Re: [CR]RE: 4 th Bottom bracket?


Example: Framebuilders

Date: Thu, 16 May 2002 20:44:38 -0700 (PDT)
From: Fred Rafael Rednor <fred_rednor@yahoo.com>
Subject: Re: [CR]RE: 4 th Bottom bracket?
To: Huemax@aol.com, DTSHIFTER@aol.com, classicrendezvous@bikelist.org
In-Reply-To: <32.2707b34b.2a15cf3c@aol.com>


Ken, Your message was confusing to me - but here's a synopsis of the differences between French and Swiss bottom bracket threading. French threads: - 35 mm x 1mm (1.378" x 25.4 TPI), right-hand threading on both sides. Swiss threads: - 35 mm x 1mm (1.378" x 25.4 TPI), left-hand threading on the fixed cup and right hand threading on the adjustable cup.

Swiss threaded BBs can be diabolical: because of the left hand threaded fixed cup, it's easy to be fooled into thinking that the BB has English threads. (I nearly made this mistake on my '84 Peugeot.) On the other hand, because of the 35mm diameter and the fact that the adjustable cup is the same, it's easy to be fooled into thinking the BB has French threads.

Swiss threaded BBs were often found on French bikes, plus I've seen them on a couple of Spanish frames. I've only worked on a few Swiss bikes but none of them had Swiss threaded BBs. "Interesting"...
     Regards,
     Fred Rednor - Arlington, Virginia