-The Hollowbite cranks have forged aluminum crank arms that are "hollowed out" internally at the top af the arms to reduce 30% of the weight from the original Powerbite crank arms while making them 50% stronger, new and improved steel threaded pedal inserts and an oversized 22mm chromoly spindle. Available in 175 & 180mm lengths in black only. Left and right hand drive compatible. Bottom bracket sold seperately.