As much as e-MTBs and non-motorised bikes now differ in terms of geometry, weight and design: There is no difference in the gear shifting technology. Of course, the individual models from Sram, Shimano - and others, which will be neglected here due to their relatively rare use - are somewhat different. We will discuss both brands separately below. However, the tips shown here for adjusting the gears can be used for MTBs with and without a motor.
Preparation for setting the gearstick
To be able to work well on the gears, the rear wheel must be able to turn freely. The best solution: the Mounting stand. With carbon frames in particular, however, it is better to clamp the bike to the seatpost, as the frame itself is very sensitive. If this is also made of carbon fibre, you may have a suitable "mounting" seatpost lying around at home. If not, or if you don't have a mounting stand, you can also turn the bike upside down. However, it is better to remove sensitive fittings and displays or cushion them with a soft pad (cloth, foam). The chain and sprockets should also be well cleaned!
Step 1: How should the rear derailleur be positioned?
Loose or damaged parts are the most common cause of shifting problems. Therefore, before adjusting the derailleur, first check the fixing screws on the derailleur hanger and the large screw on the rear derailleur as well as the derailleur hanger itself. To do this, engage a middle gear. The two derailleur pulleys must be in an exactly straight line with the sprocket (red line in the photo below) and parallel to the direction of travel. Otherwise the Bent derailleur hanger and must be repaired or replaced.
Step 2: Check the outer casing and cables
The second typical source of faults in a gear shift: wear on cables and outer casings. If they are corroded or individual strands have come loose, the friction in the sheaths is too high and the gearstick cannot function properly. The best way to check this is to shift from the largest to the smallest sprocket without cranking. This elongates the cable so that the end caps on the outer casing can be pulled off. In the event of corrosion or damage: Replace everything and Fit new cables and outer casings to the bike! Below you will find a good tip for lubricating the trains.
Step 3: Setting the MTB derailleur stops
If the chain jumps off the cassette, the end stops are not correct. To check the upper stop (B: upper screw), shift to the largest sprocket. Then turn the crank carefully and press the gear lever further. If the chain now moves over the sprocket into the spokes, the right-hand stop screw (B) must be screwed in slightly. The lower stop is more difficult to check, as the rear derailleur is often held in position by the tension. Therefore: First check whether the derailleur pulley is exactly aligned with the smallest sprocket. Then use the lower screw (A) to align it so that it jumps easily and precisely onto the next sprocket when shifting.
Step 4: Setting the tension
The tension of the derailleur is adjusted on the shifter so that all gears can be used. If the chain does not shift into the easiest gear, the tension is too low and the adjustment screw must be unscrewed (anti-clockwise). This screw is located in front of Sram, a little before the gear lever.
If the derailleur does not shift into the heaviest gear, the tension is too high. If the chain shifts equally quickly to lighter and heavier gears at the end and all gears can be used, the tension is set correctly. If the adjustment range is not sufficient, the cable on the rear derailleur must be tightened or lengthened.
Step 5: Setting the wrap
Use the wrap screw (A) to adjust the distance between the upper derailleur pulley and the cassette. If the distance is too large, the shifting will be very sluggish. If it is too small, the shifting starts to chatter in easy gears. With Shimano, there should be about two chain links between the derailleur pulley and cassette in the lightest gear. Shimano's twelve-speed derailleurs also have a guide line inside the cage, which should be aligned with the cassette teeth in the easiest gear. With Sram drivetrains, you should use the Chain-Gap-Tool for the adjustment. use.
Adjusting the Sram gears
In the 90s, it was "awesome" to have a 27-speed drivetrain on an MTB - top score: three chainrings at the front, nine at the rear. Since then - triggered by the development of the Sram company - there has been a major rethink and we now shift to 9 to 12 sprockets at the rear. However, current bikes only have one chainring at the front, while slightly older bikes (or racing bikes) still have two. For this reason, we have linked various how-tos and guidelines below, so that there is something for (almost) every shifting variant.
Setting the Sram 1x12 drivetrain
The latest variant from Sram is the 1x12-speed MTB drivetrain. With a range of 10 to 50 teeth and possibly with the oversized Eagle sprocket, the distances between the gears have become much smaller than before and the shifting is correspondingly more sensitive. We show you how to adjust your Sram gears precisely in the Instructions: Adjusting the Sram 1x12 drivetrain.
Whether e-mountain bike or non-motorised MTB: With Sram drivetrains, you have to adjust the wrap on fullys in the sag (negative suspension travel). You need a special gauge for this - the Chain-Gap-Tool - and ideally an assistant who either weighs about the same as the driver or who turns the adjusting screw for you.
Setting the Sram 1x11 drivetrain
Sram's 11-speed drivetrains also require a sure instinct. Because even small inaccuracies in the setting can mean the difference between a smooth-running drivetrain and chain rattling. We show you how to adjust your 1x11 drivetrain from Sram using the three adjusting screws. The dial on the shift lever is used again to achieve the optimum tension. How to set up a 1x11 drivetrain from Sram correctly.
Everything set up correctly, but the gears still don't work properly? Then it's worth taking a second look at the wearing parts. A worn chain that is too long or a worn sprocket often prevent the drivetrain from being adjusted correctly. Then the only solution is to replace them.
Adjusting the Shimano gears
From 2020, a Shimano 1x12 drivetrain was also more frequently installed on mountain bikes - Mass-compatible in the Deore version. It took the Japanese a moment before they followed the trend towards single shifting. BIKE shows you how to perfectly adjust the rear derailleur of a Shimano XT with just a few simple steps. The basic principle of how to perfectly adjust an MTB derailleur has hardly changed for decades, regardless of the manufacturer or groupset.
Setting the Shimano 1x12 gears
Due to the small distance between the individual sprockets, half a turn is often enough to make the difference. The perfect gear setting must therefore be approached in small steps with the Instructions: Adjusting the Shimano 1x12 drivetrain. You will also find a detailed video there.
Setting the Shimano 2x12 gears
Unlike Sram, Shimano still offers an option with two chainrings. The advantages in favour of a 2x12 drivetrain are obvious: there is no current MTB drivetrain with a wider range (total gear ratio) and such a fine gradation of gears. The difference between the single and double drivetrains is the additional front derailleur. This is not quite as sensitive as the rear derailleur, but must be adjusted just as precisely so that the chain neither bites into the bottom bracket ("chainsuck") nor jumps over the large chainring. But you can do this quickly with our instructions: Shimano 2x12 gears: Adjusting the derailleur.
Finally: 3-speed gearstick, retensioning and lubrication
In times of delivery difficulties, with beloved old treasures and the faithful city MTB that has been doing its job since 1997: How you can also make your old Adjusting the Shimano rear derailleur and front derailleuryou can find out in this article and video.
Shimano recommends - if available on the rear derailleur - that you use the Clutch system (Shadow Plus) to deactivate.
If you have installed a new shift cable, you should block the rear derailleur by hand and shift up one or two gears several times. This will lengthen the cable slightly and you saves retensioning of the new train after a few kilometres.
If you are installing new cables, treat the steel cables to a little extra care before installation. Special lubricating grease. To do this, put some lubricant on your fingers and pull the cable through the grease. It can then be pushed through the outer casing. This makes it easier and the shift cable is protected against corrosion and dirt and glides much more smoothly. But be careful: Only use grease that is explicitly intended for this purpose. Grease that is too viscous can literally stick the cable together.
>> For all those who have installed or upgraded a new Sram AXS, we show in Sram AXS: This is how easy it is to set up the electronic gearstick Everything from the first pairing of the components to the firmware update.
>> It's not just the gears that require regular maintenance. The other areas of an E-MTB also require care and attention if they are to function optimally. In Do-it-yourself e-bike maintenance: Wellness programme for e-MTBs - find out all the tips for your home service station.
>> However, the centrepiece of every e-bike requires special attention during maintenance: the battery. Read our text on this subject 9 answers: How to extend the e-bike battery life.
Adrian Kaether
Editor
