|Behind the scenes bicycle enabler|
Cyclists don't always give ball bearings the credit they deserve. I say that because it's possible to alter many of the pieces and parts that make up a bicycle, different frame materials, different configurations, carbon fiber this, suspension or not, three wheels, one wheel, recumbent, increased bottom bracket stiffness, and so on, but there's one essential component which makes the high efficiency rolling machine possible: the ball bearing. Or at least, the bearing, since there are variations used in some parts because we can't seem to leave well enough alone out of a belief that ceramic needle bearings (I don't know if they actually exist) would yield .001% less friction on the drive-side or something. Not that there isn't oneupmanship with ball bearings themselves: once you find out that there's a grading system, and Grade 25 is possibly better and very attainable, you're headed down a slippery slope. Or at least, spinning around a slippery race.
Ball bearings: I love them. Keep them happily gooped up with grease and relatively clean, and they last a long time on a bicycle, performing their critical supporting role. This one is from the FLC project headset, before careful cleaning. Cages, or free? Hmmm.