Machined from a solid extruded block vs. Forging

Discussion in 'Cycling Equipment' started by Llatikcuf, Jan 25, 2006.

  1. Llatikcuf

    Llatikcuf Guest

    Talked to the people at Thomson today about their stems, he said they
    were machined from a solid extruded block and related the idea of clay
    being pushed through a small opening. How does extruding a solid block
    of aluminum compare in strength and fatigue resistance to the item
    being forged?

    -Nate
     
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  2. Werehatrack

    Werehatrack Guest

    On 25 Jan 2006 15:31:37 -0800, "Llatikcuf" <[email protected]>
    wrote:

    >Talked to the people at Thomson today about their stems, he said they
    >were machined from a solid extruded block and related the idea of clay
    >being pushed through a small opening. How does extruding a solid block
    >of aluminum compare in strength and fatigue resistance to the item
    >being forged?


    Forging shapes the grain of the material to better align it with the
    surface of, and presumably the stresses applied to, the item.
    Machining the item from an extrusion puts all the grain in one
    direction, some of it perpendicular to the machined surface.
    Thomson's choice of method is still superior to making the part from a
    casting, however, and their reputation is pretty good. Since you don't
    have the option of getting a Thomson stem that's forged, the important
    question is not whether their choice of method is the best possible,
    but rather if it's adequate for the task.
    --
    Typoes are a feature, not a bug.
    Some gardening required to reply via email.
    Words processed in a facility that contains nuts.
     
  3. Llatikcuf

    Llatikcuf Guest

    Werehatrack wrote:
    > Thomson's choice of method is still superior to making the part from a
    > casting, however, and their reputation is pretty good. Since you don't
    > have the option of getting a Thomson stem that's forged, the important
    > question is not whether their choice of method is the best possible,
    > but rather if it's adequate for the task.


    Indeed, yet one is left to wonder why Thomson decided to do it this
    way. Do they believe it's stronger than it's forged competitor?

    -Nate
     
  4. philcycles

    philcycles Guest

    Llatikcuf wrote:
    > Werehatrack wrote:
    > > Thomson's choice of method is still superior to making the part from a
    > > casting, however, and their reputation is pretty good. Since you don't
    > > have the option of getting a Thomson stem that's forged, the important
    > > question is not whether their choice of method is the best possible,
    > > but rather if it's adequate for the task.

    >
    > Indeed, yet one is left to wonder why Thomson decided to do it this
    > way. Do they believe it's stronger than it's forged competitor?
    >
    > -Nate


    Cost. It's cheaper than making forgiing dies.
    Phil brown
     
  5. Werehatrack

    Werehatrack Guest

    On 25 Jan 2006 17:44:39 -0800, "philcycles" <[email protected]>
    wrote:

    >
    >Llatikcuf wrote:
    >> Werehatrack wrote:
    >> > Thomson's choice of method is still superior to making the part from a
    >> > casting, however, and their reputation is pretty good. Since you don't
    >> > have the option of getting a Thomson stem that's forged, the important
    >> > question is not whether their choice of method is the best possible,
    >> > but rather if it's adequate for the task.

    >>
    >> Indeed, yet one is left to wonder why Thomson decided to do it this
    >> way. Do they believe it's stronger than it's forged competitor?
    >>
    >> -Nate

    >
    >Cost. It's cheaper than making forgiing dies.
    >Phil brown


    And, to be honest, it's probably adequate. There is such a thing as
    engineering overkill; Mecedes-Benz is infamous for it.
    --
    Typoes are a feature, not a bug.
    Some gardening required to reply via email.
    Words processed in a facility that contains nuts.
     
  6. jim beam

    jim beam Guest

    philcycles wrote:
    > Llatikcuf wrote:
    >
    >>Werehatrack wrote:
    >>
    >>>Thomson's choice of method is still superior to making the part from a
    >>>casting, however, and their reputation is pretty good. Since you don't
    >>>have the option of getting a Thomson stem that's forged, the important
    >>>question is not whether their choice of method is the best possible,
    >>>but rather if it's adequate for the task.

    >>
    >>Indeed, yet one is left to wonder why Thomson decided to do it this
    >>way. Do they believe it's stronger than it's forged competitor?
    >>
    >>-Nate

    >
    >
    > Cost. It's cheaper than making forgiing dies.
    > Phil brown
    >

    for small quantity, yes. for big productions runs, it works the other
    way. forged is usually better.
     
  7. In article <[email protected]>, Werehatrack
    ([email protected]) wrote:

    > And, to be honest, it's probably adequate. There is such a thing as
    > engineering overkill; Mecedes-Benz is infamous for it.


    s/is/was They decided that it was costing too much and started making
    substantial chunks of their motorcars from cheese. They started to
    exhibit un-Mercedes-like tendencies, like breaking down and wearing out
    when they'd not even done 200,000 km!

    To say that the collected taxi drivers of the German-speaking world were
    incandescent would be something of an understatement. I am given to
    understand that the latest E-Class is once more milled from solid.

    --
    Dave Larrington - <http://www.legslarry.beerdrinkers.co.uk/>
    Pepperoni and green peppers, mushrooms, olives, chives!
     
  8. philcycles wrote:
    > Llatikcuf wrote:
    > > Werehatrack wrote:
    > > > Thomson's choice of method is still superior to making the part from a
    > > > casting, however, and their reputation is pretty good. Since you don't
    > > > have the option of getting a Thomson stem that's forged, the important
    > > > question is not whether their choice of method is the best possible,
    > > > but rather if it's adequate for the task.

    > >
    > > Indeed, yet one is left to wonder why Thomson decided to do it this
    > > way. Do they believe it's stronger than it's forged competitor?
    > >
    > > -Nate

    >
    > Cost. It's cheaper than making forgiing dies.
    > Phil brown


    Yep. And Phil Wood and Chris King and other boutique makers use the
    fabulous marketing letters CNC in their advertising print and people
    worship them. Never realizing boutique makers use CNC machining and
    cartridge bearings in their products because they do not have the
    ability to use forging and cup and cone bearings. Its a great
    marketing coup for the boutique makers to convince customers that the
    cheaper and easier CNC machining is superior to forging.
     
  9. Scott Gordo

    Scott Gordo Guest

    Llatikcuf wrote:
    > Talked to the people at Thomson today about their stems, he said they
    > were machined from a solid extruded block and related the idea of clay
    > being pushed through a small opening. How does extruding a solid block
    > of aluminum compare in strength and fatigue resistance to the item
    > being forged?
    >
    > -Nate


    That's interesting. I'd figured that it was forged and then milled
    down. Doesn't that seem like the ideal solution?

    /s
     
  10. Even more fun is that so few people know exactly what CNC refers to..
    last I checked a CNC hobby mill or lathe from Sherline was under $2000.

    You can CNC machine your own hubs, headsets or cranks in your basement!
     
  11. Werehatrack

    Werehatrack Guest

    On 26 Jan 2006 07:45:06 -0800, "Scott Gordo" <[email protected]>
    wrote:

    >
    >Llatikcuf wrote:
    >> Talked to the people at Thomson today about their stems, he said they
    >> were machined from a solid extruded block and related the idea of clay
    >> being pushed through a small opening. How does extruding a solid block
    >> of aluminum compare in strength and fatigue resistance to the item
    >> being forged?
    >>

    >
    >That's interesting. I'd figured that it was forged and then milled
    >down. Doesn't that seem like the ideal solution?


    Ideal, but far more costly. Many designs and dimensions of finished
    product can be produced from identical extruded stock by merely
    setting up a CNC lathe and milling machines to peel them out. With
    forging, each major revision or significant dimensional variant would
    require a new set of dies if the process were going to produce a real
    benefit. In general, the closer the forged blank can be to a finished
    product, the better the end result.
    --
    Typoes are a feature, not a bug.
    Some gardening required to reply via email.
    Words processed in a facility that contains nuts.
     
  12. In article <[email protected]>,
    [email protected] says...

    >Indeed, yet one is left to wonder why Thomson decided to do it this
    >way. Do they believe it's stronger than it's forged competitor?


    It doesn't need to be stronger than a competitors stem. It only needs to be
    strong enough for the task at hand.
    ------------
    Alex
     
  13. Dave

    Dave Guest

    I don't believe that Chris King uses the term CNC in their advertising.
    Certainly not on their website. Can you point me somewhere else?

    Why are cup and cone bearings better than cartridge?

    In my experience, my Chris King hubs have outperformed my Shimano
    hubs by a wide margin.
     
  14. M-gineering

    M-gineering Guest

    Dave wrote:
    > I don't believe that Chris King uses the term CNC in their advertising.
    > Certainly not on their website. Can you point me somewhere else?
    >

    P3 of the catalogue I have starts with an impressive array of cnc
    machinery, and of course there are the CNC hubshakers

    > Why are cup and cone bearings better than cartridge?


    Bigger balls for a given space, more tolerant for misalignment, less
    inclined to fail catastrophically


    > In my experience, my Chris King hubs have outperformed my Shimano
    > hubs by a wide margin.


    They bloody well should for that kind of money!

    --
    ---
    Marten Gerritsen

    INFOapestaartjeM-GINEERINGpuntNL
    www.m-gineering.nl
     
  15. Tim McNamara

    Tim McNamara Guest

    "Dave" <[email protected]> writes:

    > I don't believe that Chris King uses the term CNC in their
    > advertising. Certainly not on their website. Can you point me
    > somewhere else?
    >
    > Why are cup and cone bearings better than cartridge?


    Adjustable bearing preload, for one thing. There are cartridge
    bearings that offer this- examples are seen in Maxi-CAR hubs from
    France. There are people using the same bearings in those hubs for
    decades, smooth as silk still. I have a Mavic 501 front hub which
    also seems to had adjustable preload cartridge bearings and is the
    smoothest hub I own. I've never had cause to take it apart.

    > In my experience, my Chris King hubs have outperformed my Shimano
    > hubs by a wide margin.


    In terms of durability? I've never used Kings, but my Phil Wood hubs
    have all provided excellent service. The newer FSA designs permit
    bearing replacement in a couple of minutes
     
  16. Dave who? writes:

    > I don't believe that Chris King uses the term CNC in their advertising.
    > Certainly not on their website. Can you point me somewhere else?


    > Why are cup and cone bearings better than cartridge?


    Radial cartridge bearings are made for radial loads requiring a small
    axial load to prevent balldrop, the gap between balls when there is
    radial clearance, the clearance that is naturally there in such
    bearings. Axial preload plays havoc with these bearings especially
    when a QR is closed enough to exceed the load raring of the cartridge
    bearing.

    > In my experience, my Chris King hubs have outperformed my Shimano
    > hubs by a wide margin.


    That depends on whether you are hard on QR closures or not. Shimano
    angular contact cartridge head bearings are excellent. I don't
    understand why Shimano doesn't also make similar snap-together angular
    contact wheel bearings.

    Jobst Brandt
     
  17. Sorni

    Sorni Guest

    M-gineering wrote:

    > Bigger balls for a given space


    Family newsgroup, buddy.

    Bill "one for the Squidster" S.
     
  18. Llatikcuf

    Llatikcuf Guest

    Sorni wrote:
    > M-gineering wrote:
    >
    > > Bigger balls for a given space

    >
    > Family newsgroup, buddy.


    Who said this was a family oriented newsgroup? Half of the time were
    talking about torqing nipples, how grease packed our balls should be,
    ball diameter...... Not to metion all the stuff we hear M. Wallace is
    doing. Sounds pretty NC-17 to me.

    -Nate
     
  19. Werehatrack

    Werehatrack Guest

    On 26 Jan 2006 14:01:39 -0800, "Dave" <[email protected]> wrote:

    >I don't believe that Chris King uses the term CNC in their advertising.
    >Certainly not on their website. Can you point me somewhere else?


    Thirty years ago, CNC milling was a relatively new, exotic and (yes,
    to marketing people) "sexy" feature. Today, it's the de facto
    standard for production of repeatable items. As such, there's no need
    to mention it, nor anything to be gained in doing so. Even cast and
    forged parts may be finished using a CNC lathe or mill; this neither
    improves the former dramatically nor detracts from the qualities of
    the latter. The fact that Chris King does not mention CNC processes
    explicitly is not significant.

    >Why are cup and cone bearings better than cartridge?


    Whther the manufacturer of the assembly is still in business when the
    item needs servicing or not, a cup-and-cone headset can be fitted with
    new balls and returned to service as long as the cups and cones are
    not damaged. If the cartridge bearing is NLA, either because the
    supplier has stopped supporting it or has gone out of business, the
    whole assembly is junk. No headset uses a generic cartridge bearing
    TTBOMK, though some hubs do.

    >In my experience, my Chris King hubs have outperformed my Shimano
    >hubs by a wide margin.


    In what way, and which models of each were you comparing? Factors
    that are vital to one rider may be irrelevant to another.
    --
    Typoes are a feature, not a bug.
    Some gardening required to reply via email.
    Words processed in a facility that contains nuts.
     
  20. Chalo

    Chalo Guest

    [email protected] wrote:
    >
    > Even more fun is that so few people know exactly what CNC refers to..
    > last I checked a CNC hobby mill or lathe from Sherline was under $2000.
    >
    > You can CNC machine your own hubs, headsets or cranks in your basement!


    Not on a Sherline, you can't. You could make some sweet bike bling for
    Barbie or Ken, maybe.

    But you can get in the CNC game with some decent job-shop type
    equipment that now retails for under $20,000. A Bridgeport-clone mill
    with 2-1/2 axis control is surprisingly capable for pieces in the
    bike-part size range.

    The 3 axis mill I run on a daily basis has a 35" x 35" x 80" work
    envelope and a 30 HP spindle motor. But one of those will set you back
    $250,000 at least, not counting a place to put it.

    Chalo Colina
     
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