Hope pro 4 mtb rear hub single speedtrialshope hubs have proven their reputation for bulletproof quality time and time again thats why the hope pro 4 trialssingle speed hub has become the rear hub of choice for many of the best trials riders in the world features4 pawl ratchet with 88 tooth engagement 4 1sealed stainless steel cartridge bearingsmachined from forged 2014 t6 aluminium billetstandard 6 bolt disc fittinglarger spoke flange to enable stiffer wheel buildsunsurpassed reliabil