Truvativ descendant mtb crankset bb30the truvativ descendant bb30 mtb crankset is ready to perform on whatever trail youre brave enough to take on it features super stiff forged aluminium crank arms for the ultimate in power transfer and durability and a sram x sync chainring which engages with the chain in an instant and ensures it stays in place over the rough stuff features arm material forged aluminium chainring material cnc machined 7075 aluminium direct mount chainring chainring t