Summary of electric components for MTB

Di2 (Shimano)

Shimano is the world’s number one manufacturer of bicycle parts. Shimano’s electric shifting system is called “Di2” for both road and MTB.

Di2 | Shimano

Di2 Components for MTB

Of Shimano’s current components for MTB, only the M9050 series, the previous generation of XTRs in the current model range, supports Di2, and only with 11 speeds. The current XTR M9100 series, DEORE XT and SLX are not Di2 compatible.

The older DEORE XT has a Di2 model (M8050 series), but it too is an 11-speed model. The current DEORE XT is a 12-speed model, but the M8100 series, the 12-speed series of DEORE XT, does not have a Di2 lineup.

The latest DEORE XT Di2 is marketed as an eMTB component and is only compatible with models equipped with Shimano’s EP6 and EP801 e-bike units, so it cannot be used on standard MTBs.

Advantages of Di2

The advantages of Shimano’s Di2 are its high availability and cost performance.

Shimano is a Japanese manufacturer, so availability in Japan is very high, and if a specialized sports bicycle store has it in stock, it is readily available.

In addition, some parts of Di2, such as the junction unit and battery unit, are shared between road and MTB, so Di2, which has more users, is more widely distributed in the used market.

Disadvantages of Di2

The disadvantages of Di2 for MTB are the lack of options, the lack of support for rear 12-speed, and the fact that it is wired.

Shimano’s Di2 for MTB is only available in the 11-speed era, so it does not support 12-speed electric shifting, and there are no Di2 options for the DEORE XT and SLX.

Also, both the M9050 and M8050 have the older wire-type electric shifters instead of the “semi-wireless Di2” introduced in the latest road models, which seems a bit dated at this point.

We look forward to future updates in Shimano’s road-oriented components, as not only the top-of-the-line DURA-ACE, but also ULTEGRA and 105 are now available with 12-speed Di2.

AXS (SRAM)

SRAM is ahead of the curve in the MTB genre with its 12-speed and electric shifting, and SRAM’s electric components are called the AXS series, which not only provide shifting, but also dropper seat post operation.

Advantages of AXS

The advantages of SRAM AXS are ease of upgrade, wide compatibility, and complete wireless.

First of all, SRAM’s AXS series is compatible with both RED for road and Eagle for MTB. In addition, sprockets, chainrings, and chains are also compatible with mechanical components, so at a minimum, only the derailleur and shifter need to be replaced to enable electric shifting.

Another strength of SRAM is its “fully wireless components.

While its rival Shimano’s Di2 supports “semi-wireless (only the shift switch is wireless)” in its latest models, SRAM’s current AXS is completely wireless. The derailleur itself incorporates a battery, so there is no need for even a battery unit, and with the Eagle Transmission, an evolution of the Eagle AXS to be announced in March 2023, even the number of chain frames and shifting can be adjusted electrically.

Comparing Electric Components for MTB

Finally, let’s compare Shimano Di2 and SRAM AXS.

Shimano Di2 for road use has a wider range of options due to the Di2 version of the 105 in 2022, but for MTB use, it is currently narrower. However, Shimano’s products are cosmetic in price, and their high availability is a strength.

On the other hand, SRAM is a step ahead in the MTB genre in terms of “advanced” features such as wireless technology and rear 12-speed. Although the price is higher, if you want to use the “latest technology in electric components,” you should probably choose SRAM.