Bicycle tube. Valve: Sclaverand, French, Presta valve. Valve length: 40 mm. Removable valve. Compatible with 29", 28", and 27.5" tires. Due to its high elasticity and quality, a single tube covers a wide range of tire sizes. The quality of bicycle tubes depends on the materials used and the purity of the rubber compound. At Schwalbe, the base material is pressed through seven filters with enormous pressure before extrusion. All tubes are placed in a mold for vulcanization and then inflated. The result is uniform wall thicknesses and exceptionally high air retention. All Schwalbe tubes are inflated at the end of the manufacturing process and stored in this condition for at least 24 hours to test their air retention. In a further step, each individual tube is carefully inspected visually. A tube for various tires. Since Schwalbe tubes are extremely elastic and generally of very high quality, a single tube covers many different tire sizes. For example, Tube No. 17 works perfectly for a tire with a width of 28 mm as well as for a tire with a width of 47 mm.