How does the pumping mechanism work?
The PumpTireTM inner tube has a pumping mechanism that runs around the perimeter of the inner tube. As the wheel turns, the air in the pumping mechanism is compressed and pushed into the inner tube. When the tire returns its original shape, the pumping mechanism draws in new air from the valve stem.
When will this product be available?
We expect to launch a crowdfunding campaign toward the end of 2016.
What size tires / rims does it work with?
The first products are designed for urban commuters and will be available for 26″ and 700c rims. At a later date we will have more information about compatible tire widths and brands.
How much does it weigh?
The PumpTireTM inner tube will weigh about 100-150 grams more than a standard inner tube.
How is the end pressure determined?
The control valve is user adjustable between a given pressure range. The exact pressure range will be determined by the intended use of the rider. For example inner tubes for city bikes might be adjustable from 2.0-4.0 bar (30-60 psi) while products for road bikes would require 2-3 times as much pressure.
Is the inner tube always pumping?
No, once the tire reaches the set pressure, the pumping stops. The control system stops new air from entering the inner tube.
Does this mean I will never get a flat?
No, the PumpTireTM inner tube is not a run-flat tire. However, it does almost entirely eliminate pinch flats (snake bites). The system also incorporates a protective, anti-puncture layer that offers significant puncture resistance to sharp objects such as nails, glass, thorns, etc.