Bicycles

Battery-free PSIcle sensor transmits tire pressure data to smartphones

Battery-free PSIcle sensor tra...
The PSIcle sensor (hidden here by the smartphone) is currently on Kickstarter
The PSIcle sensor (hidden here by the smartphone) is currently on Kickstarter
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Each PSIcle sensor weighs a claimed 5 grams
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Each PSIcle sensor weighs a claimed 5 grams
There are two versions of the PSIcle sensor, one for road bikes and one for mountain bikes
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There are two versions of the PSIcle sensor, one for road bikes and one for mountain bikes
The PSIcle sensor (hidden here by the smartphone) is currently on Kickstarter
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The PSIcle sensor (hidden here by the smartphone) is currently on Kickstarter
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Checking your bike's tire pressure can be a fiddly process, which is why there are now valve stem attachments that let you check it with your smartphone. The just-announced PSIcle sensor makes things even easier, as it doesn't require a battery.

Some readers may recall the TyreWiz and the Airspy, both of which are screwed onto the valve stem of a third-party inner tube (or tubeless rim) then left in place.

They proceed to continuously monitor the air pressure, utilizing Bluetooth or ANT + to wirelessly transmit that data to an app on the cyclist's phone. Because they're battery-powered, however, they regularly need to be recharged, plus they're heavier and bulkier than they would be otherwise.

Austrian manufacturer Tubolito recently took a different approach, with an inner tube that incorporates a pressure-sensing NFC (near field communication) chip. That battery-free chip is temporarily powered up by the radio waves emitted by a nearby NFC-capable smartphone.

As a result, users can check their tire pressure simply by stopping and holding their phone close to the chip. That said, because the chip is integrated into the tube, it can't be used with tubes made by other manufacturers, or with tubeless tires … and that's where the PSIcle sensor comes in.

There are two versions of the PSIcle sensor, one for road bikes and one for mountain bikes
There are two versions of the PSIcle sensor, one for road bikes and one for mountain bikes

Created by Minneapolis-based engineers Chris Larsen and Jeremy Hipp, the waterproof device is simply screwed onto the end of a third-party tube or tubeless rim's Presta valve stem – the only stipulation is that the stem does need to have a removable core. Once in place, it works much like the Tubolito tube … it's powered as needed by a smartphone held about 1 inch (25 mm) away, transmitting air pressure readings to an iOS/Android app on that phone.

The PSIcle sensor itself is made of anodized aluminum coated with EPDM rubber, it measures 40 mm long by 6 mm thick by 22 mm in diameter, and reportedly tips the scales at just 5 grams. It's being offered in two versions: the LP, which reads mountain bikes' tire pressure from 0 to 40 psi (2.75 bar) – plus or minus 0.06 psi – and the HP, which reads road bikes' tire pressure from 0 to 400 psi (27.5 bar) – plus or minus 0.7 psi.

Needless to say, both models are intended for use while the bicycle is not in motion. It should be noted that the TyreWiz and Airspy do transmit live readings as the bike is moving, sounding an alert if the pressure gets too low.

Should you be interested, the PSIcle sensor is presently the subject of a Kickstarter campaign. Assuming it reaches production, a pledge of US$52 will get you a set of two – the planned retail price is $56 a pair.

Sources: Kickstarter, Rover Development

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Expanded Viewpoint
Someone, other than me, of course, needs to buy some of these to put into the Museum of Stupid Ideas for permanent display! Unless you have a pump and patch kit with you, what is the point of knowing the exact amount of pressure in your bike's tires as you ride it? Before you hop onto the saddle, you give the tires a squeeze with your thumb and forefinger to see how hard they are! Or, lift the bike wheels about 4" off the ground and drop it to see how high it bounces! If the rolling resistance is too high for your liking, put some more air in the tires before you roll out onto the street. Is making a bicycle into a rocket ship really a good idea?

Randy