I'd considered reporting on Goodyear's self-inflating tire for automobiles when the Times mentioned it a couple weeks ago, but I ultimately decided not to, given the lack of images and (confidential) information. Still, the tidbits that Goodyear did divulge piqued my interest: "While the technology is complex, the idea behind the A.M.T. system is relatively simple and powered by the tire itself as it rolls down the road," said Jean-Claude Kihn, a Goodyear executive, in a prepared statement. The manufacturer did not disclose any further details about the concept's operating principle.
Self-regulating tire-pressure systems are not new. Such systems are common sights on the undersides of tractor-trailers, but they depend on the harmonious operation of various peripheral devices, including air pumps, filters and pressure valves. The Goodyear concept houses the tire-pressure regulation equipment, including a small pump mechanism, inside the tire itself.
This is precisely what a San Francisco-based startup called PumpTire has just created for the increasingly popular urban conveyance known as the bicycle. Founder Benjamin Krempel and his international team of cycling enthusiasts invite you to "imagine taking your bicycle out of the garage and never having to fill up the tires or even check the pressure. Or imagine yourself being able to change your tire pressure on-the-fly with a simple adjustment from the handlebars. PumpTire is developing both of these systems."
The PumpTire operates on what sounds like a similar principle to Goodyear's otherwise top-secret auto tire, drawing air into a "lumen" (see video below) through a one-way valve while the wheel is rolling. The rim-mounted valve—which comes in the standard presta and schrader variations—detects the pressure and stops when the built-in inner tube is at a certain psi. "The self-inflating, self-adjusting technology is incorporated directly into the tire and is compatible with current rims, making it a simple addition to any bicycle."If the Kickstarter campaign reaches full funding, two versions will be available at launch: a 26” × 1.6” "City Cruiser" tire for casual cyclists and a 700c × 28mm "City Pro" high-performance tire for the more serious commuter, which go up to a preset 65 psi and adjustable 65-95 psi, respectively.
Krempel and his team acknowledge that the $250,000 they're seeking is quite a hefty sum —they have yet to develop the technology for self-Kickstarting product design—and lest potential backers deem this goal to be inflated, the money will go towards four purposes:
1. Completing the engineering design. This will require us to work with vendors and engineering firms to find the right materials and processes to make the product robust and lightweight. Although we have various working prototypes, we'll need money to make sure each part of the system works properly.
2. Testing. Once we've completed the production design we will build and test prototypes to see what we got right and what needs additional engineering.
3. Purchasing tooling. We will need to have molds built for each type of tire as well as the lumen and the individual pieces in the control valve assemblies.
4. Purchasing materials. And finally, we need to pay for the materials and components that go into each tire assembly.
Hopefully some of that money can go towards producing a better Kickstarter video (and maybe some flashier images) too...
Curious to learn more about founder Benjamin Krempel, I was surprised to learn that his day job is the CEO of a medical device company. I wonder if his experience in the professional domain has informed the technology behind the PumpTire.
Commenters on Gizmag (where I came across the product, via Marty from Geekhouse) question their performance—though I would say that the PumpTire isn't intended to compete with the likes of Vittoria, Continental, Maxxis, etc.—and include a link to another interesting self-inflating tire design.