new innovation in bicycle innertubes, Michelin Protek Max

The company's Protek Max tube not only contains a sealant, but is designed to compress when punctured to assist the self-sealing process.  Thanks to its uneven design, the MICHELIN Protek Max has a "compression" reaction in the event of piercing or nipping (the hole closes up naturally) whereas a classic inner tube has an "extension" reaction (balloon effect). The self plugging effect is increased by adding the sealant at the origin.

The two things you'll notice about the Protek is that it has a square cross-section, and funny little bumps on its surface. The square shape helps align it within the tire casing and against the rim well, which Michelin says eases mounting and eliminates the twisting problems that can occur with traditional sausage-shaped tubes.

When the tube is fully inflated within the tire, its textured surface causes the rubber to compress instead of expand when under pressure. This means that the internal air pressure actually closes holes off, giving the sealant a better chance at taking care of them for good.

The tubes also are claimed to hold air longer – when tested against Michelin's self-sealing AIRSTOP tube, the Protek was said to maintain proper pressure for twice the amount of time. Text from thttp://www.gizmag.com/michelin-protek-max-presses-punctures-closed/18333