Brian Ratliff

When the industry went to external bearings, they started using industry standard, sealed, cartridge bearings. Because of the bigger diameter, the seal drag is proportionally increased, which makes it look like the bearings don't rotate as smoothly as the old cartridge BBs. But it's just seal drag. When you are turning the crank slowly, the seals create, say, 'x' N-m of torque. Because you are rotating the cranks with your hand on a workstand, 'x' N-m is a relatively large proportion of the total torque on the crank. But when you are stomping on the pedals, the seals still only exert 'x' amount of torque, but the total amount of torque on the crank is now 100 times larger, so the percentage of the total torque that 'x' exerts on the crank is now 100 times smaller.

Say seal drag was 10% of the torque on the crank when you spin the crankarms on the workstand. When you are pedaling, that same seal drag is now only 0.1% of the total torque because the actual number stayed the same while the total torque on the crank increased 100 fold. Spinning the cranks on the workstand is a poor measure of bearing drag.

So, all this talk about lower friction in ceramic bearings is just because of better seals which drag less so the cranks rotate more freely on the workstand. The only benefit ceramic bearings have is in increased wear life, because the ceramic balls are harder than any contaminants that might get into the bearings, and they will not pit and become egg shaped over time like steel bearings will. If that's worth going from a $20 bearing set to a $200 bearing set, then more power to you.