Dear All, Once you start removing material from the bb shell, the process can, but is not always, irreversible. The Mavic bb is one that does not ruin the threads on your bb, but does camfer the outside thread. Obviously, this is best used on 70 mm shells (Italian) but English or French can also be used (68mm). I have used the Mavic BBs for 20 years on a couple of bikes...yes, they were team bikes, and I HAD to use them, and later, was too damn lazy and cheap to change!...and was easily able to install Campy BBs on the same bike. In other words, the camfer of the bb shell did not permanently ruin the shell for the installation of threaded cups. If, however, one has to ream the entire shell to make room for any bb sealed cartridge, then it can get dicey. I found that the Mavic BB worked better than Phil Wood...if only because the lockrings had to be tightened, rather than just placed in snug with locktite. My 2 cents... Dean Patterson Alpine, CA 91901
Ben Kamenjas <kamenjas@gmail.com> wrote: 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"
> 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
_______________________________________________
Dean Patterson Alpine, CA, USA DPCowboy
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