The K40 is a reliable yet economical tire for older road bikes with 27 inch wheels. Kenda uses a thicker rubber and textured tread for great grip without slowing you down. This unique 27 inch model is extra wide for a comfortable ride on rough roads. This version of the Kenda K40 Tire is available in 27 x 1 38 inch 35-630 ISO. 90 PSI max. Wire bead. BlackGumwall.