1-piece forged aluminum arm/spider design for ISO square taper bottom-brackets (BB). Recommended BB: 111mm for 28.6mm seat tubes or 115.5mm for 31.8/34.9mm seat tubes *(sold separately, use Centaur/Veloce ISO versions). Triple 30/42/53t, silver Ultra-Drive Campy-10sp aluminum chainrings with ramps/pins, and steel chainring and fixing bolts. 790g @ 170mm