Fitting cartridge bottom brackets

[PJay]

I've notice some discrepancies between the Park website and my copy of Zinn
regarding fitting catridge BBs.

Zinn says to screw in the non-driveside cup a couple of turns, thread in the
cartridge and tighten to torque and then return to the non-driveside cup and
tighten this to torque.

The Park website says to thread the cartridge in by hand and then just
tighten the non-driveside cup, apparently this tightens again the flange on
the cartridge and tightens this up at the same time.

Which is right?

I've noticed that when I remove the cup the BB cartridge unthreads about
half way and when I tighted one or other side the other does appear to
tighten increasing the torque on the tightened side; just tightened the
non-driveside cup doesn't seem right through.

On the Shimano instructions both the cartridge and non-driveside cup are
shown as being tightened from 50-70Nm. If I tighten the driveside to torque
and then the cup I'm finding that tightening the cup then tightens the
driveside so it's well over torque nearer 100Nm (and the bearing feel as if
they're starting to bind). Having said that I've been doing it that way for
a while without problems.

What's the best method? Should I tighten the cartridge to spec. and then
just nip up the cup?

I've heard that a loose BB can damage the threads in the shell, for this to
happen would it need to be obviously loose?

Sorry, this is probably pretty simple stuff but I may build up a more
expensive frame later in the year so want to get things right and avoid
potential damage.

 

[PJay]

I've looked a bit closer at things. If I fit the cartridge (driveside) and
tighten it up to about 60Nm as per the spec. and then tighten the
non-driveside cup, tightening the cup also seems to tighten the driveside,
when the cup hits around 60Nm (or feels tight by hand) the cartridge
registers over 100Nm, this is way too much surely. The axle also feels
remarkably stiff too.

What damage can be caused by overtightening a BB, could I strip the shell
threads or crack the BB shell.

Is the tighness of the cup critical?


"PJay" <[email protected]> wrote in message
news:[email protected]...
> I've notice some discrepancies between the Park website and my copy of
> Zinn regarding fitting catridge BBs.
>
> Zinn says to screw in the non-driveside cup a couple of turns, thread in
> the cartridge and tighten to torque and then return to the non-driveside
> cup and tighten this to torque.
>
> The Park website says to thread the cartridge in by hand and then just
> tighten the non-driveside cup, apparently this tightens again the flange
> on the cartridge and tightens this up at the same time.
>
> Which is right?
>
> I've noticed that when I remove the cup the BB cartridge unthreads about
> half way and when I tighted one or other side the other does appear to
> tighten increasing the torque on the tightened side; just tightened the
> non-driveside cup doesn't seem right through.
>
> On the Shimano instructions both the cartridge and non-driveside cup are
> shown as being tightened from 50-70Nm. If I tighten the driveside to
> torque and then the cup I'm finding that tightening the cup then tightens
> the driveside so it's well over torque nearer 100Nm (and the bearing feel
> as if they're starting to bind). Having said that I've been doing it that
> way for a while without problems.
>
> What's the best method? Should I tighten the cartridge to spec. and then
> just nip up the cup?
>
> I've heard that a loose BB can damage the threads in the shell, for this
> to happen would it need to be obviously loose?
>
> Sorry, this is probably pretty simple stuff but I may build up a more
> expensive frame later in the year so want to get things right and avoid
> potential damage.
>
>

 

[Qui si parla Campagnolo]

On May 4, 9:14 am, "PJay" <[email protected]> wrote:
> I've looked a bit closer at things. If I fit the cartridge (driveside) and
> tighten it up to about 60Nm as per the spec. and then tighten the
> non-driveside cup, tightening the cup also seems to tighten the driveside,
> when the cup hits around 60Nm (or feels tight by hand) the cartridge
> registers over 100Nm, this is way too much surely. The axle also feels
> remarkably stiff too.
>
> What damage can be caused by overtightening a BB, could I strip the shell
> threads or crack the BB shell.
>
> Is the tighness of the cup critical?
>
> "PJay" <[email protected]> wrote in message
>
> news:[email protected]...
>
> > I've notice some discrepancies between the Park website and my copy of
> > Zinn regarding fitting catridge BBs.
>
> > Zinn says to screw in the non-driveside cup a couple of turns, thread in
> > the cartridge and tighten to torque and then return to the non-driveside
> > cup and tighten this to torque.
>
> > The Park website says to thread the cartridge in by hand and then just
> > tighten the non-driveside cup, apparently this tightens again the flange
> > on the cartridge and tightens this up at the same time.
>
> > Which is right?
>
> > I've noticed that when I remove the cup the BB cartridge unthreads about
> > half way and when I tighted one or other side the other does appear to
> > tighten increasing the torque on the tightened side; just tightened the
> > non-driveside cup doesn't seem right through.
>
> > On the Shimano instructions both the cartridge and non-driveside cup are
> > shown as being tightened from 50-70Nm. If I tighten the driveside to
> > torque and then the cup I'm finding that tightening the cup then tightens
> > the driveside so it's well over torque nearer 100Nm (and the bearing feel
> > as if they're starting to bind). Having said that I've been doing it that
> > way for a while without problems.
>
> > What's the best method? Should I tighten the cartridge to spec. and then
> > just nip up the cup?
>
> > I've heard that a loose BB can damage the threads in the shell, for this
> > to happen would it need to be obviously loose?
>
> > Sorry, this is probably pretty simple stuff but I may build up a more
> > expensive frame later in the year so want to get things right and avoid
> > potential damage.

If tightening the BB cups makes the spindle too tight, need to prep
the BB shell, chase and face.

 

[PJay]

Oddly I've found that axle stiffness doesn't occur at all if I replace the
resin adapter with an alloy one, no idea why this works though.

"Qui si parla Campagnolo" <[email protected]> wrote in message
news:[email protected]...
> On May 4, 9:14 am, "PJay" <[email protected]> wrote:
>> I've looked a bit closer at things. If I fit the cartridge (driveside)
>> and
>> tighten it up to about 60Nm as per the spec. and then tighten the
>> non-driveside cup, tightening the cup also seems to tighten the
>> driveside,
>> when the cup hits around 60Nm (or feels tight by hand) the cartridge
>> registers over 100Nm, this is way too much surely. The axle also feels
>> remarkably stiff too.
>>
>> What damage can be caused by overtightening a BB, could I strip the shell
>> threads or crack the BB shell.
>>
>> Is the tighness of the cup critical?
>>
>> "PJay" <[email protected]> wrote in message
>>
>> news:[email protected]...
>>
>> > I've notice some discrepancies between the Park website and my copy of
>> > Zinn regarding fitting catridge BBs.
>>
>> > Zinn says to screw in the non-driveside cup a couple of turns, thread
>> > in
>> > the cartridge and tighten to torque and then return to the
>> > non-driveside
>> > cup and tighten this to torque.
>>
>> > The Park website says to thread the cartridge in by hand and then just
>> > tighten the non-driveside cup, apparently this tightens again the
>> > flange
>> > on the cartridge and tightens this up at the same time.
>>
>> > Which is right?
>>
>> > I've noticed that when I remove the cup the BB cartridge unthreads
>> > about
>> > half way and when I tighted one or other side the other does appear to
>> > tighten increasing the torque on the tightened side; just tightened
>> > the
>> > non-driveside cup doesn't seem right through.
>>
>> > On the Shimano instructions both the cartridge and non-driveside cup
>> > are
>> > shown as being tightened from 50-70Nm. If I tighten the driveside to
>> > torque and then the cup I'm finding that tightening the cup then
>> > tightens
>> > the driveside so it's well over torque nearer 100Nm (and the bearing
>> > feel
>> > as if they're starting to bind). Having said that I've been doing it
>> > that
>> > way for a while without problems.
>>
>> > What's the best method? Should I tighten the cartridge to spec. and
>> > then
>> > just nip up the cup?
>>
>> > I've heard that a loose BB can damage the threads in the shell, for
>> > this
>> > to happen would it need to be obviously loose?
>>
>> > Sorry, this is probably pretty simple stuff but I may build up a more
>> > expensive frame later in the year so want to get things right and avoid
>> > potential damage.
>
> If tightening the BB cups makes the spindle too tight, need to prep
> the BB shell, chase and face.
>
>