Shimano Has Been Granted a Patent for Electronic Brakes (2024)

Based on the headline alone, I’m sure many of you are foaming at the mouth for details—or are already yelling into the screen, “BUT WHAT IF THE BATTERY DIES?!?!”

Realistically, it’s pretty likely that sometime in the next 10 to 20 years, electronic brake systems will be the norm on many kinds of bikes, whether we like it or not. As much as I might reflexively agree with the naysayers, "fly-by-wire systems" are already used in cars and planes. The concept is well-proven at this point. So, why use it on bikes, and what are the benefits?

Shimano is not yet openly discussing the specifics of a possible electronic braking system. When I reached out for comment, I got the standard Shimano “no comment” statement that they send out anytime I ask questions like this. I even reached out to multiple third-party brake manufacturers, such as Hayes and TRP, to get their thoughts, but both declined to offer any comment. However, there are enough details in the patent documents that we can at least make some educated guesses.

For example, certain kinds of race cars use brake mapping. This means that input at the brake pedal can create different outputs based on factors like speed, steering angle, etc. I could see an adaptation of this kind of tech on mountain bikes, where electronic suspension systems like Flight Attendant already make decisions without direct rider input. Alternatively, electronic braking could create very effective Anti-Lock Brake Systems (ABS) for heavier e-cargo bikes.

Shimano has three ideas for an electronic braking system: an electric-hydraulic hybrid system, a fully electric one, and an electric-mechanical hybrid system.

An electric-hydraulic hybrid system is the most interesting of the three. And it might be the one most likely to become a reality because it's very similar to systems currently used on cars. The system is identical to the hydraulic disc brakes currently used on bikes, but with the addition of some electrical wizardry inside the brake caliper. Instead of the fluid exerting pressure on the brake pads directly, a pressure sensor triggers a motor that moves the piston, which moves the fluid to engage the brakes. If that wasn’t complicated enough, the system seems to have two modes, the one I just described and a second mode where all the electronics are disengaged, and the brake works just like a normal hydraulic brake system via a sort of bypass valve.

The patent uses the word “selectively” to describe how the system uses each mode. This is incredibly vague and could mean that the brakes switch between modes automatically under certain conditions (like a fail-safe), or riders could manually select the braking mode they want to use.

The fully electric brake concept Shimano shows in the patent is the version that people on the internet will likely lose their minds over. There is no mechanical connection from the brake caliper to the lever. Based on the drawing in the patent documents, I can’t say if the system is wireless, although Shimano does not say that it is.

This system works like other brake-by-wire systems. When a rider pulls the brake lever, a signal is sent to the controller in the brake. The controller then makes whatever decision it needs and sends a braking signal to the motor that pushes the pads.

Finally, the patent also covers a mechanical-electric hybrid system. This system works similarly to current mechanical-hydraulic brake systems used on bikes, except instead of the cable activating a hydraulic piston, it activates an electronic controller that sends a signal to the motor that pushes the pads.

On the one hand, all of this feels entirely overcomplicated to accomplish something riders have been doing just fine for years. Then again, that’s how I thought about disc brakes ten years ago. And despite how much they sometimes annoy me, I’m not switching back to rim brakes anytime soon. Plus, using an electronic control system between two mechanical systems (the brake lever and the piston that pushes the pads) does open up some interesting possibilities.

I’ve already mentioned a system like ABS, but other compelling features could include automatic pad adjustment and location relative to the rotor. Plus, with only an electric wire connecting the levers to the brakes (if that's the system Shimano decides to go with), would open up some interesting frame design and integration options that are not currently possible with hydraulic lines.

While it might seem like early days for any kind of bike brake-by-wire system, Shimano filed this patent in 2019 (it was granted on April 30th, 2024), so it’s obvious that the company has been thinking about this technology for some time now. With the patent being granted, we might start seeing prototypes in the real world within a year or two.