Re: [CR]Procedure for removing pits from pressed hub bearing races?

(Example: Books:Ron Kitching)

Date: Wed, 24 Oct 2007 18:34:46 -0700 (PDT)
From: "Kenneth Freeman" <ken4bikes@att.net>
Subject: Re: [CR]Procedure for removing pits from pressed hub bearing races?
To: rapidfire10ring@hotmail.com, Mitch Harris <mitch.harris@gmail.com>, "Ted E. Baer" <wickedsky@sbcglobal.net>
cc: classicrendezvous@bikelist.org


Bruce, especially in light of the chemical issues Tom Sanders has raised, t his is a much more preferable and gentler process than I suggested, and it has early feedback to see if you're on the right track. Thanks!

Ken F
reeman
Ann Arbor, MI USA


----- Original Message ----
From: bruc


e thomson <masi3v4me@yahoo.com> To: Kenneth Freeman <ken4bikes@att.net>; Mitch Harris <mitch.harris@gmail.com>; Ted E. Baer <wickedsky@sbcglobal.net
> Cc: classicrendezvous@bikelist.org Sent: Wednesday, October 24, 2007 1:45:33 PM Subject: RE: [CR]Procedure for removing pits from pressed hub bearing races?

My procedure for the process is a bit different. I hav e had built wheels that have had gritty hubs and a few pits. I first inspe ct the bearings to see if any in particular are cracked or have lost their chrome plating. I discard those. Replace with another suitable size bearing and mix a metal polish with the grease. Yup, a paste with an abrasive. I ride for a number of rides, remove the wheels and 'feel' for the improv ement. After the gritty sound has left and the spin has less resistance I replace all the ball bearings with new and of course replace all of the gre ase. An inspection of the cones and bearing races will show a remarkable i mprovement and smoothness. BT

Kenneth Freeman <ken4bikes@att.net> wrote: Yes, I also heard of this as a way of making a lower-grade hub, li ke a Maillard or Normandy, into a good roller like a Campy Record.

I would think you could chuck the axle in a slow drill or electric screwdr iver and spin it at 60 RPM max to accelerate the process. You don't want to go too fast, because the cutting action could cause overheating and da mage the surfaces. Wheel rate at 15 mph is around 3 revolutions per secon d, so to accelerate maybe 3 times, use a drill speed of 10 rev/second or 600 rev/minute maximum. I don't really know if its safe to go faster, I j ust know its bad to go too fast in cutting operations.

Assume you ride 100 miles a week and the "old standard" is to ride 3 (a few) weeks, run the drill for 6 hours.

I have not tested this, just suggesting an acce lerated way to do this in the shop.

Maybe a more aggressive cutting paste than Simichrome or rouge would work to reduce the race surface to t he level of the pits. Then if you follow this up with rouge polishing, co uld it be a good bearing surface? How does the depth of cut relate to the case hardening depth?

Ken Freeman Ann Arbor, MI

-----Original Message----- From: classicrendezvous-bounces@bikelist.org [mailto:clas sicrendezvous-bounces@bikelist.org] On Behalf Of Mitch Harris Sent: Wedne sday, October 24, 2007 3:11 AM To: Ted E. Baer Cc: classicrendezvous@bi kelist.org Subject: Re: [CR]Procedure for removing pits from pressed hub bearing races?

I also did this a few times about two and a half decade s ago, but like Drew says, it wasn't to fix a pitted hub, but to try to g et a middling hub to run as smoothly as a new campy hub. We used jewlers' rouge. We didn't hesitate to ride a few weeks this way. Normal bearing a djustment. Never heard of this helping with pitted races, but if it works let us know.

Mitch Harris Little Rock Canyon, UT ________________ _______________________________ Classicrendezvous mailing list Classicr endezvous@bikelist.org http://www.bikelist.org/mailman/listinfo/classicre ndezvous

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Bruce Thomson Spoka ne WA 99204 (509) 747 4314 Masi3v4me@yahoo.com

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