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

Discussion in 'Cycling Equipment' started by Phillip Stevens, Nov 22, 2003.

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  1. 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.
     
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  2. "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
     
  3. Mike S.

    Mike S. Guest

    "Arthur Harris" <[email protected]> wrote in message
    news:[email protected]...
    >
    > "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

    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
     
  4. 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"
     
  5. "Qui si parla Campagnolo" <[email protected]> wrote in message
    news:[email protected]...
    > 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.
     
  6. John Dacey

    John Dacey Guest

    "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" <[email protected]> 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
    -------------------------------
     
  7. Dvt

    Dvt Guest

    "Phillip Stevens" <Phillip.Stevens(NOSPAM)@BTOpenworld.com> wrote:
    >> Thanks, that's what I'm looking for. I hear that there are two cartri=
    dge
    >> bearing units using 1/4" round balls in the 6500 model.

    On Sun, 23 Nov 2003 21:24:00 -0500, John Dacey <[email protected]=
    m> =

    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 =D8 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 =D8 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 th= e =

    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
     
  8. John Dacey

    John Dacey Guest

    "Fallaces sunt rerum species." - Seneca On Wed, 26 Nov 2003 12:08:12 -0500, dvt
    <[email protected]> wrote:

    >On Sun, 23 Nov 2003 21:24:00 -0500, John Dacey <[email protected]> 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
     
  9. "John Dacey" <[email protected]> wrote in message
    news:[email protected]...
    > "Fallaces sunt rerum species." - Seneca On Wed, 26 Nov 2003 12:08:12 -0500, dvt
    > <[email protected]> wrote:
    >
    > >On Sun, 23 Nov 2003 21:24:00 -0500, John Dacey
    <[email protected]>
    > >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
     
  10. Sid

    Sid Guest

    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
    news:[email protected]...
    > "John Dacey" <[email protected]> wrote in message
    > news:[email protected]...
    > > "Fallaces sunt rerum species." - Seneca On Wed, 26 Nov 2003 12:08:12 -0500, dvt
    > > <[email protected]> wrote:
    > >
    > > >On Sun, 23 Nov 2003 21:24:00 -0500, John Dacey
    > <[email protected]>
    > > >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
    >
     
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