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TECH NEWS

Pumptire: the tyre that pumps itself up + video

Clever commuter technology or pie in the sky? Well they've got a working prototype...

A tyre that pumps itself up? Surely this is science fiction? Nope. Well, actually it's a tire that pumps itself up, because the Pumptire hails from the US of A, but it does exactly what it says on the tin. But how?

Here's how. the tyre incorporates a thin tube that runs around the circumference of the tyre. When the tyre is in contact with the ground the tube is squeezed, and this forces air into the tyre. So the more you ride, the more pressure you get. Like this:

That's the basics, and Pumptire aren't giving much away other than that. Presumably there's some kind of valve to let the air in to the main tyre chamber (the tyre will need to be tubeless, or at least incorporate a built in tube) and presumably that valve can be set to stay closed at a certain pressure so that you don't blow your tyres off the rim on a long jaunt. Pumptire say on their website, "imagine yourself being able to change your tire pressure on-the-fly with a simple adjustment from the handlebars", which suggests they're also working on a system where you can adjust the trigger pressure of the valve. Interesting.

Anyway, they've got a working protoype as you can see in the vid. At the moment the tube stands proud of the tyre, which wouldn't be good for grip or the puncture resistance of the tube, but as you can see the system manages to inflate a tyre from 20psi to over 50psi in about a mile. You wouldn't want to start out flat and ride your tyres full, of course, but the idea is that you'd pump up the tyre once and you'd never have to again, which would be tyre nirvana for commuters and occasional cyclists who roll their bike out of the shed twice a year with more or less exactly 20psi in the tubes.

Assuming your tyre went flat and it was possible to fix the puncture (by no means a given, since you presumably wouldn't be able to just bung another inner tube in), it also means you wouldn't have to struggle with your micro pump to get the tyre hard; just lob 30psi or so in and ride away, the tyre would do the rest.

Burying the tube within the tyre for production versions brings other problems, of course. Once it's below the surface it'll be a lot harder to make the tube compress as efficiently. But Pumptire seem confident they can make it work; they're currently looking for funding but they seemed to have cancelled their Kickstarter bid with about $18,000 (of a quarter of a million) on the clock. Whether that's because they've found funding elsewhere remains to be seen. Anyway, we'll keep tabs on the Pumptire and let you know if it gets any closer to production. In the meantime, what do you think? Can it work? Will it benefit cyclists? Discuss...

For more info, head to http://www.pumptire.com/

Dave is a founding father of road.cc, having previously worked on Cycling Plus and What Mountain Bike magazines back in the day. He also writes about e-bikes for our sister publication ebiketips. He's won three mountain bike bog snorkelling World Championships, and races at the back of the third cats.

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3 comments

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tegski | 12 years ago
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Wouldn't the pump bit be the first part to wear out? What would the longevity of the tyre be after the pump section gets a puncture…?

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WolfieSmith | 12 years ago
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The USA (God love it and Bless it) is a country that runs the mathematically nonsensical MM/DD/YY because some blokes in wigs and stockings got it wrong on the Declaration of Independence in 1776 and no one wants to admit it.

I'd give up on the 'tyre' versus 'tire' battle Dave. It's getting a little tyresome.

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andyspaceman | 12 years ago
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Pumptire, eh? Must've taken a lot of time and creative effort to come up with that one!

The name , that is.

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