Friends: My experience is that chamfereing the BB shell for a Mavic BB does NOT prevent the future use of a standard BB assembly. There is still plenty of facing for a fixed cup or lockring. Many Vitus frames came chamfered for a Mavic unit, and certainly most of them got a regular BB. My '79 Raleigh Pro got Mavic-ized at some point in it's life, then I put all the Mavic goodies on a DeRosa and the Pro now sports a Stronglight sealed BB (dual adjustable cups). It got a lot of use as a commuter "back in the day" and still gets a reasonable amount of use.
Cheers from Dallas, Texas, USA, Earth! -Clyde R. (Mavic Lovin') Putman
________________________________
From: classicrendezvous-bounces@bikelist.org on behalf of Ben Kamenjas Sent: Sat 3/22/2008 7:59 PM To: classicrendezvous@bikelist.org Subject: [CR]Re: Bass-Ackward BB on Hetchins
Coolio's
My head tells me this is a perfect scenario to use one of them mavic BB's which use lockrings on both sides and needs a chamfered edge on the bb shell.
http://www.bikepro.com/
Yes it would be incorrect, irreversible and won't do well in concourse judging's but it won't come unstuck. Why risk possible damage from riding it as is? These Mavic BB's are an excellent unit (ISO tapers?) and perfect for what's needed. I'm sure some listers would have one of these for fair coin to enable this frame to be sorted and ridden.
I hope it all works out.
ciao,
Ben Kamenjas Kensington New South Wales Australia
p.s. maybe you should mount tandem cranks and a left side drive side so it's all ass backward :)
> Steve Birmingham wrote:
>
> (snipped)
> 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)
>
>
>
>
>
> 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