Truvativ BB installation question.

[Luke]

I've just installed a Truvativ ISIS BB (model
BB-02-SPL-DH-118-68/68E/73). My BB shell width is 68mm and the Truvativ
BB was installed with the supplied spacer (to be used in lieu of the
E-type derailleurs).

Even so, the non-drive side mounting cup bottoms out (ie the BB body is
seated against the mounting cup's inner retaining ridge) before it's
integrated notched ring can contact the BB shell's surface. So, the non
drive side BB cup protudes slightly - there's a 3mmm or so gap between
the left cup's ring and the BB shell's edge. In all other respects the
installation seems fine: there's no BB play and the crankset installs
without problem.

Is this normal? Given the model designation of the BB, and the
installation instructions supplied, this BB is compatible with both 68
and 73mm shell widths.

Would a spacer between the left cup's fastening ring and the BB shell
serve any purpose?

luke

[Bill Sornson]

Luke wrote:
> I've just installed a Truvativ ISIS BB (model
> BB-02-SPL-DH-118-68/68E/73). My BB shell width is 68mm and the
> Truvativ BB was installed with the supplied spacer (to be used in
> lieu of the E-type derailleurs).
>
> Even so, the non-drive side mounting cup bottoms out (ie the BB body
> is seated against the mounting cup's inner retaining ridge) before
> it's integrated notched ring can contact the BB shell's surface. So,
> the non drive side BB cup protudes slightly - there's a 3mmm or so
> gap between the left cup's ring and the BB shell's edge. In all other
> respects the installation seems fine: there's no BB play and the
> crankset installs without problem.
>
> Is this normal? Given the model designation of the BB, and the
> installation instructions supplied, this BB is compatible with both 68
> and 73mm shell widths.
>
> Would a spacer between the left cup's fastening ring and the BB shell
> serve any purpose?

Aren't you supposed to install the left (NDS) cup first? Do you mean it
bottoms out with nothing yet in the drive-side?

Given what you describe, I'd go ahead and use a spacer to snug things up.

Bill "my TV BB developed play in three months anyway" S.

[Bill Sornson]

Luke wrote:
> I've just installed a Truvativ ISIS BB (model
> BB-02-SPL-DH-118-68/68E/73). My BB shell width is 68mm and the
> Truvativ BB was installed with the supplied spacer (to be used in
> lieu of the E-type derailleurs).
>
> Even so, the non-drive side mounting cup bottoms out (ie the BB body
> is seated against the mounting cup's inner retaining ridge) before
> it's integrated notched ring can contact the BB shell's surface. So,
> the non drive side BB cup protudes slightly - there's a 3mmm or so
> gap between the left cup's ring and the BB shell's edge. In all other
> respects the installation seems fine: there's no BB play and the
> crankset installs without problem.
>
> Is this normal? Given the model designation of the BB, and the
> installation instructions supplied, this BB is compatible with both 68
> and 73mm shell widths.
>
> Would a spacer between the left cup's fastening ring and the BB shell
> serve any purpose?

Aren't you supposed to install the left (NDS) cup first? Do you mean it
bottoms out with nothing yet in the drive-side?

Given what you describe, I'd go ahead and use a spacer to snug things up.

Bill "my TV BB developed play in three months anyway" S.

[Phil, Squid-in-Training]

> Is this normal? Given the model designation of the BB, and the
> installation instructions supplied, this BB is compatible with both 68
> and 73mm shell widths.

Yes - many bottom brackets do this, and it's especially noticeable if your
bottom bracket shell has been faced.

Some of Shimano's UN-52 or 53 BBs with plastic NDS cups have flanges that
don't butt up against the BB shell.

--
Phil, Squid-in-Training

[Phil, Squid-in-Training]

> Is this normal? Given the model designation of the BB, and the
> installation instructions supplied, this BB is compatible with both 68
> and 73mm shell widths.

Yes - many bottom brackets do this, and it's especially noticeable if your
bottom bracket shell has been faced.

Some of Shimano's UN-52 or 53 BBs with plastic NDS cups have flanges that
don't butt up against the BB shell.

--
Phil, Squid-in-Training