Spinning and Grinning This rock-solid, durable performer is everything you need in a press-fit 24mm bottom bracket and nothing more. Roll on...and on...and on. In A Sea Of Bearings These little buggers can make a huge difference, so we've made sure our double row custom retainer bearings are super durable and up for the long run. Close Enough Won't Cut It These precision steel cup are coated for corrosion resistance, and CNC-ground surfaces of this bottom bracket provide an exact, perfectly quiet fit in your frame. Weather, Or Not All RF bottom brackets come with an inner plastic sleeve to keep the elements out and include all appropriate spacers to ensure a versatile fit.