Although the brand has been pushing out e-MTB and gravel technologies over the past couple of years, Shimano has been super quiet on the mountain bike front with competitor SRAM stealing the show with its T-Type AXS drivetrains. However, that's set to change as Shimano has filed a fresh patent for what looks like its next generation of wireless mountain bike drivetrains. 

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A little while ago, we highlighted Shimano's patent for a Transmission style mech, but in this latest patent suggests the brand is going in a different direction. That said, it is electric, and its battery is held within the derailleur. 

2025 shimano derailleur patent 2.jpg, by Liam Mercer

Although Di2 has been around for a while now, it's been a long time since we've seen it on a mountain bike drivetrain, aside from the e-MTB-specific system. Rather, it's been common on the road scene, and increasingly so on gravel bikes with GRX Di2 gaining traction.

These drawings show a much more compact Shimano derailleur than we've seen on the road and gravel markets, which makes sense given the conditions mountain bikers put their mechs through. Packaging the motors into a smaller, less spread-out mechanism grants greater protection against rock strikes.

While it's fairly difficult to see from the images, it shows the battery is mounted inside the parallelogram. Additionally, the patent discusses two power sources, and that one or both may be moveable and mounted to the bike. It also suggests that a 'power generator' can charge the power source, whether through a dynamo system or otherwise is unclear.

2025 shimano shifter patent.jpg, by Liam Mercer

We've also stumbled upon a patent that shows what could be the shifter. It suggests that three switches on the shifter look to be actuated by the two triggers. What could be taken from the patent description is that both triggers have an intermediate and a final position. I guess the first position could equate to a single shift, whereas the final or third position could actuate multiple shifts, similar to what's seen on Shimano's Rapidfire Plus products.

But that's not all, as Shimano has filed a patent for the upcoming brake systems that we've caught glimpses of on pro bikes. We've found the patent for new finned brake pads that feature a new fin shape that's designed to increase the surface area of the pad's backing plate while guiding through the fins more efficiently. 

2024 shimano brake caliper patent.jpg, by Liam Mercer

This patent also covers a new brake caliper. It's a four-piston caliper that employs two different sizes of pistons. The patent also suggests that the caliper could be made from one piece or two, which hints that the same design could be run across Shimano's model range.

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