These NFC Pressure Valve Sensors Provide Battery-Free Bike Tire Monitoring

If you own a bicycle, you have probably noticed that you have to pump up the tires far more frequently than you would have to for car tires. That is partially because of the way the tires/tubes and valves are constructed, and partially because of the pressures they’re under. Automotive tires rarely have recommended pressures exceeding 35 PSI, while road bike tires can require as much as 130 PSI. Because those pressures are so high, it can be difficult to tell if your tires are adequately inflated until you actually start riding. That’s why CaptMcAllister developed these battery-free NFC pressure sensors for bike valves.

There are already valve caps on the market that screw right onto your valve stems and provide a physical indicator (usually color coded) of your tire’s pressure, but they’re very imprecise and aren’t adjustable at all. You have to just purchase caps rated for the tire pressure you think you want. This small device solves both problems by taking real time electronic measurements of your tire pressure that you can check whenever you want. About to go on a nice long bike ride? Just pull out your smartphone and scan the valve to check that your tire pressure is what it should be. Yes, this does make your valve stem much bulkier, but not enough to affect your cycling performance by any appreciable amount.

This is actually an evolution of an earlier project, but that required that the pressure sensor be built into the tire during manufacturing. This new design can be attached to any valve stem, though the prototypes are made for Presta valves. Those prototypes were fitted to standard valve extensions that were milled to create a small access hole for the pressure sensor. The PCB containing the sensor is very small — roughly the size of a nickel. The PCB and valve were held in a small 3D-printed mold that was then used with a hand-operated injection molding machine to encapsulate the components in a sturdy plastic enclosure. Obviously not many makers have access to CNC mills or injection molding machines, so it is unlikely that you’ll be able to make these pressure sensor valves yourself. Fortunately, CaptMcAllister’s team at Rover Development LLC is currently evaluating interest to see if a crowdfunding campaign would be appropriate.