The basic principle of how to set up an MTB rear derailleur perfectly has hardly changed for decades, regardless of the manufacturer and groupset. Anyone who knows the interplay of end stops, tension and the distance between the rear derailleur and cassette Once you have understood this, you can adjust any mountain bike drivetrain precisely with little effort. Current twelve-speed drivetrains (whether Shimano 1x12/2x12 or Sram Eagle) have a small gap between the individual sprockets and are therefore particularly sensitive. Often half a turn of the corresponding adjustment screws is enough to ensure flawless operation. The perfect setting must therefore be approached in small steps.
- the End stops/limiting screws of the rear derailleur
- the Distance between rear derailleur and cassette
- the Tensile stress
These three things can be adjusted quickly with just a few tools and a little experience and dexterity. Video instructions help immensely when working on the bike. That's why we have also produced a video guide on how to adjust Shimano 1x12 gears.
Adjusting the Shimano 1x12 gears: the video guide
The most important points of a Shimano XT 12-speed rear derailleur
The derailleur hanger (A) connects the rear derailleur and frame. Because it bends quickly, it can be replaced or aligned with the right tool. How to replace a how to repair a bent derailleur hanger on an MTB, read here.
The wrap-around screw (often also B-screw The so-called "upper pulley" ensures the correct distance between the rear derailleur and cassette. If you turn it in, the upper derailleur pulley moves away from the cassette.
The upper stop screw on Shimano is equipped with a H (high gear) and limits the outward swivelling range of the rear derailleur. It prevents the chain from falling between the frame and sprocket.
At Shimano, the lower stop screw is marked with the letter L (low gear) and limits the swivelling range of the rear derailleur inwards. It prevents the chain from falling between the spokes and sprocket.
Cable clamp (E): This screw clamps the cable to the rear derailleur. The cable tension is adjusted on the gear lever.
Shimano MTB rear derailleurs also feature derailleur damping, which calms the chain when riding off-road. Shimano recommends deactivating the damping with the plastic lever to adjust the shifting.
>> Not yet riding a Shimano 1x12-speed drivetrain, but still pedalling with a 2x drivetrain? Then this way, There we show in detail how to set up a 2x12 circuit perfectly.
