Bicycle tubes are available with several styles of air valves. 1)Schraeder - Most common - same as is used on automobiles. 2)Presta - Narrow design used for high pressure applications. 3)Presta with extended stem - Extra long stem used on some styles of road bike wheels. Tube Size Guide Mtn Bikes - 26 x 1.25/2.25 Road Racing - 700 x 18c / Hybrid/Cross 700 x 24c Ten Speed - 27 x 1.25 / Three Speed - 26 x 1 3/8 BMX - 20 x 1.5/2.25 / Juvenile - 16 x 1.5 / 12 x 1.5 |