The Howitzer Bottom Bracket System provides a bombproof bottom bracket for the extremes of Freeride and DH applications. The Howitzer BB features oversized cartridge bearings to produce a super durable external BB system. We built this system from the ground up and it is built for abuse, and yes, it can take it over and over. another benefi t to our design is agility. Time to switch your bike, but love your cranks No problem, just purchase another properly sized Howitzer BB for the new ride and remount your cranks. Howitzer a purpose built system featuring CNC machined aL-6061 cups, chromoly spindle and extreme strength thru design. 68/68G/73/73G.