon cannot be held liable if you perform maintenance work incorrectly. If you are not sure how to do any of the maintenance procedures, please visit your nearest Decathlon workshop.

Your suspension fork will work best above 5°C. In temperatures below this, the suspension can harden up and stop working so well, but it won't get damaged.   It should start working normally again once you get back above 5°C. If you detect a fault, however, or you are not sure if your fork is in good condition, take it to your nearest Decathlon workshop and have it checked.