Are Self Powered Dropper post the Future for MTB

Last week on Pinkbike, there was a press release for a dropper post from the new brand Zerro that goes up and down by itself. The normal way that a dropper post works is that it can go up under its own power, but in order for it to go down, the rider needs to use their weight to push and compress it. It seems like something small, but if possible, it would change the way people ride mountain bikes.

At first, this problem sounds simple, but upon deeper thought, it actually seems more challenging. The normal way that a dropper post works is that when the post moves downwards under the weight of the rider, it compresses a spring (or pressurized air chamber). Then, when the lever is pressed on the handlebar, the spring releases stored energy for the post to go back up.

The problem with a post that goes up and down under its own power is that the energy needs to come from somewhere. Every time the post goes up and down, it uses some energy, and it has to come from some external source.

The only production example of a self-powered dropper post in the wild is fully integrated into the BMC Fourstroke XC race bike. This seat post works via an extra air chamber that is used to push the post down; this extra air chamber needs to be pumped up each ride. This secondary air chamber approach seems like one of the most intuitive ways to make this work. The only other idea that I have to make something like this work is something battery-operated, although it seems like it would take a lot of power to push the post down every time, so the battery life may be limited.

There were only limited details on how this new Zerro post works, but it looks like it uses two cables to actuate the post instead of one. Upon further investigation, on Zerro’s website, they say the post doesn't use batteries or compressed gas to make the post move. The combination of these two things suggests that the post is being powered by the movement of the lever, but to me, it seems like the force that would be required to push the lever would be quite high to be able to move the post all the way up or down.

Regardless of how this technology works, it would be exciting to see how different companies will tackle this problem. If this technology ever does make it into the real world, I do think that it would be seen as a step forward in mountain bike tech, and it would become the new standard.