[CR]Re: the Hetchins with the reverse-threaded BB shell . . .

(Example: Framebuilders:Bernard Carré)

From: <emeneff@earthlink.net>
To: <classicrendezvous@bikelist.org>
Date: Thu, 27 Mar 2008 11:00:06 -0700
Subject: [CR]Re: the Hetchins with the reverse-threaded BB shell . . .

Dear Listees,

The details surrounding this frame with its odd BB shell (featuring the English threads being reversed) reminds me of a conversation I had about five years ago with the business owner of a large bike frame tubing and framebuilding supplies wholesale distributor.

I had enquired if they might have any of the older 1980's cast Cinelli BB shells kicking around, even though they were no longer listed in the catalog.

The owner laughed and told me I could go check the local garbage dump as he had recently taken three large boxes of them there (!)

These were all Cinelli BB shells that had faulty threading just like the one on the Hetchins. Reversed English, or even better - two left-hand sets of threads, or two right-hand sets of threads - and with no consistency. Sometimes even Italian on one side and English on the other (!).

In my experience problems like this are not very common, but they could possibly occur when the BB was originally machine-tapped at the foundry. As the taps are used they wear and get dull and must be changed every so often - which is conceivably where such a mistake might originate.

Because these threading mistakes are very uncommon, it is entirely conceivable that even a very skilled framebuilder might use such a BB shell in a frame assembly right through to the final tapping before realizing that there was a problem. Years ago the very common VAR BB face cutter didn't employ a threaded pilot for the facing cutter handle, so there again a builder might conceivably face a shell prior to building, but leave the BB thread tapping until the final phases of assembly.

I asked the distributor if in cases like this they were able to get a credit from Cinelli for the defective pieces. His laughter indicated how naive THAT question was.


Mike Fabian

San Francisco, CA USA