A CYCO Bikes TPU inner tube for 38 to 47mm tyres, with a 60mm Presta valve. This is the gravel and all-road size, covering everything from a fast 38mm file tread up to a 47mm adventure tyre.

Thermoplastic polyurethane replaces the butyl rubber of a conventional tube. The weight saving is most noticeable in the bigger sizes, where a butyl gravel tube is a genuinely heavy lump of rubber. TPU also holds its shape better at the low pressures gravel riding calls for, and folds down small enough to disappear into a frame bag.

Key features

• Fits 38 to 47mm tyres
• 60mm Presta valve
• Substantially lighter than a butyl tube of the same size
• Holds shape at low gravel pressures
• Packs down very small as a spare

Worth carrying even on a tubeless setup, because a gravel sidewall cut is the one thing sealant will not save you from.