Can You Figure Out How This Bike-Powered Water Pump Works?

Nathan Hurst

Nathan Hurst is an editor at Make. He loves anything having to do with science or bicycling. He tweets as @nathanbhurst.

122 Articles

By Nathan Hurst

Nathan Hurst is an editor at Make. He loves anything having to do with science or bicycling. He tweets as @nathanbhurst.

122 Articles

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We passed this video around the newsroom and marveled at the clever device. (I must admit, it’s rather absorbing in a Zen kind of way.) The bike moves a rope equipped with white… chunks… through a PVC rig and pumps out an impressive stream of water. It’s rather efficient; it doesn’t even look like the guy on the bike is working that hard.

But watch first, and then see if our conclusion matches yours:

[youtube:https://youtu.be/Sxyac6EVsmM]

If you’ve seen rope pumps before, this was probably familiar to you. They’re actually not uncommon. According to ropepumps.org, the technology has been around for a thousand years, but had fallen out of use prior to a resurgence in Nicaragua.

The IRC International Water and Sanitation Center, in collaboration with the WHO, even refers to it as the “Nicaraguan rope pump.” That organization studied the performance, sustainability, cost-effectiveness, and more, of rope pumps in use in Nicaragua in 1995.

Illustration By Xofc/Wikimedia Commons

Rope pumps have also been studied for their effects on water quality, use in irrigation, and more. The conclusion, drawn by ropepumps.org, IRC, and others, is that while they are not exactly maintenance (or worry) free, the low cost and ease of use (or even ownership) make them highly useful, especially in areas without strong water infrastructure. As such, they’re often promoted and even installed by NGOs. A great deal of research goes into making them more efficient.

But back to the pump itself. Those aren’t cups or reservoirs that raise the water. They’re simply plugs (or pistons) foam cut to the same diameter as the pipe. Water flows in between the plugs and gets forced to the top, where it exits at the first opening. The deflated tire (bike or car or whatever) makes a good surface to seat the rope apparatus.

If you want to try this simple build — or one of the many variations on it — ropepumps.org has designs for three different models. If you build one, be sure to let us know! Send us a note on Facebook or in the comments.