So, Jobst, can I take it...

Discussion in 'Cycling Equipment' started by Mike S., Aug 26, 2003.

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  1. Mike S.

    Mike S. Guest

    ...from the lack of an answer to my question on the history of BB threadings that you don't
    know either?

    Any educated guesses from the peanut gallery as to why different BB threadings came into existence?
    (See the thread on threaded v. threadless headsets to see more of the discussion.)

    Mike
     
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  2. Jon

    Jon Guest

    As most of you know I'm sure, standards are a new thing and nobody can agree on them. Hence many
    different standards on bicycles.

    End of story. Not interesting.

    Jon

    "Mike S." <[email protected]> wrote in message news:[email protected]...
    > ...from the lack of an answer to my question on the history of BB
    threadings
    > that you don't know either?
    >
    > Any educated guesses from the peanut gallery as to why different BB threadings came into
    > existence? (See the thread on threaded v. threadless headsets to see more of the discussion.)
    >
    > Mike
     
  3. Mike Shaw asked:

    > Any educated guesses from the peanut gallery as to why different BB threadings came into
    > existence? (See the thread on threaded v. threadless headsets to see more of the discussion.)

    That's easy. Bicycles were made first, then came standardization. Originally, each major
    manufacturer had its own proprietary "standards" and then gradually they sorted themselves out by an
    evolutionary process.

    The overall winner was the standard system developed by B.S.A. (Birmingham Small Arms) in the early
    part of the last century. These standards were adopted by the British industry as B.S.C. (British
    Standard Cycle) standards, and since then, with minor tweaks they have become the international ISO
    standards used by most of the industry today.

    The value of a left-threaded fixed cup was known a _long_ time ago, but not everybody thought it was
    worth the trouble and expense.

    I've also heard it asserted that it is easier to have the threads on both sides of the bottom
    bracket perfectly aligned and concentric if they're tapped in a single continuous operation through
    from one side of the bottom bracket to the other...but I've never seen an Italian or French bottom
    bracket that showed any sign of actually being produced that way.

    English standards were naturally built to round-ish inch values, basically 1 3/8" x 24 threads per
    inch (or 26 threads per inch for the Raleigh proprietary size.)

    European manufacturers naturally used roundish metric dimensions, i.e. 35 mm for French and Swiss,
    36 mm for Italian.

    The Italian threads are the most peculiar of all. They mix units, using metric diameter with
    inch-based thread pitch (24 threads per inch.)

    I have heard that this was due to the Italians buying their lathes from England, lathes that had
    back gears for cutting inch based thread pitches only.

    Italian threads are also cut with a 55 degree tool, rather than the 60 degree thread angle used on
    metric and American threads. This harks back to the obsolete English Whitworth thread pattern
    (Whitworth was actually the first systematic system of standard threading and wrench sizes.) See:
    http://sheldonbrown.com/gloss_w.html#whitworth

    French and Swiss use 1 mm thread pitch. Swiss is the same as French except for the use of left
    threading on the right side.

    Over time, as the bicycle industry has grown more international and parts production has become
    specialized, there has been a strong trend away from the old national based and proprietary
    standards, and toward an acceptance of the international ISO standards. The old national standards
    have become extinct, except for Italian, which is still just barely keeping afloat.

    Sheldon "Actually Appeared In Howdy Doody's Peanut Gallery, Circa 1952" Brown
    +--------------------------------------------------------+
    | As far as the laws of mathematics refer to reality, | they are not certain; and as far as they
    | are certain, | they do not refer to reality. --Albert Einstein |
    +--------------------------------------------------------+ Harris Cyclery, West Newton,
    Massachusetts Phone 617-244-9772 FAX 617-244-1041 http://harriscyclery.com Hard-to-find parts
    shipped Worldwide http://captainbike.com http://sheldonbrown.com
     
  4. Mike S.

    Mike S. Guest

    "Sheldon Brown" <[email protected]> wrote in message
    news:[email protected]...
    > Mike Shaw asked:
    >
    > > Any educated guesses from the peanut gallery as to why different BB threadings came into
    > > existence? (See the thread on threaded v.
    threadless
    > > headsets to see more of the discussion.)
    >
    > That's easy. Bicycles were made first, then came standardization. Originally, each major
    > manufacturer had its own proprietary "standards" and then gradually they sorted themselves out by
    > an evolutionary process.
    >

    My big follow on question is how'd they figure out the proprietary systems in the first place? That
    the size tubing/parts they happen to have laying around?

    > The overall winner was the standard system developed by B.S.A. (Birmingham Small Arms) in the
    > early part of the last century. These standards were adopted by the British industry as B.S.C.
    > (British Standard Cycle) standards, and since then, with minor tweaks they have become the
    > international ISO standards used by most of the industry today.
    >
    > The value of a left-threaded fixed cup was known a _long_ time ago, but not everybody thought it
    > was worth the trouble and expense.
    >
    > I've also heard it asserted that it is easier to have the threads on both sides of the bottom
    > bracket perfectly aligned and concentric if they're tapped in a single continuous operation
    > through from one side of the bottom bracket to the other...but I've never seen an Italian or
    > French bottom bracket that showed any sign of actually being produced that way.
    >

    IIRC, I have, but I don't remember what bike it was on. Its been awhile, and I may be mistaken, but
    I seem to recall not being able to get the bb cup out the "right" way and had to go the whole way
    through the bb. Remember, I'm admitting that my memory may not be right here, so no flames.

    > English standards were naturally built to round-ish inch values, basically 1 3/8" x 24 threads per
    > inch (or 26 threads per inch for the Raleigh proprietary size.)
    >
    When you say round-ish, what's that mean?

    > European manufacturers naturally used roundish metric dimensions, i.e. 35 mm for French and Swiss,
    > 36 mm for Italian.
    >
    > The Italian threads are the most peculiar of all. They mix units, using metric diameter with
    > inch-based thread pitch (24 threads per inch.)
    >
    > I have heard that this was due to the Italians buying their lathes from England, lathes that had
    > back gears for cutting inch based thread pitches only.
    >
    > Italian threads are also cut with a 55 degree tool, rather than the 60 degree thread angle used on
    > metric and American threads. This harks back to the obsolete English Whitworth thread pattern
    > (Whitworth was actually the first systematic system of standard threading and wrench sizes.) See:
    > http://sheldonbrown.com/gloss_w.html#whitworth
    >
    > French and Swiss use 1 mm thread pitch. Swiss is the same as French except for the use of left
    > threading on the right side.
    >
    > Over time, as the bicycle industry has grown more international and parts production has become
    > specialized, there has been a strong trend away from the old national based and proprietary
    > standards, and toward an acceptance of the international ISO standards. The old national standards
    > have become extinct, except for Italian, which is still just barely keeping afloat.
    >
    > Sheldon "Actually Appeared In Howdy Doody's Peanut Gallery, Circa 1952" Brown
    > +--------------------------------------------------------+
    > | As far as the laws of mathematics refer to reality, | they are not certain; and as far as they
    > | are certain, | they do not refer to reality. --Albert Einstein |
    > +--------------------------------------------------------+ Harris Cyclery, West Newton,
    > Massachusetts Phone 617-244-9772 FAX 617-244-1041 http://harriscyclery.com Hard-to-find parts
    > shipped Worldwide http://captainbike.com http://sheldonbrown.com
     
  5. Fred Marx

    Fred Marx Guest

    >
    > My big follow on question is how'd they figure out the proprietary systems in the first place?
    > That the size tubing/parts they happen to have laying around?
    >
    that and what ever setup the cutting machines they bought (or made?) used.... till the guy developed
    a standard for screw threads every guy who made screws had his own way of cutting threads... he's
    mentioned in the S Brown post. The standarization of screw threads has been called a foundation of
    modern manufacturing.
     
  6. Jim Flom

    Jim Flom Guest

    >From: CaptBike

    >That's easy.

    < 400word complete international history of this stuff with Howdy Doody signature snipped >

    Easy. Right. Who is this man???

    Jim "Finally -- I'm able to see Sheldon's posts on my aol account!" Flom
     
  7. kh6zv9

    kh6zv9 Guest

    Jim Flom <[email protected]> wrote:
    :>From: CaptBike

    :>That's easy.

    : < 400word complete international history of this stuff with Howdy Doody signature snipped >

    : Easy. Right. Who is this man???

    : Jim "Finally -- I'm able to see Sheldon's posts on my aol account!" Flom

    Sheldon is "The Man" when it comes to.... well, almost anything.

    And he is a gentleman.

    --------------------------------
    Bob Masse' [email protected]
    --------------------------------
     
  8. Marketing.

    Pluss the difference in threading of english, french threads (the threads them selves are a
    different shape).

    May you have the wind at your back. And a really low gear for the hills! Chris

    Chris'Z Corner "The Website for the Common Bicyclist": http://www.geocities.com/czcorner
     
  9. Onefred

    Onefred Guest

    > > English standards were naturally built to round-ish inch values, basically 1 3/8" x 24 threads
    > > per inch (or 26 threads per inch for the Raleigh proprietary size.)
    > >
    > When you say round-ish, what's that mean?

    I thought he meant round as when you round a fraction to get a whole number. A "round-ish" figure
    of 1 3/8" as opposed to 1.667877", for example. But I really enjoyed reading Mr. Brown's post and
    want to say thanks for spending your time to give a bicycle history lesson to a bunch of
    strangers. "Thanks."

    Dave
     
  10. Chalo

    Chalo Guest

    Sheldon Brown <[email protected]> wrote:

    > The old national standards have become extinct, except for Italian, which is still just barely
    > keeping afloat.

    You forget American shells. They are alive and well, indeed smarter than ever in the fast-arising
    world of oversized BB spindles.

    I wonder why the new Phil Wood "American ISIS" and FSA "Megatech" BB standards were even proposed in
    light of this old, well established and fundamentally similar size.

    Chalo Colina
     
  11. Mike S.

    Mike S. Guest

    "onefred" <[email protected]> wrote in message news:[email protected]...
    > > > English standards were naturally built to round-ish inch values, basically 1 3/8" x 24 threads
    > > > per inch (or 26 threads per inch for the Raleigh proprietary size.)
    > > >
    > > When you say round-ish, what's that mean?
    >
    > I thought he meant round as when you round a fraction to get a whole
    number. A
    > "round-ish" figure of 1 3/8" as opposed to 1.667877", for example. But I
    really enjoyed
    > reading Mr. Brown's post and want to say thanks for spending your time to
    give a bicycle
    > history lesson to a bunch of strangers. "Thanks."
    >
    > Dave
    >
    Yeah, ditto. Thanks. Especially for doing it without trying making us look stupid 'cause we don't
    know the answer.

    Mike
     
  12. I wrote:

    >>The old national standards have become extinct, except for Italian, which is still just barely
    >>keeping afloat.

    Chalo Colina commented.

    > You forget American shells. They are alive and well, indeed smarter than ever in the fast-arising
    > world of oversized BB spindles.

    I didn't "forget" them, I was talking about threaded bottom brackets.

    I cover them at http://sheldonbrown.com/gloss_bo-z.html#bottom

    and I'm one of the few mail-order sources for this stuff that I know of, outside of the BMX world:
    http://sheldonbrown.com/harris/opc.html

    They may be alive, but they're certainly not "well." They're virtually extinct on new adult
    bikes...even newer department-store bikes almost all have ISO bottom brackets.

    > I wonder why the new Phil Wood "American ISIS" and FSA "Megatech" BB standards were even proposed
    > in light of this old, well established and fundamentally similar size.

    Similar size, but not similar type. Those new sizes are threaded, and are high precision products,
    unlike the general run of "Ashtabula" type bottom brackets. The purpose of these designs is to allow
    the use of larger cartridge bearings and larger, stronger spindles.

    I particularly like the Phil "American ISIS" and sincerely hope it catches on. However, I'm perhaps
    a bit biased, as I had some input into the design and specification of that system.

    Sheldon "Bigger Can Be Better" Brown +---------------------------------------------+
    | The nice thing about standards is that | there are so many of them to choose from. | --Andrew S.
    | Tanenbaum |
    +---------------------------------------------+ Harris Cyclery, West Newton, Massachusetts Phone
    617-244-9772 FAX 617-244-1041 http://harriscyclery.com Hard-to-find parts shipped Worldwide
    http://captainbike.com http://sheldonbrown.com
     
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