Re: [CR]overhauling bearings

(Example: Framebuilders:Brian Baylis)

From: "Earle Young" <earle.young@tds.net>
To: <classicrendezvous@bikelist.org>
References: <MONKEYFOODRqf69aZbL00002ddb@monkeyfood.nt.phred.org>
Subject: Re: [CR]overhauling bearings
Date: Thu, 9 Jun 2005 09:07:26 -0500


Ken and Garth's posts are further arguments for the hub procedure I wrote about earlier. I think balls, no matter how expensive to start with, no matter how shiny without magnification, need to be replaced with something of no less quality than Grade 25 from a single lot number. Campy matched sets are worth the price. I think that on a microscopic level, balls not only have to stay on the same side of the hub, but also be put back in the same order as they came out. And that's just too anal for me at least. By using a cleaning and lubing method that doesn't require hub overhaul, you don't disturb the balls, and never get that "just overhauled" roughness.

Earle Young, Madison, Wisc.
> 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