I've noticed the same thing, and I always think there is some level of micro-wear that is not visible to inspection, perhaps without professional inspection equipment. Such equipment in my experience (electronics product development labs) is probably a high-magnification video viewing system, coupled with a very intense illuminator. It's stunning what you can see with such a set-up. Good thing I don't have to pay for it.
This minimal level of roughness is comparred to the surface of freshly-polished high-quality races and cones, like Campys, and perhaps as well the idea of matched sets of bearing balls. These are all possibilies for a quality production environment, but perhaps not for us at home. We can buy grade 25 balls, but those are not matched, just made or selected to be within a small window, 25 microinches (er-perhaps this is micrometers? Anybody know for sure? Greg Parker perhaps?)
I think it's not likely that we at home or even in better bike shops can match the initial smoothness of a high-quality factory build.
Ken Freeman Ann Arbor, MI
-----Original Message----- From: classicrendezvous-bounces@bikelist.org [mailto:classicrendezvous-bounces@bikelist.org] On Behalf Of Bianca Pratorius Sent: Thursday, June 09, 2005 5:01 AM To: classicrendezvous@bikelist.org Subject: [CR]overhauling bearings
When overhauling bearings, I have noticed that no matter how careful I am when cleaning hubs bearings,bb, or headset, when I clean regrease and re-install and set cones etc. the result can seem a bit gritty compared to pre-overhaul "feel". It feels almost as if there is a piece of dirt in the bearing that I did not feel before. Often the feel will return to smooth after running the bearings on the road for a day. What is up with this? I don't understand the mechanism, nor do I think it is neccessary to to use new balls for every overhaul. One other related matter. What are we supposed to do with sealed cartridge bearings such as Phil Woods or old Suntour? There appears to be no way to get new grease into the bearings. This seems counter to proper maintenance rather than beneficial.
Garth Libre in Miami Fl.