To add to the post by Chas. Avocet made a big deal about how hard and consistent their bearing races were. At one of the NYC shows they had an "off site" display. It included a hardness tester and other brands of parts to show how superior the Avocet stuff was. Too bad you couldn't get the Avocet stuff... (That last line is a poor joke. Avocet was known for it's delays of getting product to the market).
<freitas1@pacbell.net>; <jamescbrown@sbcglobal.net> Sent: Monday, November 23, 2009 1:14 PM Subject: Re: [CR] Campy NR Headset & Brinelling - Sacrilege
> I'm certainly going to Hades for what I'm about to say, attacking the
> sacrosanct Campagnolo...
>
> (I wish that I could get the pictures a friend took at Campagnolo, Cinelli
> and other famous component maker's shops in the early 70s. They certainly
> weren't the Sistine Chapel.)
>
> About 1974-5 we were having problems with brinelling with a lot of Campy
> headsets at our shop. We gathered up 17 new headsets and took them to a
> local machine shop and had them hardness tested. These included Campy,
> Zeus, Stronglight S5 Super Competition, P3 and V4 models, plus a number of
> other mostly entry level items including a no name Japanese one. We also
> took along several used brinelled Campy parts.
>
> The Zeus and Stronglight S5 Super Competition headsets all measured ~60Rc
> to 62Rc (Rockwell C hardness). The Stronglight P3 and V4 were a little
> lower hardness while the cheap headset measured in the high to low 50s.
>
> The hardness of the Campy headsets ranged from 48Rc to 55Rc!
>
> I've seen a lot of Campy headsets that have been used for years with no
> sign of Brinelling. I suspect that there was a window during the Bike Boom
> era where Campy's quality control was lax and they didn't check their
> beautiful looking headsets for hardness. This could have been an ongoing
> problem with soft batches slipping through from time to time.
>
> We offered to replace Campy headsets with Zeus (which we'd never seen a
> brinelling problem) but most customers didn't want to contaminate
> their all Campy bikes with a "cheap copy". Pay me now or pay me later...
>
> Please don't take my next comment as an attack as there have been some
> great suggestions made, but this thread and others about brinelling in
> Campy headsets remind me a lot of the Indian parable about a group of
> blind men describing and elephant by touching just one part... ;-)
>
> http://en.wikipedia.org/
>
> In other words, the brinelling is probably caused by a number of different
> things and if it's due to improper heat treatment then none of the great
> suggestions are going to matter.
>
> There's an easy hardness test to get a crude idea if your crown race and
> lower cup are "soft". Most hand files are ~55Rc. If you can scratch the
> bearing race area then it's under 55Rc.
>
> Bearing tracks should be 60Rc-62Rc with 58Rc the lowest acceptable
> hardness.
>
> One other comment, for years I've seen people fret over caged bearings in
> loose ball bike components. The REAL reason for caged bearings was/is for
> ease of assembly!
>
> BTW, I think that Mark's suggestion is a good temporary fix...
>
> Chas. Colerich
> Oakland, CA USA
>
>
Andrew R Stewart
Rochester, NY