B'TWIN MOUNTAIN BIKE ROCKRIDER 540 - GREY

For optimal brake performance, you need to bed in your brakes in advance. The brake pads and discs on a new bike are new themselves and don't work to their full potential.

 

Brakes will be ready after braking 10 times per brake, meaning to decelerate quickly from about 25 km/h to 5 km/h without fully blocking the wheel, using just a single brake at a time.

Your ROCKRIDER 520 may be equipped with two different forks.

 

They can be adjusted as follows:

1/ SUNTOUR XCT fork

 

If your fork has 2 adjustment buttons, they are totally independent of each other. You can use the first, then if the level of stiffness is not enough once the 1st is fully screwed in, use the 2nd. Turn the wheel clockwise to increase hardness, and anti-clockwise to decrease hardness.

 

2/ BTWIN U-Fit Fork The U-Fit fork has been to designed to make adjustment as easy as possible. A true innovation, just 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 ideal tyre pressure is determined by the weight of the user.

 

The tyre pressure based on user weight is the perfect compromise between performance and resistance to pinching (pinching of the inner tube can cause punctures).

 

If you're looking for more grip, you can reduce the pressure by 10% but without dropping below 2 bar (the minimum recommended pressure). On abrasive terrain, however, this will increase the risk of punctures.

If your fork is too hard, that can be due to several factors.  

1- Adjustment   Visit the section on "adjusting your fork" to easily adjust the hardness based on your preferences.  

2- Basic maintenance   Forks can be maintained regularly with 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- Full maintenance   If basic adjustment and maintenance aren't enough, you need to fully service your fork as shown in the video below.  

If you undertake the adjustment and maintenance of your fork, Decathlon can not be held responsible in case of poor practice. If you aren't certain of the proper action to take, visit your nearest Decathlon workshop.

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 wheels should not buckle in any way at all. If they do, then make the most of the free check-up available to you within six months of purchase and call in at one of our Decathlon workshops to have it repaired free of charge.

If your lever becomes soft and/or touches the handlebars before braking, you should purge your brake system as shown in the video below. You can also visit one of our Decathlon workshops to get our technicians to do this for you.

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

1- Check that the derailleur dropout is not twisted.   A twisted dropout causes the derailleur to become misaligned, preventing it from doing its job correctly.  From behind your bike, look at the alignment of the derailleur as shown in the image below. If the dropout is twisted, visit a Decathlon workshop to replace the derailleur dropout.   

2- Check the placement of the housing caps   Poorly placed housing caps can impede the movement of the derailleur cable and cause rear shifting to lose its adjustment. For the rear derailleur, there are 4 housing cap placements to check. If a housing cap is out of place, return it to its place by hand.  

3- The cable and/or housing may have seized up   If, in particular, 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, then the cable and/or housing have almost certainly seized up. In this case, the cable and housing should be replaced. Visit one of our Decathlon workshops. 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.   

4- Adjust the rear derailleur  

Your suspension fork operates best when the temperature is 5°C and over. Below that temperature, the cold can cause the suspension to harden until it locks up, but will not damage it.   It should begin functioning normally as soon as the temperature returns to at least 5°C. If you continue to 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 straightaway.

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

1- Check the position of the housing caps   Poorly placed housing caps can impede the movement of the derailleur cable and cause the rear gears to lose their adjustment. If a housing cap is out of place, return it to its place by hand as shown in the image below.  

2- The cable and housings may have jammed up   If it is particularly difficult to shift down to the smallest gears (chainrings), if the derailleur doesn't move even when the gear shifter is operated, then the cable and the housings have jammed up. In this case, the cable and housing should be replaced. Visit a Decathlon workshop or replace them yourself with the help of this video. 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.  

3- Adjust the front derailleur