WTB Vulpine S Tire - 700 x 40 TCS Tubeless Folding BLK Light/Fast Rolling Dual DNA SGWTB Vulpine S Tire 700 x 40 TCS Tubeless Folding Black Light Fast Rolling Dual DNA SG. Vulpine S is the gravel revamp of a proven semi slick mountain tread with years of swift efficiency under its belt. The slick centerline decreases rolling resistance while its round tire profile is packed with short tightly spaced knobs to provide predictable cornering traction on hardpack terrain. The Vulpine S is the fastest tire made by WTB. Similar design as the