Re: [CR] British BB oil hole thread?


Example: Framebuilders:Dario Pegoretti

Date: Sat, 14 Feb 2009 13:51:34 -0500
To: <classicrendezvous@bikelist.org>
From: John Betmanis <johnb@oxford.net>
In-Reply-To: <49970AC8.7000802@gmail.com>
Subject: Re: [CR] British BB oil hole thread?


At 10:17 AM 14/02/2009 -0800, Jack Fortune wrote:
>Data point: When I had my 1964 Jack Taylor repainted, I had to re-tap the hole
>for the grease fitting in the bottom of the bb. Being fairly ignorant of all of
>the many British standards, I simply matched the thread on my US gauge and
>bought a #10 x 32 TPI tap. This seemed to match the original size perfectly.

Yes, 10-32 would be close. However, when I tried a 10-32 screw in a BB with the original thread, it only went in a short distance. Perhaps the original nipple would go into a 10-32 tapped hole okay because it only has a short thread. Also, if you purchase a standard 90° or 45° grease fitting from an auto parts store, you'll find that if you unscrew the angled nipple part, it has a 10-32 thread. Modern nipples are a bit bigger than those found on old British bikes and I doubt that a grease chuck would fit on them the way they're positioned on the BB, but you probably wouldn't grease your BB that way anyway. It's just that an actual nipple, even if it isn't the correct one, would look more "original" than a screw head.

John Betmanis
Woodstock, Ontario
Canada