Those big chunky tyres used on mountain bikes don't just help plough through rough terrain and absorb shocks. When under-inflated, they also have a much larger footprint for extra grip on uneven surfaces -- but there's a tradeoff.
When an impact compresses the inner tube too far it can cause what's known as snake bite punctures, an all too common problem faced by bikers that a new double-chambered tyre might solve.
As the double valves indicate, the new ture -- jointly developed by Schwalbe and bike accessory maker Syntace -- features a chamber next to the rim which can be pumped up to higher pressures, preventing it from squishing to the point of puncturing. And it sits next to an outer chamber that can be inflated to lower pressures, so it's able to spread out for improved traction and compress better over bumpy terrain.
The tyre -- which is still being perfected and will hopefully be available later this year -- is an improvement to the tubeless design that's often used in off-road wheels. Previous tubeless tyres could be inflated to low pressures with less of a risk of impact punctures, but it also increased the chances of the tyre popping off the rim. Since the higher-pressure inner chamber hugs the rim with this new design, that shouldn't be a problem here. [Schwalbe via Gizmag via BikeRadar]