Thanks to innovative thermoplastic film, the Smartube from Pirelli is as light as a feather, with a volume of less than half that of a normal butyl tube. Compared to standard inner tubes, the Smartube is up to 65% lighter. The bright yellow tube also impresses in terms of puncture resistance and is twice as robust as conventional tubes. Outside the tyre, the Smartube must not be inflated above 0.5 bar. The material is less elastic than butyl, expands more from 0.5 bar and can therefore lose its shape or even burst when unmounted. Only suitable for bikes with disc brakes.