Promax Direct Mount 47t Chainring BlackPromax Direct Mount 47t Chainring Black. Machined from high end aluminum Promax Direct Mount chainrings are made to be lightweight yet extremely durable to handle the torque and stress of modern BMX racing and other single ring applications. Uses SRAM 3 bolt direct mount chainring to crank interface Provides a lighter set up by elimating the use of a spider while remaining strong and stiff CNC Machined from high grade 6061 T6 series aluminum for high