RE:[CR]Bass-ackward BB on Hetchins

(Example: Framebuilding:Tubing:Falck)

From: "Steve Birmingham" <sbirmingham@mindspring.com>
To: <classicrendezvous@bikelist.org>
Subject: RE:[CR]Bass-ackward BB on Hetchins
Date: Sat, 22 Mar 2008 12:07:00 -0400
Thread-Index: AciMNsJ0gYiC5x4ySOObquhJdDVBUA==


Well that's good news to me! It bugged me all afternoon how I could have gotten something like that wrong. The only ideas I had were that I was working on the opposite side of the stand from what I'm used to, or that It wasn't English thread. Both poor excuses that left me feeling a bit clueless.

And that also explains why the bottom bracket wasn't long enough for a double. The long side was on the wrong side.

Most cartridge bottom brackets will probably have the same problem. I'd check with Harris cyclery to see if a Phil Wood can be reversed in the mounting rings.

I'm also not real sure just how much the direction really matters if it's properly tight. It certainly will matter if things are loose, or not lubricated, but properly lubed and tightened? I just haven't seen a backwards frame to try it on. The lockring on the right might raise eyebrows, but Once everythings sorted out it will make an excellent story. (And now you've really got to get it ready for the Lars show this year)

Steve Birmingham Lowell, Massachusetts USA

Date: Fri, 21 Mar 2008 19:12:47 -0400 From: "David Bean" <beandk@rcn.com> Subject: [CR]Bass-ackward BB on Hetchins

I decided the BB spindle on the Hetchins Italia I just received from England was too short to use with the intended crank, so I took it to Steve Birmingham's shop, where they had the special Campag Mirage spanner to remove the rings. I was a bit flummoxed because they seemed to be turning the wrong way, but maybe I'd drunk too much coffee. After a nice conversation with Steve about his cool ancient motor-pacing bike, I went home and reexamined things. Sure enough, the threading is backwards. I still have a hard time believing it.

The DRIVE side tightens up by turning it CLOCKWISE (right hand thread), the nondrive side tightens counterclockwise (left hand)! The rings are marked 1.370x24tpi. BB shell is Nervex, stamped "HET" and is 68mm wide.

How the heck could this happen? A tyro got it backwards with the taps?

And what should I do about it? (A lockring on the drive side might raise eyebrows...) Would it be best to use a sealed BB so the turning of the spindle doesn't have a direct effect on the fasteners?

David Bean
Arlington, MA USA
beandk at are-see-enn dot com