campy chainline?

Brian Plaugher said:

After a repaint, I faced the bottom bracket shell on a
2001 Bianchi Eros. It had not been done before, judging
from the previous paint stuck in a groove on the right
side. After my careful work, the bottom bracket seems to
be shifted to the left. Drive side crank almost bottoms
out, while plenty of spindle is showing on the left. Is it
possible my facing removed enough material to shift the BB
significantly to the left? What is the suggested
measurement for the Campy chainline (Veloce triple)? Is
there any problem, aesthetics aside, with a not-quite-
symmetrical bottom bracket?

Not possible. Are you sure you haven't reversed the spindle?
The only result from facing the BB is to expose more left
hand cup, the right bearing cup always bottoming on its
shoulder, so the left cup sticks out farther, the spindle
being as long as it always was.

Jobst Brandt [email hidden]

On 10 Jun 2004 12:13:38 -0700, [email hidden] (Brian Plaugher)

Quoted message said:

After a repaint, I faced the bottom bracket shell on a 2001
Bianchi Eros. It had not been done before, judging from the
previous paint stuck in a groove on the right side.

Trivia: that groove marks the drive side so the frame
builder welds the shell into the frame facing the right
way. The shell could have been faced without getting that
paint out, so your frame *might* have been faced before
hand after all.

Quoted message said:

After my careful work, the bottom bracket seems to be
shifted to the left. Drive side crank almost bottoms out,

On the chain stay? Not on the bb cup, right?

Quoted message said:

while plenty of spindle is showing on the left. Is it
possible my facing removed enough material to shift the BB
significantly to the left?

Not likely, but an overzealous or inexperienced person might
get half a millimeter (if the cutter is sharp).

Quoted message said:

What is the suggested measurement for the Campy chainline
(Veloce triple)?

I think Shimano is 46mm; Campy should be close.

Quoted message said:

Is there any problem, aesthetics aside, with a not-quite-
symmetrical bottom bracket?

Been used for decades.

I think Jobst may have got it right -- if your spindle is
asymmetrical it might be turned around.

It was queried:

Quoted message said:

I think Jobst may have got it right -- if your spindle is
asymmetrical it might be turned around.

This is a cartridge bb, with the fixed cup, well, fixed to
the cartridge, so I don't see how it could be reversed. The
crank is not touching the chainstay, it is simply closer to
the bb cup on the right/drive side than on the left. If I
did in fact remove as much as a millimeter of material from
the bb shell, I suppose an equivalent spacer would reduce
the amount it sticks out on the left, and put the chainline
closer to where it is supposed to be. Brian Plaugher