Richard M Sachs <firstname.lastname@example.org> wrote:
>>>>i too believe, in essence, that the differences exist. i believe more strongly, however, that the differences exist but play less a part in the 'assembled' frame as compared with the raw material in its 'tested' form. my opinion is that the frame, in its finished state, is a different animal; you're not buying a pipe, you're buying a bunch of pipes formed into an incredibly strong and mature design: the diamond bicycle frame.
Yes too many conumers buy bikes (and many other things) based on spec's, and not even real specs like yield strength of metal (as tested), for what little that tells you, but on spec's like "853" which is "good tubes." The whole is greater than the sum, at least when you're talking about a good bike.
>>>>>as for the rest of this stuff, SORRY to appear cynical, but i do believe most of the 'engineering' choices made relative to a bicycle's frame materials are, in fact made to take into account the lowest common denominator: the industrial work force.
As in, "no we won't spec Tange Prestige on a $500 bike because we can't afford to pay people to properly braze it, rather than because we can't afford the tubes themselves."
>>>>how, the suits in charge have to make their choices palatable. the consumers are buying sex. they're buying an image of what_they_can_be if they ride the latest and greatest. and-honestly-the last part about market and profit related choices-i do not begrudge these suits, their choices, or someone's desire to profit. i am just trying to say that, in my opinion, the materials 'thing' is overated.
True. I just don't think that every new thing that comes along only comes along to promote some fictional improvement, even if some/many do. I have no doubt that you will agree.
On Thu, 30 May 2002 12:24:10 -0700 (PDT) Tom Dalton
> I'm not sure you took my comments in the spirit in which they were
> intended, or that I have fully understood the intent of your
> message. What I was suggesting is that while there may not be an
> appreciable difference between two otherwise identical bikes, one
> with tubes made from alloy A with heart treatment 1 and one with
> tubes of alloy B / heat treatment 2, these alloys and heat
> treatments are not just conjured up to pull the wool over the eyes
> of hapless retail bike buyers, or even hapless engineers at bike
> companies. Metallurgical differences are real, and exist to meet
> real demands brought about by a world of potential end uses, even if
> certain of the effects of these differences may be negligable in
> certain end uses.
> For example, the Reynolds 753 material was developed to meet the
> yield strength requirements of a super-thin-walled tubeset because
> the 531 material would not be adequately strong at the desired
> gauges. 753 had a real edge in yield strength that made it strong
> enough to meet the real demands of light gauge tubes, but the
> modulus of steel is fixed so the thin tubes don't really work
> because they are too flexy. By the time Reynolds drew the 753
> material into tubes that were thick enough not to noodle around
> under a strong rider, the added stregth imparted by the material was
> unnesessary... and in the end other differences (fatigue strength?)
> may even have contributed to increased failure rates.
> Tom Dalton Bethlehem, PA
> Richard M Sachs wrote: Tom Dalton writes:
> <...This assumes that consumers, including engineers spec'ing
> steels for bike tubes, turbine blades, surgical instruments, etc.
> are universally idiotic...> (continued in the text below)
> uh, i think we have a winner!
> at the risk of losing friends on the list by agreeing 100% with
> this here statement, i'll only say that (as far as materials go...)
> there is a 'this year's flavor' with regards to material, joining
> processes, shapes, guages, etcetera. (nearly) all the stuff
> presented to the consumer base as a choice worthy of
> consideration is made for industrial use, read: production
> bicycle making. bread and butter bikes. price point bikes.
> 'i just went to the mall and bought this here bike' bikes.
> and guys-don't bust me up on this. it's only my opinion!
> you don't have to believe it to the degree that i do.
> chester, ct
> On Thu, 30 May 2002 10:21:04 -0700 (PDT) Tom Dalton
> > The Bohemian Bicycles website contains Scot Nichol's 6-part series
> > about frame materials. It is somewhat general, but quite
> > informative. It don't know a lot about materials science, but I
> > take one undergraduate course and Nichol's information was
> > consistent with what I learned in that class. I think what Steven
> > is driving at is that the mechanical properties of a steel tube
> > would influence ride (not durability, not yield strength) depend
> > primarily on the geometry of the tube (wall thickness, diameter,
> > subtler aspects of material distribution dictated by tapers and
> > butting). The density of steels is essentially constant as is the
> > elastic modulus, therefore "stiffness" and weight should not
> > with different alloys, assuming the tubes are dimensionally
> > identical. The catch is that a carbon steel bike would be pretty
> > frail if the tubes were thin-walled and oversized. It would be
> > light and stiff, but a collision with a pothole may exceed it's
> > yield strength.
> > The above is consistent with what they teach you in school, in the
> > real world of frame building things may be different, at least in
> > subtle ways. Personally I've never ridden two frames of differing
> > materials that were otherwise similar enough to provide adequate
> > control to assess the "feel" of different alloys and heat
> > treatments... but based on what I've read, I doubt I'd feel a
> > difference. Of course alloys still matter for other reasons,
> > otherwise they wouldn't exist. Taken to the exteme, suggesting
> > otherwise implies that steel companies "invent" special, expensive
> > materials to screw consumers, when plain carbon steel would serve
> > all purposes adequately. This assumes that consumers, including
> > engineers spec'ing steels for bike tubes, turbine blades, surgical
> > instruments, etc. are universally idiotic. Hey, I'm no lover of
> > engineers, but I'll conceed that this is not the case.
> > Tom Dalton, with apologies to engineers, in Bethlehem, PA
> > NortonMarg@aol.com wrote: In a message dated 5/30/02 7:07:19 AM
> > Pacific Daylight Time,
> > email@example.com writes:
> > << I'm sure most people will chime in that I'm just full of it.
> > Before
> > you react look for the article in Bicycle Guide and look at the
> > materials used in bike construction 40 years ago. Also note that
> > we're talking about ride and not weight, longevity, ETC. . . Like
> > everyone I want to believe that it really does matter since I'm
> > paying extra for quality tubing, but when it comes to ride it just
> > doesn't matter. I'm now off to put on my asbestos underwear. >>
> > Have to disagree. Magazines publish articles to fill space and
> > magazines. I've said this before and I'll say it again, Albert
> > Eisentraut was
> > one of the first American builders to vary the tubing gauges in a
> > frame, not
> > just using the standard "tube set". It made a HUGE difference in
> > ride quality
> > and a minuscule difference in weight. If what you are saying is
> > you can
> > get a similar ride quality from cheap tubing (with a weight
> > penalty), that's
> > a somewhat fair statement. However, the cheaper, heavier steel
> > tubing doesn't
> > allow the artistic and talented frame builder to design in the
> > subtleties
> > that varying the best quality of tubes allows. Your statement
> > be fully
> > true if subtlety did not exist in the universe.
> > The smartest article I remember reading on the subject had to do
> > with telling
> > riders it's not the "steel" that matters, it's the "tubing". Tube
> > configuration, wall thickness, taper, etc. matters more to a
> > finished frame
> > than "what steel is it?"
> > Caeterus paribas, assuming first class workmanship.
> > Stevan Thomas
> > Alameda, CA