MTB drivetrain components: How well do Shimano, Sram & Co. fit together?

There are many reasons to combine shifting components from different manufacturers (such as Shimano, Sram or other chain or chainring manufacturers) on a mountain bike. Especially in times of supply bottlenecks, some people are tempted to fall back on alternatives from the competition if the desired original part is not available. Or they may be tempted by a bargain in the form of a new sprocket set at a special price to replace the worn one - of course it is not from the same company as the one on their own bike. Others are simply tempted by the technical gimmick.

However, this is often a game of chance, as tests with a wide variety of drivetrain parts and MTB drivetrain components from Shimano, Sram and others in the BIKE test workshop have shown. For example, special climbing aids and different distances between the individual sprockets make Twelve-speed cassettes from Sram and Shimano incompatible. Even with certain combinations of older and newer models from the same manufacturer, you cannot be sure that the parts will harmonise with each other and that the MTB drivetrain will work perfectly. As with many other mountain bike parts, the number of different standards for drivetrain and drivetrain components is growing.

Generation conflict: Combining 10-speed/11-speed parts with 1x12 drivetrains?

MTB drivetrain components from older ten-speed (3x10 or 2x10) or eleven-speed drivetrains (e.g. Sram 1x11 components) cannot be combined with current twelve-speed MTB drivetrains. This does not work with either Sram or Shimano, nor does it work across manufacturers.

Mix Sram and Shimano rear derailleur/shift lever?

The rear derailleur and shifters should be either from Shimano or Sram in order to harmonise perfectly in terms of function. TRP (twelve-speed) and Box Components (eleven-speed) offer replacement derailleurs for Shimano. There are no third-party replacement derailleurs for Sram.

Freewheel: 3 standards on the MTB

The freewheel is the interface between the wheel and the cassette. There are now three freewheel standards, for each of which there are special cassettes. In the past, both Shimano and Sram used the HG freehub. Today, both have their own standards for freehub bodies: Shimano uses the Micro-Spline freehub for twelve-speed cassettes. Sram relies on the Sram XD standard. It is suitable for eleven- and twelve-speed cassettes (Eagle) from Sram.

MTB cassettes: 12-speed models from Shimano and Sram

It is better not to combine Shimano cassettes with Sram rear derailleurs. You should also refrain from combining Sram Eagle cassettes with a Shimano 12-speed rear derailleur. If you want to swap a Sram cassette with a 50-tooth sprocket for a sprocket set with an extra-large 52-tooth "rescue sprocket" for the steepest climbs, you will need a Sram Eagle rear derailleur with a cage labelled "520%" to ensure proper functioning. Third-party suppliers such as E13 offer universal retrofit cassettes for 1x12 drivetrains. They usually compromise on the sprocket spacing in order to remain compatible with both Shimano rear derailleurs and Sram drivetrains.

Chainrings

With the Introduction of single drivetrains from Sram the tooth profile of the chainrings has also changed significantly. Sram relies on a profile with alternating thick and thin teeth in a shark tooth shape (Sram X-Sync). Shimano has also introduced a narrow-width profile for its twelve-speed cranks with its chainrings. An alternative are cranks with chainrings from third-party suppliers. They can be combined with any drivetrain - whether Sram or Shimano. The chainrings and cranks from E13 are approved for all 1x12 drivetrains. This trick allows you to mix current and older cranks and drivetrains from Sram or Shimano.

Note the chain line when replacing!

In addition to the mounting standard on the crank and the matching tooth profile, the chainline matching the mountain bike must be taken into account when replacing the chainring.
Bikes with Boost rear triangle require a chainring with a 3 mm offset. Bikes with a narrower installation dimension for the rear wheel require an offset of at least six millimetres to maintain the chainline.