Re: [CR] Campy NR Headset & Brinelling - Sacrilege

(Example: Racing:Jean Robic)

Date: Mon, 23 Nov 2009 10:14:36 -0800
From: "verktyg" <verktyg@aol.com>
To: Mark Petry <mark@petry.org>, <Classicrendezvous@bikelist.org>, <freitas1@pacbell.net>, <jamescbrown@sbcglobal.net>
References: <008c01ca6c59$b0181d60$10485820$@org>
In-Reply-To: <008c01ca6c59$b0181d60$10485820$@org>
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/wiki/Blind_men_and_an_elephant

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

Mark Petry wrote:
> When confronted with a headset that is brinelled, and you don't have the
> option of replacing the cups, mark the lower cup and the crown race with a
> sharpie so you know the "straight ahead" position, then pop them out.
> Re-install the lower cup offset 90 degrees to the right, and the crown race
> 90 degrees to the left.
>
> Now you've moved the two worn areas 180 degrees apart, and put fresh bearing
> surface in the wear position.
>
> Now repack using some serious grease with an "EP" rating. I like Wurth CV
> joint grease. Molybdenum disulfide, black, very messy. And of course use
> loose balls in the lower race. Adjust carefully - not too tight, as
> discussed above! And it's good for another 20 years.
>
> Mark Petry
> Bainbridge Island, WA