What's in an Ultegra Bottom Bracket? (vs. Dura-ace)

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Phillip Stevens

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Nov 22, 2003, 5:56:52 PM11/22/03
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I've just thrown away a worn out DA BB. Served me well for many years.

I'm considering replacing it with the Ultegra BB as its cheaper and may be
better sealed. I can accept the greater weight. But before I buy, I want to
know what's inside, in terms of bearings and sealing. With the DA BB its
easy, as it can be disassembled, inspected and maintained. But, Shimano's
web page shows a two!!! piece exploded view of the Ultegra BB. Not very
revealing... to say the least.

Can anyone comment on...

a) What kind of bearings are inside the Ultegra BB (roller, ball,
combination a la DA)?
b) Whether the sealing is actually better that the DA version?
c) Any other comment on stiffness / longevity / etc...

Thanks in advance.


Arthur Harris

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Nov 22, 2003, 6:08:57 PM11/22/03
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"Phillip Stevens" wrote:
> I've just thrown away a worn out DA BB. Served me well for many years.
>
> I'm considering replacing it with the Ultegra BB as its cheaper and may be
> better sealed.
>
> a) What kind of bearings are inside the Ultegra BB (roller, ball,
> combination a la DA)?
> b) Whether the sealing is actually better that the DA version?
> c) Any other comment on stiffness / longevity / etc...

The Ultegra BB is a sealed cartridge type. There is no adjustment or
maintenance necessary (or possible). If you search the archives of rbt, you
will find an overwhelming preference for the Ultegra BB over the DA BB due
to better sealing and ease of installation. Some folks who have otherwise
"full DA" bikes, choose the Ultegra BB.

Art Harris


Mike S.

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Nov 23, 2003, 12:47:57 AM11/23/03
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"Arthur Harris" <n2...@hotmail.com> wrote in message
news:d0Svb.10696$Hb.30...@news4.srv.hcvlny.cv.net...

That would be me. I have two D/A equipped bikes with Ultegra BBs. I have
one D/A BBs in my box o' stuff, and the other is on my mtn bike till I can
find an XTR.

I ride my mtn bike MAYBE once a week, so its fine there for a bit...

The road bikes, that's another story! I can live with the extra 50g in
exchange for not worrying about the loose balls/maintenence in the D/A.

Mike
>
>


Qui si parla Campagnolo

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Nov 23, 2003, 9:28:23 AM11/23/03
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phillip-<< I've just thrown away a worn out DA BB. >><BR><BR>

<< I'm considering replacing it with the Ultegra BB as its cheaper and may be
better sealed. >><BR><BR>


'May'?- the DA wasn't really sealed at all, regardless of what it said on the
outside('sealed, cartridge').
The ultegra is a true sealed unit, not serviceable, using 1/4 round balls and a
great upgrade to DA...which is outta production anyway(altho lots still
around).


Peter Chisholm
Vecchio's Bicicletteria
1833 Pearl St.
Boulder, CO, 80302
(303)440-3535
http://www.vecchios.com
"Ruote convenzionali costruite eccezionalmente bene"

Phillip Stevens

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Nov 23, 2003, 6:34:57 PM11/23/03
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"Qui si parla Campagnolo" <vecc...@aol.com> wrote in message
news:20031123092823...@mb-m04.aol.com...

> phillip-<< I've just thrown away a worn out DA BB. >><BR><BR>
> << I'm considering replacing it with the Ultegra BB as its cheaper and may
be
> better sealed. >><BR><BR>
>
> 'May'?- the DA wasn't really sealed at all, regardless of what it said on
the
> outside('sealed, cartridge').
> The ultegra is a true sealed unit, not serviceable, using 1/4 round balls
and a
> great upgrade to DA...which is outta production anyway(altho lots still
> around).
> Peter Chisholm
> Vecchio's Bicicletteria

Thanks, that's what I'm looking for. I hear that there are two cartridge
bearing units using 1/4" round balls in the 6500 model.

Perhaps someone also knows what the difference is between the Ultegra 6500
model weighing 221grams and the DA 7710 model weighing 244 grams (both
weights according to Shimano and for 68mm English version)?

Is it just that the 7710 has different lock rings (steel vs. alu), or is
there something else going on inside?

Again, thanks in advance.


John Dacey

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Nov 23, 2003, 9:24:00 PM11/23/03
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"Alea iacta est." - Caesar

On Sun, 23 Nov 2003 23:34:57 +0000 (UTC), "Phillip Stevens"
<Phillip.Stevens(NOSPAM)@BTOpenworld.com> wrote:

>"Qui si parla Campagnolo" <vecc...@aol.com> wrote

>> The ultegra is a true sealed unit, not serviceable, using 1/4 round balls
>and a
>> great upgrade to DA...which is outta production anyway(altho lots still
>> around).

>Thanks, that's what I'm looking for. I hear that there are two cartridge


>bearing units using 1/4" round balls in the 6500 model.

I've never seen a 6500 or 7710 crankbearing cartridge destroyed to
reveal the bearing complement within, but if you're placing any
importance on ball size I'd be quite skeptical of a claim that these
units use 1/4" ones. Consider that the outside Ø of the oversize
Shimano spindles is about 26.7 mm. Add to that number the metric
equivalent of the diameter of a single 1/4" ball (~6.35 mm.) and
you've already exceeded the Ø of the entire cartridge shell (~31 mm.).
A full complement of 1/4" balls surrounding a spindle of this
dimension seems not possible with the space constraints.

>Perhaps someone also knows what the difference is between the Ultegra 6500
>model weighing 221grams and the DA 7710 model weighing 244 grams (both
>weights according to Shimano and for 68mm English version)?
>
>Is it just that the 7710 has different lock rings (steel vs. alu), or is
>there something else going on inside?

The 7710 model is available only for English bottom bracket shells.
The 6500 model is also available with Italian threaded cups. The right
hand cups of both models are steel, but the left cups of the 6500
model are aluminum. To comply with Keirin certification requirements,
the left cup of the 7710 model is also steel, and has a flange with
notches around its outside circumference to allow engagement by
traditional lockring spanners. I have sometimes thought that the
bearings of the 7710 feel fractionally smoother than the 6500, but
it's probably only in my head.

The only other difference that comes to mind is about fifteen bucks.

-------------------------------
John Dacey
Business Cycles, Miami, Florida
http://www.businesscycles.com
Now in our twenty-first year.
Our catalog of track equipment: eighth year online
-------------------------------

Qui si parla Campagnolo

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Nov 24, 2003, 9:43:49 AM11/24/03
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phillip-<< Perhaps someone also knows what the difference is between the

Ultegra 6500
model weighing 221grams and the DA 7710 model weighing 244 grams (both
weights according to Shimano and for 68mm English version)? >><BR><BR>

Could be for the triple or a track BB...both of which are sealed bearings ala
ultegra...

Peter Chisholm
Vecchio's Bicicletteria

dvt

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Nov 26, 2003, 12:08:12 PM11/26/03
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"Phillip Stevens" <Phillip.Stevens(NOSPAM)@BTOpenworld.com> wrote:
>> Thanks, that's what I'm looking for. I hear that there are two cartridge
>> bearing units using 1/4" round balls in the 6500 model.

On Sun, 23 Nov 2003 21:24:00 -0500, John Dacey <jda...@businesscycles.com>
wrote:


> I've never seen a 6500 or 7710 crankbearing cartridge destroyed to
> reveal the bearing complement within, but if you're placing any
> importance on ball size I'd be quite skeptical of a claim that these
> units use 1/4" ones. Consider that the outside Ø of the oversize
> Shimano spindles is about 26.7 mm. Add to that number the metric
> equivalent of the diameter of a single 1/4" ball (~6.35 mm.) and
> you've already exceeded the Ø of the entire cartridge shell (~31 mm.).
> A full complement of 1/4" balls surrounding a spindle of this
> dimension seems not possible with the space constraints.

Is it possible that the spindle has a smaller OD inside the cartridge? I
haven't looked at this newfangled fancy stuff, but it's possible that the
spindle is only 26.7mm on the visible portion of the BB. On the other
hand, if the spindle is hollow all the way through, you could probably
assume that the internal part is pretty close to 26.7mm diametr.

--
Dave
dvt at psu dot edu

John Dacey

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Nov 26, 2003, 2:59:40 PM11/26/03
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"Fallaces sunt rerum species." - Seneca

On Wed, 26 Nov 2003 12:08:12 -0500, dvt <dvt_...@psu.edu> wrote:

>On Sun, 23 Nov 2003 21:24:00 -0500, John Dacey <jda...@businesscycles.com>
>wrote:

>> A full complement of 1/4" balls surrounding a spindle of this


>> dimension seems not possible with the space constraints.
>
>Is it possible that the spindle has a smaller OD inside the cartridge? I
>haven't looked at this newfangled fancy stuff, but it's possible that the
>spindle is only 26.7mm on the visible portion of the BB.

Curious, I crushed the left sided of a worn 6500 cartidge yesterday to
see what lay within. The interior section of the spindle normally
obscured from view _is_ stepped down somewhat from the Ø of its
visible ends, and the race upon which the balls orbit is cut even
further into the spindle. The bearing complement on the left side was
seven 7/32" balls.


-------------------------------
John Dacey
Business Cycles, Miami, Florida

Now in our twenty-first year.

Our catalog of track equipment: eighth year online.
http://www.businesscycles.com

Phillip Stevens

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Nov 26, 2003, 8:30:53 PM11/26/03
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"John Dacey" <jda...@businesscycles.com> wrote in message
news:vq0asv4mup0sdhbm0...@4ax.com...

> "Fallaces sunt rerum species." - Seneca
> On Wed, 26 Nov 2003 12:08:12 -0500, dvt <dvt_...@psu.edu> wrote:
>
> >On Sun, 23 Nov 2003 21:24:00 -0500, John Dacey
<jda...@businesscycles.com>
> >wrote:
>
> >> A full complement of 1/4" balls surrounding a spindle of this
> >> dimension seems not possible with the space constraints.
> >
> >Is it possible that the spindle has a smaller OD inside the cartridge? I
> >haven't looked at this newfangled fancy stuff, but it's possible that the
> >spindle is only 26.7mm on the visible portion of the BB.
>
> Curious, I crushed the left sided of a worn 6500 cartidge yesterday to
> see what lay within. The interior section of the spindle normally
> obscured from view _is_ stepped down somewhat from the Ø of its
> visible ends, and the race upon which the balls orbit is cut even
> further into the spindle. The bearing complement on the left side was
> seven 7/32" balls.

Thanks for the input on this. I actually bought / installed the 6500
yesterday. It took 2min to install. Compared to the 45min I spent trying to
get the old original 7700 to spin smoothly, it was a dream.

But now I'm also curious about the definition of "cartridge bearing". I'm
not a mechanical engineer type, but I believed / assumed that a cartridge
bearing was one of those things that had an outer and inner race sealed
together in a single unit with the bearings inside, as in the DA jockey
wheel for example.

If the inner race of the 6500 is actually the spindle, then by definition
the 6500 does "NOT" actually contain cartridge bearings. Unless they class
the whole unit as a cartridge bearing of a type...?

I know its splitting hairs, but anyway I'm pleased to know more about the
inner workings of the 6500.

Thanks, Phillip


Sid

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Nov 29, 2003, 9:37:41 PM11/29/03
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I'm no expert, but I always assumed that the term "cartridge" was used to
indicate a self-contained replaceable unit. It does not necessarily imply a
"cylindrical" bearing construction.

Sid


"Phillip Stevens" <Phillip.Stevens(NOSPAM)@BTOpenworld.com> wrote in message
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