Thermoplastic polyurethane changes the math on inner tubes. Where butyl rubber delivers predictable performance at the cost of weight and bulk, TPU achieves comparable puncture resistance while dropping roughly 70% of the mass and folding down to half the packed volume. Pirelli's Cinturato SmarTUBE X applies this material advantage with a specific focus on durability, building a tube three times thicker than their standard SmarTUBE to handle the demands of gravel, endurance, and mixed-surface riding.

The thickness increase addresses the primary concern riders have with TPU tubes: longevity under rough conditions. Standard TPU tubes excel at saving weight, but thinner walls can mean shorter service life when you're running lower pressures over chunky terrain. The SmarTUBE X trades a fraction of the weight savings for substantially more robust construction. At 146 grams, the tube still weighs less than half what a comparable butyl tube would, but the reinforced TPU walls handle the abuse that gravel and adventure riding dishes out.

Pirelli positions the Cinturato SmarTUBE X as a companion to their Cinturato tire family, though it works with any tire in its width range. The 28-40mm coverage spans road-plus widths through standard gravel setups, fitting everything from wider endurance road tires to narrower gravel options. The 60mm Presta valve accommodates most rim depths without extenders, and the black valve body maintains a clean look once installed.... Read More