I think you could resolve this hardening question by taking a dead race or cup and cutting it, then doing hardness tests on the now-exposed inner metal. Assume here you;'ve already done hardness tests on the unworn portion of the race.
On Tue, Nov 24, 2009 at 1:53 AM, Brian Samson <brsamson@telus.net> wrote:
> I've worked out a method of re-grinding brinelled headset races using a
> lathe and a small curved grinding stone mounted in a Dremel tool. It's a
> bit tedious because the Dremel tool has limited power, but the results seem
> good. I grind the crown race while it is mounted on the fork, which gives a
> very true finished product. I'm not sure whether the races are
> surface-hardened (anybody know?), and whether I could grind through the hard
> layer into the base metal. So far I don't get the impression of grinding
> through into a softer layer. I haven't yet disassembled or re-inspected the
> two or three I've done so far, and I haven't put many miles on any of them
> yet, but so far I haven't noticed any indexing.
>
> So if any of you have brinelled headsets you would like to sell me cheap,
> let me know!
>
> Brian Samson
> Vancouver, BC, Canada.
>
>
>
> On 23-Nov-09, at 2:53 AM, Ken Freeman wrote:
>
>
>> I've often wished some skilled CR member could re-machine NR races.
>>
>>
> _______________________________________________
>
--
Ken Freeman
Ann Arbor, MI USA