Yet another broken spoke



jim beam wrote:
> Peter Cole wrote:
>> jim beam wrote:
>>
>>> quantifiably, right? you have numbers?
>>
>>> that's not what i'm saying at all. what i /am/ saying is that if a
>>> spoke is interleaved, if it goes slack, the tension from its partner
>>> will cause considerably more bending excursion than if it had not
>>> been interleaved.
>>
>> You have numbers?
>>
>> My numbers say that 2mm spokes crossed 2cm from the ends will produce
>> a maximum skin stress from bending of about 30MPa. Of course the slack
>> spoke won't bend that much during the wheel cycle, in fact it will
>> bend hardly at all, since, because it is slack, there is no longer
>> much if any force at the crossing.
>
> again, i'm /NOT/ talking about the bend at the crossing - spokes don't
> break there. i'm talking about the effect the interleaving has on the
> /elbow/. it causes considerable deviation from the straight line, and
> this /has/ to be accommodated by an increased bending moment at the elbow.
>
> http://www.flickr.com/photos/38636024@N00/1313347532/

You misunderstand. I *am* describing the change on skin stress *at the
elbow* caused by the deflection of a spoke at the crossing. Worst case
(both spokes fully tensioned), it's small; in your scenario, it's much
smaller yet -- in other words, miniscule -- it can't possibly contribute
to fatigue.
 
jim beam wrote:
> Peter Cole wrote:
>> jim beam wrote:
>>> Peter Cole wrote:

>>>>>> Everybody knows this stuff. Lots of us have had nicked spokes
>>>>>> break in mid-span. So what? Stress + flaw = failure. Film at 11.
>>>>>
>>>>> eh? surface nicks are /not/ inclusions!!!
>>>>
>>>> Both are defects (obviously).
>>>
>>> wriggle, squirm. a nick is not an inclusion. period.
>>
>> No kidding, but they're both defects, flaws, stress concentrators --
>> take your pick -- or perhaps you'd like to explain why an "inclusion"
>> is a special form of defect from a fatigue POV?
>
> sure - if surface defects are controlled and kept below a certain
> feature size, fatigue can be substantially mitigated.

"Surface defects" -- of course those would include nicks.


> but in searching for an explanation of why even mirror polished
> materials still initiate fatigue at the surface, it was found that
> fatigue was initiating at inclusions where they interrupted the surface.
> removing the inclusions removed these initiators and fatigue life was
> found to be improved again.

Of course -- inclusions are defects. So are persistent slip bands.

<http://www.key-to-steel.com/Articles/Art162.htm>

"An overpowering structural consideration in fatigue is the fact that
fatigue cracks usually are initiated at a free surface. In those rare
instances where fatigue cracks initiate in the interior there is always
an interface involved, such as the interface of a carburized surface
layer and the base metal."

"An important structural feature, which appears to be unique to fatigue
deformation, is the formation on the surface of ridges and grooves
called slip-band extrusions and slip-band intrusions. Extremely careful
metallography on tapered sections through the surface of the specimen
has shown that fatigue cracks initiate at intrusions and extrusions."
 
jim beam wrote:
> Peter Cole wrote:
>> jim beam wrote:
>>> Peter Cole wrote:

>>>>>> Vacuum degassing was big news in the 50's. It's a cheap bulk
>>>>>> process, common as dirt. What else have you got?
>>>>>
>>>>> it's /cheaper/ than it was, but it's still expensive.
>>>>
>>>> No, it's not.
>>>
>>> er, it is actually.
>>>
>>>
>>>>
>>>>> and it didn't
>>>>> start being used for bike spoke material until the 70's
>>>>
>>>> Cite, please. It was used in auto sheet metal by that time.
>>>
>>> not even in the 80's big guy. that's the last time i went through a
>>> strip mill and it was either open ingot or con-cast. look at this stuff
>>> under a microscope some time and you'll see the evidence for yourself.
>>
>> Used by the Japanese for auto bodies in the 70's. US by 80's, little
>> man. How can this be "expensive" if it's used in massive quantities in
>> cars?
>
> but wasn't! not for bulk sheet. maybe you're thinking of oxygen lancing?
>
> http://en.wikipedia.org/wiki/Basic_oxygen_steelmaking

No. From that article (did you read it?):

"The first basic oxygen steelmaking process was the LD process developed
in 1952 by voestalpine AG in Linz, Austria. Some major steelmaking
companies in the US did not convert to this process for decades, with
the last Bessemer converter still operating commercially until 1968.

The LD process replaced both the previously common Siemens-Martin
process, also known as the open-hearth process, and the Bessemer process."

As you should know, vacuum degassing is not related to the "LD" process
which is merely an upgrade to the original Bessemer process, using
oxygen instead of air.

As for vacuum degassing (your magic process)
<http://www.memagazine.org/backissues/membersonly/april98/features/vacuum/vacuum.html>

"Vacuum-degassing systems, which are all customized, fall into two
categories. The first type, RH recirculating degassers invented by
Heraeus-Rheinstahl in Germany, involves inserting two legs, or snorkels,
of a vacuum chamber into a ladle of liquid steel. The metal is drawn
into the chamber via one snorkel that injects argon to promote
turbulence; it is then exposed to the vacuum to remove gases and
recirculated back through the other snorkel. The other system, a tank
degasser, is a vessel into which the ladle is sent and stirred by the
injection of argon. The chamber is depressurized to remove gases, and
finally the ladle is removed."

As for the timeline:

"Cramb noted that automakers' demand for ultralow-carbon sheet steel to
make lightweight but durable car panels for more-fuel-efficient cars has
been the major factor driving vacuum degassing's growing share of the
sheet-steel market in the later 1980s and early 1990s.

"One plant has been making over 1.2 million tons of degassed sheet steel
to supply the automotive market" out of an annual production of 6
million tons, according to Ron Holmes, a metallurgical engineer and
senior process consultant at Kvaerner Metals, a subsidiary of Kvaerner
ASA in Oslo, Norway. Kvaerner Metals has designed and installed numerous
vacuum-degassing systems for processing sheet steel for automotive end
users.

"Although this is a relatively new story in the United States, dating
from the late 1980s, Japanese steel makers were degassing sheet metal
for autos at least 10 years earlier,""
 
On Sun, 02 Sep 2007 12:24:38 -0400, Just A User
<[email protected]> wrote:

>It happened again! I broke ANOTHER spoke on my road bike. This makes the
>second break in a month maybe a month and a half. Now I know I don't
>have the lightest riding style compared to some riders. And I am not the
>lightest of all riders. But then again I am riding on 32 triple cross
>wheels. What I don't understand is why am I breaking them on the front
>wheel only? I thought the back wheel carried more weight. So I have a
>few extra spokes I bought when I had the wheel at the lbs for the last
>spoke replacement. But now I am thinking that a new / better machine
>built wheel, or cough, a handbuilt wheels might be a more reliable way
>to go. When I say handbuilt, I mean with my hands, that have no
>experience building wheels. All opinions welcome.
>
>J.A.U.


Boy, this thread is really getting carried away. Anyhow, I was
breaking spokes pretty regularly on my fairly cheapo Trek 7100 (low
end hybrid). I tried tension relief by squeezing the spokes a bit.
Maybe not the right way to do it, but since I know squat about wheels,
that was how I interpreted various advice.

Mine were breaking on the rear wheel. So I called Nashbar or
Performance (I forget which) and spoke to the guy about my
bike/wheel, and I ordered a wheel for around $100 that came with
double or triple butted spokes (they thicken near the rim and axle.
That was maybe a year ago and I haven't broken a spoke since.

I still try to stress relieve them once in a while, but I sure am
happy not to be breaking spokes.
 
On Mon, 10 Sep 2007 22:59:09 -0600, [email protected] wrote:


>>
>>Looks like steel hub flanges to me. Probably with low tension and a
>>heavy rim. The spokes are occasionally snug against the flange but
>>being less than what we'd call tensioned aren't 'seated' in a hub as
>>most wheels ridden by r.b.t. readers. Steel hubs are simply pierced and
>>often have no concession to a radiused edge. The spokes show marks from
>>both sides of the flange.
>
>Dear Andrew, Jobst, & Clare,
>
>These diagrams from the 3rd edition of "The Bicycle Wheel" may show
>the cause of the gouging:
>
>http://i16.tinypic.com/542bp10.jpg
>
>Under tension, the spoke cants in the thin, sharp-edged steel flange
>described by Jobst and Andrew.
>
>Cheers,
>
>Carl Fogel
Sturmey archer hub.

--
Posted via a free Usenet account from http://www.teranews.com
 
dgk wrote:

>
> Boy, this thread is really getting carried away. Anyhow, I was
> breaking spokes pretty regularly on my fairly cheapo Trek 7100 (low
> end hybrid). I tried tension relief by squeezing the spokes a bit.
> Maybe not the right way to do it, but since I know squat about wheels,
> that was how I interpreted various advice.

Good online writeup at Sheldon Brown's site.

>
> Mine were breaking on the rear wheel. So I called Nashbar or
> Performance (I forget which) and spoke to the guy about my
> bike/wheel, and I ordered a wheel for around $100 that came with
> double or triple butted spokes (they thicken near the rim and axle.
> That was maybe a year ago and I haven't broken a spoke since.
>
> I still try to stress relieve them once in a while, but I sure am
> happy not to be breaking spokes.

You only have to do it once.
 
Peter Cole wrote:
> jim beam wrote:
>> Peter Cole wrote:
>>> jim beam wrote:
>>>> Peter Cole wrote:
>
>>>>>>> Vacuum degassing was big news in the 50's. It's a cheap bulk
>>>>>>> process, common as dirt. What else have you got?
>>>>>>
>>>>>> it's /cheaper/ than it was, but it's still expensive.
>>>>>
>>>>> No, it's not.
>>>>
>>>> er, it is actually.
>>>>
>>>>
>>>>>
>>>>>> and it didn't
>>>>>> start being used for bike spoke material until the 70's
>>>>>
>>>>> Cite, please. It was used in auto sheet metal by that time.
>>>>
>>>> not even in the 80's big guy. that's the last time i went through a
>>>> strip mill and it was either open ingot or con-cast. look at this
>>>> stuff
>>>> under a microscope some time and you'll see the evidence for yourself.
>>>
>>> Used by the Japanese for auto bodies in the 70's. US by 80's, little
>>> man. How can this be "expensive" if it's used in massive quantities
>>> in cars?
>>
>> but wasn't! not for bulk sheet. maybe you're thinking of oxygen
>> lancing?
>>
>> http://en.wikipedia.org/wiki/Basic_oxygen_steelmaking
>
> No. From that article (did you read it?):
>
> "The first basic oxygen steelmaking process was the LD process developed
> in 1952 by voestalpine AG in Linz, Austria. Some major steelmaking
> companies in the US did not convert to this process for decades, with
> the last Bessemer converter still operating commercially until 1968.
>
> The LD process replaced both the previously common Siemens-Martin
> process, also known as the open-hearth process, and the Bessemer process."
>
> As you should know, vacuum degassing is not related to the "LD" process
> which is merely an upgrade to the original Bessemer process, using
> oxygen instead of air.

not only did i read it, i've done it. and it's the process that
produces the majority of the material used in bulk product like sheet,
rod, bar, etc. used today. the product is good enough that you don't
need to worry too much about additional refining unless you have a
special use.


>
> As for vacuum degassing (your magic process)
> <http://www.memagazine.org/backissues/membersonly/april98/features/vacuum/vacuum.html>
>
>
> "Vacuum-degassing systems, which are all customized, fall into two
> categories. The first type, RH recirculating degassers invented by
> Heraeus-Rheinstahl in Germany, involves inserting two legs, or snorkels,
> of a vacuum chamber into a ladle of liquid steel. The metal is drawn
> into the chamber via one snorkel that injects argon to promote
> turbulence; it is then exposed to the vacuum to remove gases and
> recirculated back through the other snorkel. The other system, a tank
> degasser, is a vessel into which the ladle is sent and stirred by the
> injection of argon. The chamber is depressurized to remove gases, and
> finally the ladle is removed."
>
> As for the timeline:
>
> "Cramb noted that automakers' demand for ultralow-carbon sheet steel to
> make lightweight but durable car panels for more-fuel-efficient cars has
> been the major factor driving vacuum degassing's growing share of the
> sheet-steel market in the later 1980s and early 1990s.
>
> "One plant has been making over 1.2 million tons of degassed sheet steel
> to supply the automotive market" out of an annual production of 6
> million tons, according to Ron Holmes, a metallurgical engineer and
> senior process consultant at Kvaerner Metals, a subsidiary of Kvaerner
> ASA in Oslo, Norway. Kvaerner Metals has designed and installed numerous
> vacuum-degassing systems for processing sheet steel for automotive end
> users.
>
> "Although this is a relatively new story in the United States, dating
> from the late 1980s, Japanese steel makers were degassing sheet metal
> for autos at least 10 years earlier,""


ok, first, 10 points for producing an interesting article for once.

second, if you read further, you'll see that it gets slightly more
specific about the product this material is used to produce. this may
indeed be used in some sheet used in vehicles, but price alone prohibits
it being used for the majority - it would only make sense for some
chassis componentry and other fatigued components like suspension and
engine bolts. and even then, not every manufacturer would be
interested. it would be great for forged cranks for example, but the
majority of producers cast cranks because it's so much cheaper - fatigue
benefits of superior materials be hanged.

as for chronology, the benefits have been known for a long time - since
the 30's i believe, but knowing about it, being able to produce it, and
/paying/ for it are all completely different things. i don't believe
that an auto industry that will save 6' of copper wire by using the same
bulb for brake lights and turn signals, or not using washers/gaskets on
spark plugs, has the /slightest/ interest in paying extra for vacuum
degassed steels when cheap cast iron **** will do.
 
On 2007-09-12, jim beam <[email protected]> wrote:
> Peter Cole wrote:
[...]
>> As for vacuum degassing (your magic process)
>> <http://www.memagazine.org/backissues/membersonly/april98/features/vacuum/vacuum.html>
[...]
> ok, first, 10 points for producing an interesting article for once.
>
> second, if you read further, you'll see that it gets slightly more
> specific about the product this material is used to produce. this may
> indeed be used in some sheet used in vehicles, but price alone prohibits
> it being used for the majority - it would only make sense for some
> chassis componentry and other fatigued components like suspension and
> engine bolts.

I thought it said the degassing for cars was not to remove hydrogen for
better cold-worked stuff but a slightly different process, although
based on the same principle, to remove carbon, making this "ultra-low
carbon" stuff for body panels.

I thought the point of that was it was then easier to make into
pressings. But I would have thought it would be rather soft. Perhaps
that doesn't matter though, and perhaps it's the reason why you can ping
car body panels in and out quite easily these days when in the past it
required repeated applications of a lump hammer.

[...]
> as for chronology, the benefits have been known for a long time - since
> the 30's i believe, but knowing about it, being able to produce it, and
> /paying/ for it are all completely different things. i don't believe
> that an auto industry that will save 6' of copper wire by using the same
> bulb for brake lights and turn signals, or not using washers/gaskets on
> spark plugs, has the /slightest/ interest in paying extra for vacuum
> degassed steels when cheap cast iron **** will do.

You add up the cost though. The degassing process might cost a bit but
maybe you can use a bit less steel that way and also produce a lighter
and more fuel-efficient (and therefore competitive-- at least outside
the USA) car.
 
On Sep 7, 9:13 pm, [email protected] wrote:
> Michael Press writes:
> >>> The spokes lose huge amounts of pre-tension as they roll under the
> >>> wheel. The individual the spokes all the way around the wheel show
> >>> an increase of only up to 10% in tension, compared to the spoke
> >>> directly under the axle's loss of tension.
> >> Right. Under what criteria is a 10% increase in tension
> >> insignificant, as it was described by Brandt? And in your testing,
> >> as well as everyone else's, the greatest loss of tension was in the
> >> spokes perpendicular to the spokes that lost tension.
> >> The loss of tension caused by the local flexing of the rim cannot
> >> be balanced by a rise in tension by the rest of the spokes; OTOH,
> >> the flexing of the rim caused by the ovalization of the hoop _must_
> >> be offset by a rise in tension by the rest of the spokes.
> > The hoop does not "ovalize" in normal use, the use for which it is
> > intended; to wit: transmitting a compressive load between the
> > contact patch and the axle. The shape of the distortion of a rim
> > under load is lumpy.
> > On a thirty six spoke wheel the greatest change in spoke length is
> > at the contact patch where it is -0.153 mm. The next local maximum
> > of absolute spoke length change is four spokes from the contact
> > patch, or one ninth of the circumference where the change is 0.014
> > mm. After that all the spokes are extended by 0.007 mm. The rim
> > remains circular, except for an indentation at the contact patch and
> > a couple lumps adjacent to the contact patch.
>
> To put it a different way, the rim is flattened at the road contact
> area and this flattening increases the radius of the remaining
> circular part of the rim (the previous arc having a shorter linear
> length than when flattened. Of course you can read about this in "the
> Bicycle Wheel" which is what inspired Ian and Henry Gavin to publish
> the same material in their own fora.
>
> http://www.avocet.com/wheelbook/wheelbook.html
>
> >> The latter effect is where the wheel gets its strength; it is
> >> ridiculous to suggest that the rise in tension of the other spokes
> >> is insignificant because without that rise in tension you might as
> >> well be riding a wheel with all the spokes detensioned to the point
> >> that all the wheel strength derives completely from the strength of
> >> the rim alone. To say that the rise in tension of the other spokes
> >> is insignificant is just utterly ridiculous.
>
> If you research the many times this subject has appeared in this
> forum, you'll find that the vertical component of tension increases,
> caused by spreading the wheel circumference, sum to zero, leaving only
> the reduction in downward force of the spokes in the "load affected
> zone" as the sole support of axle loads. The reason this is so, is
> that at either end of the load affected zone, a bulge caused by rim
> stiffness in the transition from the flattened area to the circular
> part does not allow a sudden transition. This may slightly differ
> depending on the bending stiffness of the rim cross section used as a
> model. The ones in the book are MA-2's.
>
> Jobst Brandt- Hide quoted text -
>
> - Show quoted text -

Does this sentance make more sence?

"In the situation of a wheel with spokes of even tension being
statically loaded, spokes under the the horizontal centerline of the
hub come under relatively less tension than those on or above the
centerline of the hub, with the spokes experiencing the greatest
amount of change being those closest to the vertical plane, with a
load spread relative to rim stiffness number of spokes, and spoke
type"
 
Ben C wrote:
> On 2007-09-12, jim beam <[email protected]> wrote:
>> Peter Cole wrote:
> [...]
>>> As for vacuum degassing (your magic process)
>>> <http://www.memagazine.org/backissues/membersonly/april98/features/vacuum/vacuum.html>
> [...]
>> ok, first, 10 points for producing an interesting article for once.
>>
>> second, if you read further, you'll see that it gets slightly more
>> specific about the product this material is used to produce. this may
>> indeed be used in some sheet used in vehicles, but price alone prohibits
>> it being used for the majority - it would only make sense for some
>> chassis componentry and other fatigued components like suspension and
>> engine bolts.
>
> I thought it said the degassing for cars was not to remove hydrogen for
> better cold-worked stuff but a slightly different process, although
> based on the same principle, to remove carbon, making this "ultra-low
> carbon" stuff for body panels.

good point - and oxygen lancing is the process that removes the carbon.


>
> I thought the point of that was it was then easier to make into
> pressings. But I would have thought it would be rather soft. Perhaps
> that doesn't matter though, and perhaps it's the reason why you can ping
> car body panels in and out quite easily these days when in the past it
> required repeated applications of a lump hammer.

softer is definitely more formable, but body panel sheet is cold worked
and thus not fully soft like it would be if it were annealed.


>
> [...]
>> as for chronology, the benefits have been known for a long time - since
>> the 30's i believe, but knowing about it, being able to produce it, and
>> /paying/ for it are all completely different things. i don't believe
>> that an auto industry that will save 6' of copper wire by using the same
>> bulb for brake lights and turn signals, or not using washers/gaskets on
>> spark plugs, has the /slightest/ interest in paying extra for vacuum
>> degassed steels when cheap cast iron **** will do.
>
> You add up the cost though. The degassing process might cost a bit but
> maybe you can use a bit less steel that way and also produce a lighter
> and more fuel-efficient (and therefore competitive-- at least outside
> the USA) car.

you're right, but i don't think domestic producers have the slightest
interest in fuel efficiency. and all the so-called "safety" features
built into cars today add to the weight of vehicles significantly.
weight is directly contradictory to fuel efficiency. and making sure a
car can withstand a 30mph side impact with a semi is somewhat pointless
given that the occupants still impact the interior of the vehicle with
pretty much zero deceleration room whether the shell deforms or not.

regarding cost of materials, yes, there comes a point where reducing
material pays back, but for cast iron cranks, the cost savings are not
just material, but processing. and that is substantial.
 
jim beam wrote:
> Peter Cole wrote:
>> jim beam wrote:
>>> Peter Cole wrote:
>>>> jim beam wrote:
>>>>> Peter Cole wrote:
>>
>>>>>>>> Vacuum degassing was big news in the 50's. It's a cheap bulk
>>>>>>>> process, common as dirt. What else have you got?
>>>>>>>
>>>>>>> it's /cheaper/ than it was, but it's still expensive.
>>>>>>
>>>>>> No, it's not.
>>>>>
>>>>> er, it is actually.
>>>>>
>>>>>
>>>>>>
>>>>>>> and it didn't
>>>>>>> start being used for bike spoke material until the 70's
>>>>>>
>>>>>> Cite, please. It was used in auto sheet metal by that time.
>>>>>
>>>>> not even in the 80's big guy. that's the last time i went through a
>>>>> strip mill and it was either open ingot or con-cast. look at this
>>>>> stuff
>>>>> under a microscope some time and you'll see the evidence for yourself.
>>>>
>>>> Used by the Japanese for auto bodies in the 70's. US by 80's, little
>>>> man. How can this be "expensive" if it's used in massive quantities
>>>> in cars?
>>>
>>> but wasn't! not for bulk sheet. maybe you're thinking of oxygen
>>> lancing?
>>>
>>> http://en.wikipedia.org/wiki/Basic_oxygen_steelmaking
>>
>> No. From that article (did you read it?):
>>
>> "The first basic oxygen steelmaking process was the LD process
>> developed in 1952 by voestalpine AG in Linz, Austria. Some major
>> steelmaking companies in the US did not convert to this process for
>> decades, with the last Bessemer converter still operating commercially
>> until 1968.
>>
>> The LD process replaced both the previously common Siemens-Martin
>> process, also known as the open-hearth process, and the Bessemer
>> process."
>>
>> As you should know, vacuum degassing is not related to the "LD"
>> process which is merely an upgrade to the original Bessemer process,
>> using oxygen instead of air.
>
> not only did i read it, i've done it. and it's the process that
> produces the majority of the material used in bulk product like sheet,
> rod, bar, etc. used today. the product is good enough that you don't
> need to worry too much about additional refining unless you have a
> special use.

OK, so it has nothing to do with "vacuum degassing"?


>
>
>>
>> As for vacuum degassing (your magic process)
>> <http://www.memagazine.org/backissues/membersonly/april98/features/vacuum/vacuum.html>
>>
>>
>> "Vacuum-degassing systems, which are all customized, fall into two
>> categories. The first type, RH recirculating degassers invented by
>> Heraeus-Rheinstahl in Germany, involves inserting two legs, or
>> snorkels, of a vacuum chamber into a ladle of liquid steel. The metal
>> is drawn into the chamber via one snorkel that injects argon to
>> promote turbulence; it is then exposed to the vacuum to remove gases
>> and recirculated back through the other snorkel. The other system, a
>> tank degasser, is a vessel into which the ladle is sent and stirred by
>> the injection of argon. The chamber is depressurized to remove gases,
>> and finally the ladle is removed."
>>
>> As for the timeline:
>>
>> "Cramb noted that automakers' demand for ultralow-carbon sheet steel
>> to make lightweight but durable car panels for more-fuel-efficient
>> cars has been the major factor driving vacuum degassing's growing
>> share of the sheet-steel market in the later 1980s and early 1990s.
>>
>> "One plant has been making over 1.2 million tons of degassed sheet
>> steel to supply the automotive market" out of an annual production of
>> 6 million tons, according to Ron Holmes, a metallurgical engineer and
>> senior process consultant at Kvaerner Metals, a subsidiary of Kvaerner
>> ASA in Oslo, Norway. Kvaerner Metals has designed and installed
>> numerous vacuum-degassing systems for processing sheet steel for
>> automotive end users.
>>
>> "Although this is a relatively new story in the United States, dating
>> from the late 1980s, Japanese steel makers were degassing sheet metal
>> for autos at least 10 years earlier,""
>
>
> ok, first, 10 points for producing an interesting article for once.

Why don't you just stick to the point?

>
> second, if you read further, you'll see that it gets slightly more
> specific about the product this material is used to produce.

Funny, I don't see that.

> this may
> indeed be used in some sheet used in vehicles, but price alone prohibits
> it being used for the majority - it would only make sense for some
> chassis componentry and other fatigued components like suspension and
> engine bolts.


>> "One plant has been making over 1.2 million tons of degassed sheet
>> steel to supply the automotive market" (annual).

Given that the US annual vehicle production is around 15M, just that one
plant would be contributing around 200lb of *sheet* to the average vehicle.


> and even then, not every manufacturer would be
> interested. it would be great for forged cranks for example, but the
> majority of producers cast cranks because it's so much cheaper - fatigue
> benefits of superior materials be hanged.

http://tinyurl.com/ywqhhy


> as for chronology, the benefits have been known for a long time - since
> the 30's i believe, but knowing about it, being able to produce it, and
> /paying/ for it are all completely different things. i don't believe
> that an auto industry that will save 6' of copper wire by using the same
> bulb for brake lights and turn signals, or not using washers/gaskets on
> spark plugs, has the /slightest/ interest in paying extra for vacuum
> degassed steels when cheap cast iron **** will do.

Well, you're entitled to your beliefs, but it seems you are wrong.

As for vacuum degassing being somehow cost prohibitive for bicycle
spokes, consider that even at an extra $100/ton, the change in raw
material costs would be less than a dime for a bike's worth of spokes.
 
jim beam wrote:

[vacuum degassed steel]

> as for chronology, the benefits have been known for a long time - since
> the 30's i believe, but knowing about it, being able to produce it, and
> /paying/ for it are all completely different things. i don't believe
> that an auto industry that will save 6' of copper wire by using the same
> bulb for brake lights and turn signals, or not using washers/gaskets on
> spark plugs, has the /slightest/ interest in paying extra for vacuum
> degassed steels when cheap cast iron **** will do.

An interesting report from *1966*:
<http://stinet.dtic.mil/oai/oai?&verb=getRecord&metadataPrefix=html&identifier=AD0803703>

"VACUUM-DEGASSED STEELS FROM THE CONSUMER'S VIEWPOINT

Numerous industrial users were asked for their appraisal of
vacuum-degassed steel. Their responses regarding the merits of this
vacuum treatment were varied. ...

Unfortunately, many of the users could not give a meaningful evaluation
because they knew that frequently their suppliers filled orders with
vacuum-degassed steels even though such treatment was not specified."

Sounds like cost wasn't a deal breaker even in 1966.
 
On Sep 12, 5:46 pm, Ted Bennett <[email protected]> wrote:
> [email protected] wrote:
> > Does this sentance make more sence?
>
> No, that sentence does not make more sense.
>
> --
> Ted Bennett

My sentance strucutre is not great, and I can't quite find the right
words, but I feel Im pretty close.

I think Brant and others have made a mistake in pin pointing the lower
2 or 3 spokes as bearing the load on bicycle wheels. This is simply
not the case. It may be the case in some wheels, due to material
properties. Rim stiffness now plays a major role in how the load is
spread in a wheel. The subjective example that all this is based on is
just not good enough to come to a broad sweeping conclusion for all
spoked bicycle wheels.

Does that make any sence?
 
Hjulcompaniet? writes:

>>>>> The spokes lose huge amounts of pre-tension as they roll under
>>>>> the wheel. The individual the spokes all the way around the
>>>>> wheel show an increase of only up to 10% in tension, compared to
>>>>> the spoke directly under the axle's loss of tension.

>>>> Right. Under what criteria is a 10% increase in tension
>>>> insignificant, as it was described by Brandt? And in your
>>>> testing, as well as everyone else's, the greatest loss of tension
>>>> was in the spokes perpendicular to the spokes that lost tension.

>>>> The loss of tension caused by the local flexing of the rim cannot
>>>> be balanced by a rise in tension by the rest of the spokes; OTOH,
>>>> the flexing of the rim caused by the ovalization of the hoop
>>>> _must_ be offset by a rise in tension by the rest of the spokes.

>>> The hoop does not "ovalize" in normal use, the use for which it is
>>> intended; to wit: transmitting a compressive load between the
>>> contact patch and the axle. The shape of the distortion of a rim
>>> under load is lumpy.

>>> On a thirty six spoke wheel the greatest change in spoke length is
>>> at the contact patch where it is -0.153 mm. The next local
>>> maximum of absolute spoke length change is four spokes from the
>>> contact patch, or one ninth of the circumference where the change
>>> is 0.014 mm. After that all the spokes are extended by 0.007 mm.
>>> The rim remains circular, except for an indentation at the contact
>>> patch and a couple lumps adjacent to the contact patch.

>> To put it a different way, the rim is flattened at the road contact
>> area and this flattening increases the radius of the remaining
>> circular part of the rim (the previous arc having a shorter linear
>> length than when flattened. Of course you can read about this in
>> "the Bicycle Wheel" which is what inspired Ian and Henry Gavin to
>> publish the same material in their own fora.

http://www.avocet.com/wheelbook/wheelbook.html

>>>> The latter effect is where the wheel gets its strength; it is
>>>> ridiculous to suggest that the rise in tension of the other
>>>> spokes is insignificant because without that rise in tension you
>>>> might as well be riding a wheel with all the spokes detensioned
>>>> to the point that all the wheel strength derives completely from
>>>> the strength of the rim alone. To say that the rise in tension
>>>> of the other spokes is insignificant is just utterly ridiculous.

>> If you research the many times this subject has appeared in this
>> forum, you'll find that the vertical component of tension
>> increases, caused by spreading the wheel circumference, sum to
>> zero, leaving only the reduction in downward force of the spokes in
>> the "load affected zone" as the sole support of axle loads. The
>> reason this is so, is that at either end of the load affected zone,
>> a bulge caused by rim stiffness in the transition from the
>> flattened area to the circular part does not allow a sudden
>> transition. This may slightly differ depending on the bending
>> stiffness of the rim cross section used as a model. The ones in
>> the book are MA-2's.

> Does this sentance make more sence?

> "In the situation of a wheel with spokes of even tension being
> statically loaded, spokes under the the horizontal centerline of the
> hub come under relatively less tension than those on or above the
> centerline of the hub, with the spokes experiencing the greatest
> amount of change being those closest to the vertical plane, with a
> load spread relative to rim stiffness number of spokes, and spoke
> type"

If you read the above, you can deduce that the quote does not make
sense. If still in doubt, get a copy of the book and read more about
it.

Jobst Brandt
 
On Sep 12, 7:29 pm, [email protected] wrote:
> Hjulcompaniet? writes:
> >>>>> The spokes lose huge amounts of pre-tension as they roll under
> >>>>> the wheel. The individual the spokes all the way around the
> >>>>> wheel show an increase of only up to 10% in tension, compared to
> >>>>> the spoke directly under the axle's loss of tension.
> >>>> Right. Under what criteria is a 10% increase in tension
> >>>> insignificant, as it was described by Brandt? And in your
> >>>> testing, as well as everyone else's, the greatest loss of tension
> >>>> was in the spokes perpendicular to the spokes that lost tension.
> >>>> The loss of tension caused by the local flexing of the rim cannot
> >>>> be balanced by a rise in tension by the rest of the spokes; OTOH,
> >>>> the flexing of the rim caused by the ovalization of the hoop
> >>>> _must_ be offset by a rise in tension by the rest of the spokes.
> >>> The hoop does not "ovalize" in normal use, the use for which it is
> >>> intended; to wit: transmitting a compressive load between the
> >>> contact patch and the axle. The shape of the distortion of a rim
> >>> under load is lumpy.
> >>> On a thirty six spoke wheel the greatest change in spoke length is
> >>> at the contact patch where it is -0.153 mm. The next local
> >>> maximum of absolute spoke length change is four spokes from the
> >>> contact patch, or one ninth of the circumference where the change
> >>> is 0.014 mm. After that all the spokes are extended by 0.007 mm.
> >>> The rim remains circular, except for an indentation at the contact
> >>> patch and a couple lumps adjacent to the contact patch.
> >> To put it a different way, the rim is flattened at the road contact
> >> area and this flattening increases the radius of the remaining
> >> circular part of the rim (the previous arc having a shorter linear
> >> length than when flattened. Of course you can read about this in
> >> "the Bicycle Wheel" which is what inspired Ian and Henry Gavin to
> >> publish the same material in their own fora.
>
> http://www.avocet.com/wheelbook/wheelbook.html
>
>
>
>
>
> >>>> The latter effect is where the wheel gets its strength; it is
> >>>> ridiculous to suggest that the rise in tension of the other
> >>>> spokes is insignificant because without that rise in tension you
> >>>> might as well be riding a wheel with all the spokes detensioned
> >>>> to the point that all the wheel strength derives completely from
> >>>> the strength of the rim alone. To say that the rise in tension
> >>>> of the other spokes is insignificant is just utterly ridiculous.
> >> If you research the many times this subject has appeared in this
> >> forum, you'll find that the vertical component of tension
> >> increases, caused by spreading the wheel circumference, sum to
> >> zero, leaving only the reduction in downward force of the spokes in
> >> the "load affected zone" as the sole support of axle loads. The
> >> reason this is so, is that at either end of the load affected zone,
> >> a bulge caused by rim stiffness in the transition from the
> >> flattened area to the circular part does not allow a sudden
> >> transition. This may slightly differ depending on the bending
> >> stiffness of the rim cross section used as a model. The ones in
> >> the book are MA-2's.
> > Does this sentance make more sence?
> > "In the situation of a wheel with spokes of even tension being
> > statically loaded, spokes under the the horizontal centerline of the
> > hub come under relatively less tension than those on or above the
> > centerline of the hub, with the spokes experiencing the greatest
> > amount of change being those closest to the vertical plane, with a
> > load spread relative to rim stiffness number of spokes, and spoke
> > type"
>
> If you read the above, you can deduce that the quote does not make
> sense. If still in doubt, get a copy of the book and read more about
> it.
>
> Jobst Brandt- Hide quoted text -
>
> - Show quoted text -- Hide quoted text -
>
> - Show quoted text -

I think you've muddled together two posters there..
 
On Tue, 11 Sep 2007 10:00:19 -0400, Peter Cole
<[email protected]> wrote:

>dgk wrote:
>
>>
>> Boy, this thread is really getting carried away. Anyhow, I was
>> breaking spokes pretty regularly on my fairly cheapo Trek 7100 (low
>> end hybrid). I tried tension relief by squeezing the spokes a bit.
>> Maybe not the right way to do it, but since I know squat about wheels,
>> that was how I interpreted various advice.
>
>Good online writeup at Sheldon Brown's site.
>
>>
>> Mine were breaking on the rear wheel. So I called Nashbar or
>> Performance (I forget which) and spoke to the guy about my
>> bike/wheel, and I ordered a wheel for around $100 that came with
>> double or triple butted spokes (they thicken near the rim and axle.
>> That was maybe a year ago and I haven't broken a spoke since.
>>
>> I still try to stress relieve them once in a while, but I sure am
>> happy not to be breaking spokes.
>
>You only have to do it once.

It's really a drag. Usually the rear wheel, so I undo the brake so it
doesn't rub and just limp along slowly.

I was getting ready to buy one of those temporary spokes, but figured
that a better wheel was a better solution. I also got slime tubes. I
know that they weigh a bit more and increase rolling resistance, but
it isn't noticable - my bike already weighs a ton with all the lights
and batteries and pack on it. I haven't had a flat since I did that,
which is certainly several months. No flats, no broken spokes. Life
doesn't get much better.
 
Peter Cole wrote:
> jim beam wrote:
>
> [vacuum degassed steel]
>
>> as for chronology, the benefits have been known for a long time -
>> since the 30's i believe, but knowing about it, being able to produce
>> it, and /paying/ for it are all completely different things. i don't
>> believe that an auto industry that will save 6' of copper wire by
>> using the same bulb for brake lights and turn signals, or not using
>> washers/gaskets on spark plugs, has the /slightest/ interest in paying
>> extra for vacuum degassed steels when cheap cast iron **** will do.
>
> An interesting report from *1966*:
> <http://stinet.dtic.mil/oai/oai?&verb=getRecord&metadataPrefix=html&identifier=AD0803703>
>
>
> "VACUUM-DEGASSED STEELS FROM THE CONSUMER'S VIEWPOINT
>
> Numerous industrial users were asked for their appraisal of
> vacuum-degassed steel. Their responses regarding the merits of this
> vacuum treatment were varied. ...
>
> Unfortunately, many of the users could not give a meaningful evaluation
> because they knew that frequently their suppliers filled orders with
> vacuum-degassed steels even though such treatment was not specified."
>
> Sounds like cost wasn't a deal breaker even in 1966.

dude, you are /so/ freakin' twisted. if they're using it for re-bar,
you can be damned sure they're _not_ going to notice the difference -
other than wasting money of course. if they're using it for elevator
rope wire, you can be sure they will - and it's money well spent.

and you've just contradicted yourself on dates.
 
Peter Cole wrote:
<snip for clarity>
>
> >> "One plant has been making over 1.2 million tons of degassed sheet
> >> steel to supply the automotive market" (annual).
>
> Given that the US annual vehicle production is around 15M, just that one
> plant would be contributing around 200lb of *sheet* to the average vehicle.

and as i said earlier, for a 3,000lb vehicle, it's /clearly/ not being
used for /all/ the material.


>
>
>> and even then, not every manufacturer would be interested. it would
>> be great for forged cranks for example, but the majority of producers
>> cast cranks because it's so much cheaper - fatigue benefits of
>> superior materials be hanged.
>
> http://tinyurl.com/ywqhhy

what part of "Racing Crankshaft" is hard to comprehend as being atypical
when we're talking about using cast iron for cheap ****?


>
>
>> as for chronology, the benefits have been known for a long time -
>> since the 30's i believe, but knowing about it, being able to produce
>> it, and /paying/ for it are all completely different things. i don't
>> believe that an auto industry that will save 6' of copper wire by
>> using the same bulb for brake lights and turn signals, or not using
>> washers/gaskets on spark plugs, has the /slightest/ interest in paying
>> extra for vacuum degassed steels when cheap cast iron **** will do.
>
> Well, you're entitled to your beliefs, but it seems you are wrong.

eh? wrong like trying to ******** about racing cranks being used in
everyday vehicles is wrong?

>
> As for vacuum degassing being somehow cost prohibitive for bicycle
> spokes, consider that even at an extra $100/ton, the change in raw
> material costs would be less than a dime for a bike's worth of spokes.

er, you need to check out http://www.steelonthenet.com/steel_cost_bof.html

if i'm paying $261.50 per ton for steel, paying an extra 38% to get it
degassed is kind of significant.
 
jim beam wrote:
> Peter Cole wrote:
>> jim beam wrote:
>>
>> [vacuum degassed steel]
>>
>>> as for chronology, the benefits have been known for a long time -
>>> since the 30's i believe, but knowing about it, being able to produce
>>> it, and /paying/ for it are all completely different things. i don't
>>> believe that an auto industry that will save 6' of copper wire by
>>> using the same bulb for brake lights and turn signals, or not using
>>> washers/gaskets on spark plugs, has the /slightest/ interest in
>>> paying extra for vacuum degassed steels when cheap cast iron ****
>>> will do.
>>
>> An interesting report from *1966*:
>> <http://stinet.dtic.mil/oai/oai?&verb=getRecord&metadataPrefix=html&identifier=AD0803703>
>>
>>
>> "VACUUM-DEGASSED STEELS FROM THE CONSUMER'S VIEWPOINT
>>
>> Numerous industrial users were asked for their appraisal of
>> vacuum-degassed steel. Their responses regarding the merits of this
>> vacuum treatment were varied. ...
>>
>> Unfortunately, many of the users could not give a meaningful
>> evaluation because they knew that frequently their suppliers filled
>> orders with vacuum-degassed steels even though such treatment was not
>> specified."
>>
>> Sounds like cost wasn't a deal breaker even in 1966.
>
> dude, you are /so/ freakin' twisted. if they're using it for re-bar,
> you can be damned sure they're _not_ going to notice the difference -
> other than wasting money of course. if they're using it for elevator
> rope wire, you can be sure they will - and it's money well spent.

You missed the point (deliberately?). Cost wasn't an issue in 1966.

>
> and you've just contradicted yourself on dates.

How's that?
 
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