Ritchey WCS Trail Stem - 60mm 31.8 Clamp +/-0 1 1/8" Aluminum BlatteRitchey WCS Trail Stem 60mm 31. 8 Clamp + 0 1 1 8" Aluminum Blatte. The Ritchey WCS Trail Stem was first designed for longer travel mountain bikes and wider bars. It uses a 220 degree clamp that fits a wider variety of riser bar bends and still packs a dramatic increase in stiffness and strength over competitors designs. 3D Forged 2014 alloy provides superior strength while remaining lightweight Extra wide bar clamp for increased stiffness; fits most