RSP Calavera Carbon Downhill Rear Wheel - 100 x 20mm - 27.5" - 28mm RimRSP Calavera Carbon Downhill Rear Wheel 100 x 20mm 27. 5" 28mm Rim This lightweight downhill Carbon rear wheel is built using a RSP Calavera Carbon rim, a chosen sealed bearing downhill specific hub and lightweight Mach1 double butted spokes. The RSP Calavera's internal profile rim offers increased air volume and traction due to lower pressure possibilities. Furthermore, these rims utilise oversized hookless bead technology for superior protection