The Challenge Criterium lives up to its name with a fast lively ride quality and outstanding grip. A supple 300 TPI carcass and open tubular construction means this handmade clincher rides just like a tubular. A dense layer beneath the tread which Challenge calls PPS prevents punctures and cuts without slowing you down. The exclusive rubber compound and chevron textured tread deliver outstanding grip in wet or dry conditions. The Challenge Criterium is available in 700c x 23mm 23-622 ISO. 87-130 recommended PSI. Folding bead. BlackBlack. This fits clincher rims only.