Jay Dubiel wrote:
> I'm confused. The statement that Nervex are made by wrapping
> sheet metal and welding seems odd for what I have in hand and
> pictured. Beneath the chrome there is evidence of a course
> surface, pitting and heavy grinding marks which I would think
> might indicate a cast or forged piece. The inner tangs are
> 4mm thick, how does that get wrapped?
I completely understand -- it does seem hard to imagine them wrapping such thick metal around, but they (Nervex/Dubois) were masters of it.
I took some pictures of the raw crowns that make it clear that they are in fact hollow and made of sheet metal.
The first pic is of the bottoms of the crowns, and shows off the Nervex
hollowness well. The crown on the left is a Wagner, the other three
Nervex. Look at the Nervex chevrons or "epaulets", clearly seen here on
the _inside_ of the crown, showing that they are formed from sheet
rather than machined in later, like Wagner chevrons.
http://bulgier.net/
This next photo shows the tops, showing what Chas. Colerich meant about
the chevrons being pointed on the end with Wagner, but blunter or
squared-off on the Nervex:
http://bulgier.net/
Two of the three Nervex crowns in my pictures have the feature cut that matches the classic Nervex Pro lugs. Feature cut on the third Nervex is plainer, looks better with Dubois or any regular non-curlicue lugs, and this is the cut on the orange fork in the photos Jay showed us earlier.
Being hollow yet relatively large in their outside dimensions gives these crowns a very high strength-to-weight ratio. They are also relatively easy to heat up for brazing. I like 'em, but they were not popular with some framebuilders due to the relatively crude finish and the large amount of work required to make them look nice.
Mark Bulgier
Seattle WA USA