Shimano 12-speed (12s) sprocket types and compatibility summary

Posted at: Oct. 1, 2021

We have compiled a list of the different types of 12-speed (12s) sprockets, which are Shimano's top upper grade gears for road bikes and MTBs. Differences between models and points to consider when choosing.

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Types of Shimano sprockets for 12-speed (12s)

CS-R9200-12

The sprockets of the current model of Shimano’s top-of-the-line DURA-ACE components for road use, which are compatible with both 12-specific wheels and conventional 11-speed wheels.

The sprockets are compatible with both 12-speed wheels and conventional 11-speed wheels. In order to increase the number of stages, only wide-ratio sprockets are available.

Model Number High Low Weight Gear Combination
CS-R9200-12 11T 30T 223g 11-12-13-14-15-16-17-19-21-24-27-30
CS-R9200-12 11T 34T 253g 11-12-13-14-15-17-19-21-24-27-30-34

CS-R8100-12

This is the current model sprocket of Shimano’s ULTEGRA top-level road component, and like the CS-R9200-12, it is compatible with both 12-specific wheels and conventional 11-speed wheels.

As with the CS-R9200-12, only wide-ratio sprockets are available in the lineup.

Model Number High Low Weight Gear Combination
CS-R8100-12 11T 30T 291g 11-12-13-14-15-16-17-19-21-24-27-30
CS-R8100-12 11T 34T 345g 11-12-13-14-15-17-19-21-24-27-30-34

CS-M9100-12

This is the current model sprocket of Shimano’s top-of-the-line XTR component for MTB. It is a special sprocket that consists of three metals: aluminum for the three pieces on the low side, titanium for the five pieces in the middle, and steel for the four pieces on the top side.

The top sprocket is 10T, which is smaller than the previous 11T, and the low sprocket is an amazing ultra-wide ratio sprocket with a maximum of 51T. Cross-ratio sprockets are not available in the lineup.

Model Number High Low Weight Gear Combination
CS-M9100-12 10T 45T 357g 10-12-14-16-18-21-24-28-32-36-40-45
CS-M9100-12 10T 51T 367g 10-12-14-16-18-21-24-28-33-39-45-51

CS-M8100-12

This is a sprocket of the current model of Shimano’s DEORE XT, a top-level component for MTB. The two low side sprockets are steel, and the other 10 are aluminum.

The top sprocket is 10T, which is smaller than the previous 11T, and the low sprocket is 51T, which is the same as the top model CS-M9100-12.

Model Number High Low Weight Gear Combination
CS-M8100-12 10T 45T 461g 10-12-14-16-18-21-24-28-32-36-40-45
CS-M8100-12 10T 51T 470g 10-12-14-16-18-21-24-28-33-39-45-51

CS-M7100-12

This is a sprocket of the current model of Shimano’s SLX, a top-level component for MTB. One sprocket on the low side is made of steel, and the other 11 are made of aluminum.

The gear configuration is the same as the higher-end models CS-M9100-12 and CS-M8100-12, but the weight is super heavy, exceeding 500g.

Model Number High Low Weight Gear Combination
CS-M7100-12 10T 45T 513g 10-12-14-16-18-21-24-28-32-36-40-45
CS-M7100-12 10T 51T 534g 10-12-14-16-18-21-24-28-33-39-45-51

Compatibility of Shimano 12-speed sprockets and wheels

The compatibility of Shimano 12-speed sprockets and wheels can be summarized as follows.

Wheel/Sprocket 12-speed sprocket (Road) 12-speed sprocket (MTB)
12-Speed Wheel (Road) -
12-Speed Wheel (MTB) -
11-Speed Wheel (Road) -
11-Speed Wheel (MTB) - -

12-speed road sprockets and MTB sprockets are not interchangeable.

Until now, road sprockets and MTB sprockets were interchangeable as long as the capacity of the drivetrain was the same, but with the new 12-speed, the free bodies for road and MTB sprockets are completely different, making them incompatible.

The 12-speed for MTB is a free standard called “MICRO SPLINE”, but the 12-speed for road is a different proprietary standard.

12-speed sprockets for road use are compatible with 11-speed wheels

The 12-speed sprocket for road use is shaped to be compatible with conventional 11-speed wheels, while increasing the number of slits in the freebody. In other words, it is compatible with both 12-speed wheels and 11-speed wheels.

On the other hand, the freebodies of 12-speed wheels are shaped differently from those of 11-speed wheels, so sprockets of 11-speed or lower cannot be used with 12-speed wheels.

12-speed sprockets for MTB are not compatible with 11-speed wheels

The 12-speed sprocket for MTB is not compatible with 11-speed wheels because it is a proprietary sprocket for MICRO SPLINE.

Since 11-speed wheels for MTB are the same standard as 11-speed wheels for road use, it is possible to install 12-speed sprockets for road use, but since they are not officially compatible with Shimano, it is not clear if they will work correctly with MTB drivetrains.

Where are the differences between the products?

Shimano’s 12-speed sprockets were previously only available in the MTB component lineup, but with the announcement of 12-speeds for road bikes in September 2021, the lineup has become wider.

However, since there is no interchangeability between 12-speeds for road and MTB, the choice itself is not very wide.

The major difference is the material and weight

The main difference between Shimano’s 12-speed sprockets is the material used and the weight associated with it.

In particular, the top-of-the-line CS-R9200-12 and CS-M9100-12 are extremely light, even with the same gear configuration, and are 1.5 times lighter than the lower-end CS-R8100-12 and CS-M7100-12. The weight is about 1.5 times less than the CS-R8100-12 and CS-M7100-12.

As for the materials, there are the following differences

  1. whether titanium is available
  2. what is the ratio of steel to aluminum

All gear configurations are the same

There is no difference in Shimano’s 12-speed sprockets for road and MTB bikes, but the gear configuration is the same for all models in the same category.

There are two options for road use, 11-30T and 11-34T, and two options for MTB use, 10-45T and 10-51T, and among the two, you can choose between cross or wide.

How to tell a 12-speed sprocket apart

As for 12-speed sprockets, it is very easy to tell them apart by appearance. The first thing to look for is the number of black gears on the low side.

First of all, MTB 12-speed sprockets can be identified by the number of black gears on the low side.

  1. 3 black gears -> CS-M9100-12
  2. 2 black gears -> CS-M8100-12 1 black gear -> CS-M7100-12

For road use, the CS-R9200-12 has a different coloring for the five low side gears, and the CS-R8100-12 has all silver gears.

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