The praxis bb30 bottom bracket shimano conversion 68mm okso you have bb30 pf30 or a specialized osbb frame but you need to run a shimano crank no worries our praxis works conversion bb is just what you39re looking for made to fit in either bb30 or pf30 frame the conversion bb is designed to be rock solid for a shimano hollowtech ii crank to be installed in your frame praxis bb30 bottom bracket shimano conversion 68mm features the converter works with either bb30 or pf