TPU (thermoplastic polyurethane) is the 2026 upgrade that renders the butyl versus latex debate largely obsolete. At 20-55g, depending on model, it is 60–70% lighter than butyl, holds air for weeks rather than hours, packs down to a fraction of the size, and delivers rolling resistance close to latex. The Cyclami Superlight at £9.99 is the most accessible entry point. Tubolito, Schwalbe Aerothan, and Pirelli represent the premium end of a category that has matured significantly since TPU tubes first appeared.