I'll add to this. British manufacturers such as Brampton and I presume BSA used this type of headset with seperate races also. The races are basically rings that fit in a curve in the lugs left by a hemispherical cutter. The upper race also fits in a curved surface in the top "race holder". The idea is that they can float and find a true alignment between the racers.
From an engineering point of view a thin annular ring is ideal for heat treating. The distortion is very small and the races can be very hard, which at least in the British headsets, they are. While people seem to look for the Bianchi rings, I have never seen a British set that showed any wear at all! And we are talking old here.The hemispherical alignment thing is also very nice from a bearing point of view (early version of Campagnolo Selform) but I wonder how well it leaves the fork steerer tube aligned with the head tube when all is said and done.
I have held in my hands Pop Brennan's hemispherical cutter for these headsets while visiting the Brennan brothers. Talk about a holy grail and a certain list member in the Seattle area owns it now!
Joe Bender-Zanoni 10 miles northwest of Irvington and Newark, NJ
> Phil Brown wrote:
> >
> > In a message dated 7/8/2 3:54:51 PM, NortonMarg@aol.com writes:
> >
> > ><< I.e. were
> > > there separate, machined races that were pressed into the
> > > integral cups? I believe this is how it's done with the
> > > best of the modern designs. >>
> > >Yes, except no need to press them in. They are a snug, not a press fit.
> >
> > This follows normal motorcycle practice which Bianchi, as a motorcycle
> > manufacturer, would have be well aware of.
>
>
> Except that Bianchi's manufacturing bicycles predates it's manufacturing
> of motorcycles by decades. Bianchi started making bikes in 1885 and
> motorcycles (without going to the books) around the early 1910s?
>
> This was bike practice way before the development of motorcycles.
>
> Chuck Schmidt
> SoPas, SoCal