The performance gap between a clincher setup and tubeless has almost closed. The Pirelli P Zero SmarTUBES RS uses TPU (thermoplastic polyurethane) construction to arrive at 33 grams per tube — a fraction of standard butyl's weight at the same size — while delivering rolling resistance that Pirelli's lab data puts within 0.2 watts of the equivalent tubeless-with-sealant configuration. For riders who've avoided tubeless because of sealant, valve installation, or ongoing maintenance, the SmarTUBES RS removes most of that justification. One compatibility point that matters: these tubes are rated for disc brake bikes only and are not approved for rim brake use where brake track heat can degrade the TPU.

The RS designation marks a step above Pirelli's standard SmarTUBE. The updated TPU formulation delivers up to 1.5 watts of rolling resistance reduction over the base SmarTUBE and up to 24% over conventional butyl. That 12% advantage over the standard SmarTUBE comes from the compound change specifically, not from weight reduction alone. Air retention is also better than latex, which loses pressure gradually over days — the TPU holds pressure across weeks of riding without the same slow-bleed that makes latex impractical for training. The practical implication: if you're running the standard SmarTUBE and race or ride at intensity, the RS closes the remaining performance gap.

Despite the performance focus, the RS wall is 32% thicker than the original SmarTUBE, which improves puncture resistance over the thinner first-generation construction. The tube covers 26-35mm tires on 700c wheels, spanning from dedicated race tires through wider all-road widths. Presta valves come in 42mm, 60mm, and 80mm lengths to fit different rim depths: the 42mm option works on standard-depth aluminum and shallow carbon rims, while the 60mm and 80mm lengths handle mid and deep-section carbon profiles where a shorter stem won't reach for inflation.... Read More