The shimano saint m820 crank arms with 68 and 73 mm bottom bracket gravity riding has progressed with bikes being lighter and trails getting faster saint has evolved with this providing a stiff strong and durable hollowtech ii crank set reinforced in all the ways that most extreme chainsets are not shimano saint m820 crank arms with 68 and 73 mm bottom bracket features gravity riding has progressed with bikes being lighter and trails getting faster saint has evolved with this providin