Fox Patent Shows Heart Rate or GPS Controlled Dropper Post

Imagine you're in the middle of an XC race, maintaining a grueling pace at the head of the pack, when you arrive at a technical downhill section. Typically, you'd push the remote lever for your dropper post, weight the saddle to lower it, and then stand up again to make it through that tricky bit of trail. Not this time. Instead, once you reach a predetermined GPS coordinate, the post lowers by itself, and you're able to continue on without even thinking about pushing any levers. It's not as far-fetched as it seem, epecially since that's just one of the many scenarios laid out in a recent patent granted to Fox earlier this month.

The patent has the innocuous title of 'Seat post', but a closer examination reveals some fascinating possibilities. The most compelling details describe a post with an electronic motor at the base that allows it to raise and lower on command. This isn't the first time we've seen a patent for a seat post that can lower on its own – Shimano has supposedly had a motorized one in the works since all the way back in 2009, and Trek was granted a patent for an auto-dropping dropper back in 2016. And don't forget BMC's Autodrop post that emerged in 2019, one of the first real-world examples that the concept could work.


A Heart Rate Controlled Dropper

Fox's patent takes things a step further, presenting a wide range of options, including one that would have the post raise and lower based on a rider's heart rate.

According to the patent, “In one embodiment, the seat post is actuated by a controller designed for receiving and analyzing input associated with a cyclist's heart rate as well as the cyclist's GPS coordinates. For example, if the controller receives input that describes the cyclist's heart rate as being lower than a given preprogrammed threshold while riding, then the controller may signal to the seat post to move up or down, causing the cyclist's work rate and heart rate to increase or decrease.

In another example, if the controller receives input that describes the cyclist's GPS coordinates as being such that the cyclist is just about to arrive at terrain having a steep descent, the controller may cause the seat post to lower in preparation for the descent.”

Those may not seem like the most practical applications, although I could envision them being tested out in the cross-country or even enduro racing worlds. If a rider was able to pre-ride a track and program in the sections where they wanted their dropper to raise or lower, potentially while their suspension settings changed at the same time, that would allow them to focus even more on riding and less on fiddling with lever. The patent does mention the ability to combined the dropper post height with suspension adjustment, and shifting adjustment is mentioned as well, raising the idea of a nearly fully automated bike, one that requires minimal input from the rider other than pedaling effort.

In another section, the patent has an extensive list of the various components that could possibly communicate with the post, including a wireless device, power meter, heart rate monitor, voice activation device, GPS device, graphical user interface, button, dial, smartphone, and lever. The idea of someone shouting furiously at their dropper post deep in the woods cracks me up, but it's clear Fox wanted to cast a large net with this patent in order to cover as many configurations as possible.




How does it work?

The patent lays out a few different possibilities as to how the post will function, but the overall concept is that a small motor at the base of the post receives instructions, either wirelessly or via a cable, and then raises or lowers the post accordingly. The motor is connected to a cam which then opens or closes check valves that allow the post to raise or lower. A PID controller is used to monitor the motor's speed. When the post nears the desired height, the motor slows down, allowing the post to arrive smoothly, rather than with a jarring finish.


When will this futuristic dropper post be available?

I've contacted Fox to see if they'll divulge any more information, but if I had to guess the answer will be, “Not any time soon.” Remember, we still haven't seen any finished products hit the market from Trek or Shimano, and they patented droppers intended to accomplish a similar goal years ago. Fox's GPS, heart rate, and suspension integration features are all clever, although I sort of hope they're not the future. Maybe it's the Luddite in me, but I'm confident I can figure out when to lower my seat post and adjust my suspension on my own, thank you very much.

I'm much more intrigued by the concept of a post that lowers by itself when I push a button than anything else. Make it strong, as low-maintenance as possible, and then sign me up.