I'm new here and not an experienced mechanic. I have 7 year old Trek 7300 adult bike that has seen some miles and I am beginning to replace some components.
In my reading (Sheldon Brown etc etc) I have come across the amazing factoid (?) that Ceramic bearings in the Bottom bracket can reduce total rolling friction from 4% to 0.5 percent. I have also read that (generally) loose balls are better than balls in a retainer, AND that light oil can (or should?) be used with ceramic Bearings. Finally I have also read that there are ceramic / ceramic races and balls but also there is a hybrid of ceramic balls with steel races.
OK, here's my beginner, probably too dumb to be worthy of a polite response, question -
What happens if somebody were to replace the steel bearings with high grade equivalent ceramic bearings?
I'm a tourist, the bike can use some further replacements, so I'm willing to take a chance, but then I don't want to do something just outright stupid....
What's the experience or best conjecture on doing such a thing? Certainly this has been tried? Perhaps some shops are doing it routinely already? Conversely if a mechanic were to do this would it be considered unorthodox or an outright mistake?
Also regarding the other bearings on a bike, would this also be true for hub bearings?
Regarding rolling friction I thought perhaps I could somehow measure before and after by doing something like fastening a known weight to the crank at 3:00, letting the crank "drop" then counting the number of turns the rear wheel makes maybe 5 times and averaging - before and after. If there is a significant change in friction this should give some measure of it?
Will appreciate any comments on this whole idea of substituting ceramic for steel into existing and lightly worn races.
(My very first post ever here....)