OCT (Open Core Technology): hollow, forged crankarm construction 1-piece forged AL-6066 alloy arm/spider design with drive-side spindle Integrated GXP-Team bottom bracket with external bearing cups: supplied with 68mm English cups (if needed separately, use TV-2123 for 70mm Italian cups, or TV-2106 for BB86) Cross38/46t (130mm BCD) hard anodized PowerGlide chainrings with ramps/pins, and alloy chainring bolts 790g @ 170mm with GXP BB set