The race face ppf30 bottom bracket to 24mm spindle converter allows use of all race face shimano and select fsa 24mm spindles permits us of 24mm spindles in pf30 bb shell frames press fit bearing cups works like an external type headset positions the bearings externally with exactly the same wide spacing as threaded external mountain bbs precision cnc machined and anodized aluminium alloy cups more accurate durable and stable press fit interfaces than the competitors moulded plastic par