"correct" bb spindle length?
joseph.sa...@gmail.com
I'm building up a bike for a buddy and we have an FSA Carbon Pro Team
Issue crankset. Square taper, the kind with an alloy (not carbon)
spider. What length BB spindle would be ideal? I've got an 111mm Campy
BB. It's new so I don't want to mount it just to check. Will this work?
Thanks!
Joseph
russell...@yahoo.com
I'm sure you have read it here before, but I'll repeat it anyway.
Shimano and Campagnolo use different sized tapers on their square
bottom brackets. So mixing them may not be recommended. I would not
do it, but others seem to love doing it.
I think FSA made its cranks in the square taper size specifically for
Campagnolo bottom brackets. I think. They may have also made them for
square taper Shimano bottom brackets. If your crank is specifically
for Campagnolo square taper bottom brackets, then the length would be
102mm for a double. Same length as Campagnolo uses on its Record and
Chorus double cranks. And along with Phil Wood, about the only
somewhat widely distributed makers of Campagnolo tapered bottom
brackets.
Your 111mm Campagnolo bottom bracket is either a triple length from the
Record/Chorus level. Or a double/triple from the Centaur/Veloce/Mirage
level. Same length but one of these is asymmetric and the other is
symmetrical. So they are not really interchangeable. I doubt if your
111mm Campagnolo bottom bracket is the right one for this FSA crank.
I'm kind of assuming FSA would have made its double crank for the
higher end Record/Chorus bottom brackets instead of the cheaper
Centaur/Veloce/Mirage bottom brackets.
You probably need to contact FSA and figure out whether your crank is
for Shimano or Campagnolo taper bottom brackets. Then they can also
tell you what length to get. They sell square taper bottom brackets in
the Shimano taper.
joseph.sa...@gmail.com
Groan... My buddy insisted it was going to save him lots of money and
hassle to buy his parts when on vacation in Denmark. When he got home
and we opened the box he had the wrong crankset and wrong bb. Square
taper FSA? What a pain. And his box of goodies had an Octalink DA bb!
And of course he "needs" his bike by the weekend. So I have to figure
out what sort of bb he needs, and get one with Italian threads
yesterday.
What do you suppose using a 111mm symmetrical AC-H bb would do? It
would stick the chainrings 4.5mm further out than they should be,
right? (Assuming 102 Campy is correct.)
Joseph
russell...@yahoo.com
Assuming the crankset is Campagnolo tapered, then it would just put the
chainline out 4.5mm on each side. Not a big to do. I am pretty sure
the 102mm Campagnolo bottom bracket is symmetrical. Just the 111mm
Record/Chorus for the triple is asymmetrical. I think.
If the crank is Shimano tapered, then the crankset will slide a bit
further onto the spindle since the Campagnolo taper starts off smaller
at the end than the Shimano taper. So your chainline would be less
than 4.5mm too wide on each side. I'll let others comment on whether
having a too small bottom bracket actually causes problems to the crank
itself.
Checking the FSA website it looks like they make their carbon/titanium
square taper bottom bracket in both ISO (Campagnolo) and JIS (Shimano).
ISO is only 103 and 111, Campagnolo lengths naturally. JIS is various
lengths. Italian threading and ISO is only available in the
carbon/titanium model. So based on what FSA sells for bottom brackets,
I'm not sure you can definitely tell what taper your square taper FSA
crank has.
Paul Kopit
>Checking the FSA website it looks like they make their carbon/titanium
>square taper bottom bracket in both ISO (Campagnolo) and JIS (Shimano).
> ISO is only 103 and 111, Campagnolo lengths naturally. JIS is various
>lengths. Italian threading and ISO is only available in the
>carbon/titanium model. So based on what FSA sells for bottom brackets,
>I'm not sure you can definitely tell what taper your square taper FSA
>crank has.
The ISO FSA crank I had was marked ISO near the square taper hole.
joseph.sa...@gmail.com
As is this one. So the 111 symmetrical one puts the chainline off by
4.5mm. Should I worry about that? Or just build it.
Joseph
russell...@yahoo.com
To get it built by this weekend your options are
1. Order a Campagnolo Record/Chorus or FSA 102/103 mm length ISO
(Campagnolo) square taper bottom bracket and have it shipped overnight.
Not cheap but I would bet about anything it is the right bottom
bracket length and taper. And when the job is done, its done right and
nothing to change again.
2. Put on the 111mm AC-H you currently have. Have your friend ride it
and decide if he can tell any difference with the increased chain line.
Likely not. Have your friend give you $20 for the AC-H and order a
new one for yourself.
3. Put the 111mm AC-H bottom bracket on temporarily and order by cheap
delivery a Record/Chorus or FSA 102/103 mm ISO bottom bracket. Change
bottom brackets when the correct one arrives. Not a huge deal changing
bottom brackets.
joseph.sa...@gmail.com
We were going to go with option 3, but an AC-H should be faced on both
sides of the bb shell. This frame is only faced on the right side, and
I don't have a facer. It would probably work fine for a few days, but
you never know. It's his bike, so he gets to drive to Oslo (150km) to
get a Record one tomorrow if he wants his bike ready for the weekend.
It's nice to know all the specifics about square-taper (ISO vs JIS) etc
that I was not aware of before. This knowledge will hopefully save me
from problems in the future.
Joseph