We are used to tires and inner tubes losing a little air over time. The start-up company "Pump Tire" tackled this problem back in 2011 with a self-inflating solution. At first, however, it was a tire that inflated itself while riding. However, further surveys revealed that an inner tube with the same technology met with much greater interest than a tire, as Pump Tire CEO Benjamin Krempel explains. Tires are often also an individual matter, while the choice of inner tubes is not important to most users. Stocking inner tubes is also less costly for specialist retailers than adding yet another type of tire to their range.

The inner tube, like the tire before it, uses the deformation of the tire that occurs when riding to suck in air through the valve stem. When the tire, or the inner tube, returns to its original shape, it draws in air for the next pumping cycle. Once the preset tire pressure is reached, the pump becomes inactive. The control mechanism works via the magnetic valve. Krempel explains that the system reacts very quickly, as the pump mechanism runs along the entire top of the tube. For example, you should be able to set off with one bar of air pressure in the tire. The pump-tire system then continuously inflates the tire. "Our inner tube needs around one to two kilometers for one bar of air pressure. However, this data is not clearly defined, as it can vary depending on the tire and the current pressure," continues the Pump-Tire inventor.

The hose should be ready for the market by the launch on the crowdfunding site "Kickstarter" at the beginning of 2016. Further funding will then be sought for production. Tubes for everyday use are planned for the time being. Wider versions for mountain bikes are to follow at a later date. When it comes to puncture resistance, Krempel is of the opinion that the Pump-Tire tube is more resistant than standard butyl tubes. If the function and puncture resistance prove themselves, the price of 30 to 55 euros is also justified. According to Krempel, however, the sales price has not yet been set. The exact calculation is still to be made. In addition to crowdfunding on Kickstarter, Pump Tire is also looking for further investors and potential manufacturing companies.

Pump Tire AG was founded in Zurich in 2012 and has developed through the efforts of a talented group of engineers, entrepreneurs and cycling fans. Through a grant from the Gebert Rüf Foundation, Pumptire also works with researchers from the University of Bern and ETH Zurich.

www.pumptire.com