ok, hands up

jim beam said:

hands up all those that feel free to criticize a piece of equipment they've never tried. anyone?

That axe sharp enough yet?

When you talk about Jobst it might be wise to put his name in the post - I've little taste for
veiled asides along the lines of; "Don't you hate people who aren't even literate enough to use
capitals?"
--
David Damerell <[email hidden]> flcl?

Art Harris said:

jim beam said:

why do people do it?

I don't know. Why do you use different names in every ng you post to?

Oh, details, please! This way lies sock-puppetry.
--
David Damerell <[email hidden]> flcl?

jim beam said:

quick survey:

hands up all those that feel free to criticize a piece of equipment they've never tried. anyone?

further example: criticism of new materials outside the experience of the author and/or based on
erroneous "facts" is a particularly interesting phenomenon.

why do people do it? seriously, i'm genuinely interested by this. any thoughts?

jb

Well to use a really bad analogy... So we have three houses for sale.. one each made of Bricks -
Sticks - Straw

do you need to have lived in each type before describing the relative merits?

What if the Straw house had a whole lot of marketing hype about how it was "A revolutionary new
concept designed to have the best R-value of any house on the market!" "Save thousands on your
energy bills!"

Jim-<< hands up all those that feel free to criticize a piece of equipment they've never tried.
anyone? >><BR><BR>

Never been pregnant, don't want to be....

Peter Chisholm Vecchio's Bicicletteria 1833 Pearl St. Boulder, CO, 80302
(303)440-3535 vecchios.comvecchios.comOpen ↗ "Ruote convenzionali costruite eccezionalmente bene"

jim beam said:

hands up all those that feel free to criticize a piece of equipment they've never tried. anyone?

Sure. Anyone acting on logic considerations and basic (scientific) knowledge will.

--
MfG/Best regards helmut springer

I never drove a Pinto with an exploding gas tank.

I don't smoke.

I never used a Dalcon Shield IUD.

There is no asbestos insulation in my house.

If someone were to offer me some heroin, I probably wouldn't try it. But if I did, I would want some
assurance that it had not been cut with rat poison.

There's lots of stuff that I can criticize without having tried it personally.

Duffy

enough!

i love the middle age male concept!

i particularly like the houses of bricks, sticks & straw analogy. on the east coast of course,
bricks are fine. here on the west, bricks are a no-no because of seismic activity, so we build from
sticks. and in the europe, there are houses with straw roofs, so that is an excellent illustration
of something being unacceptable to one person but the only way forward for another. just as long as
the opinions of each group are respected and relevant facts observed.

thanks again folks.

jb

Quoted message said:

We have plenty of folks here who do not BS, qualify their comments and show evidence to
substantiate their claims.

jobst, i got to hand it to you - you have the biggest brass gonads i've ever seen. how you can make
a statement like that, suggesting by implication of course that /you/ just happen to be a shining
example of this exemplary behavior, just amazes me. how do you do it?

* you are the guy that can't differentiate between materials that exhibit strain aging from
those that don't, yet holds himself up to be a materials expert, complete with new fatigue
analysis theories.

* you are the guy that doesn't know enough to show the appropriate stress/strain graphs when
discussing the properties of materials in his own publication. [see point above.]

* you are the guy that hits on one of many possible explanations for cracking failures in rims
but can't be bothered to check whether the one you've thrown your weight behind is indeed the
real cause.

* you are the guy that states that all silver ma2 rims are unanodized, regardless of contrary facts
presented in the manufacturers own catalogs.

[there's more, but i've made my point]

please, give us a break!

as bill has very astutely observed earlier in this thread, _you_ are the guy that has that has the
remarkable ability to twist one argument into another as though the facts of one support the
supposition of the other. and here you are doing it again!

look, we're all entitled to opinions and this is an open forum, but please quit this "fact supports
supposition" and "opinion = fact" stuff. particularly when you're out of your own personal
experience or knowledge boundries! you have a valid contribution to make - your book is quite handy
in some respects, but it's not all technically correct, and some of the stuff you write here is just
plain fantasy. just enough fact thrown in of course to make it sound credible, but fantasy
nonetheless.

please, try to look beyond any "personal" element of someone's disagreement and understand that as
experienced and expert in some issues as you may be, it is possible that there are others where you
are not. particularly if it's new materials outside your expertise! making a general statement about
carbon fork failure for example does not have any relevance to its vibration damping properties.
sure, particularly early on, carbon forks did fail!! and if you don't want to ride one because of
that risk, that's absolutely fine. but don't extend that one fact into _supposition_ about there not
being any difference in ride quality because it's simply not true!

looking back through the archives, man, you've had some real doozies of arguments with people who've
apparently had valuable contributions to make, yet because you've stuck your neck out in defense of
whatever position you've taken, you just keep savaging them till they go away - regardless of their
worth. and a lot of them don't return. this forum is sadly impoverished by that in my opinion.
unfortunately, you seem to take their departure as vindication and confirmation of your
"correctness" and you therefore continue to fling odure at whoever comes along next and simply
repeat the whole ghastly business all over again.

suggestion: let's just get along. not every innovation is a personal affront. manufacturers are not
/all/ out to rip us off. someone pointing out a contrary argument is not necessarily a /personal/
attack requiring a "death or glory" defense. just take it easy. share the wisdom [& facts] you /do/
have and enjoy the learning of what you don't.

jb

[email hidden] (Art Harris) wrote in message
news:<[email hidden]>...

Quoted message said:

jim beam said:

why do people do it?

I don't know. Why do you use different names in every ng you post to?

Are you basing that on his email address, [email hidden]? That's the Federal Trade Commission's address
for unsolicited commercial email. I suspect that "jim beam" is trying to punish spammers who harvest
addresses from newsgroups. He's probably not the only one to use that tactic. So it may be unfair to
accuse him of using aliases.

"Duffy Pratt" <[email hidden]> wrote in message
"]news:[email hidden]...\

Quoted message said:

I never drove a Pinto with an exploding gas tank.

I don't smoke.

I never used a Dalcon Shield IUD.

There is no asbestos insulation in my house.

If someone were to offer me some heroin, I probably wouldn't try it. But

if

Quoted message said:

I did, I would want some assurance that it had not been cut with rat

poison.

Obviously not a mountain biker.

Bill "how MUCH rat poison?" S.

Quoted message said:

Never been pregnant, don't want to be....

Peter Chisholm

This is a Good Thing - we'd have a heck of a job finding a volunteer to get you that way...

Peter "never miss a cheap shot" Headland

In article said:

i particularly like the houses of bricks, sticks & straw analogy. on the east coast of course,
bricks are fine. here on the west, bricks are a no-no because of seismic activity, so we build
from sticks. and in the europe, there are houses with straw roofs, so that is an excellent
illustration of something being unacceptable to one person but the only way forward for another.

Check out straw bale houses, an increasingly popular building technique.

In article <[email hidden]>, [email hidden] (Jeff

Wills) said:

"swamprun" <[email hidden]> wrote in message
news:<[email hidden]>...

Quoted message said:

I have noticed the same thing. The recumbent riders seem to have an almost religious zeal for
their machines, but few facts about riding them.

Well, yes... in many cases, switching to recumbent bike allows a dedicated rider to continue
riding a bicycle for many years after the pain of upright riding precludes further cycling.
Whether that pain is caused by maladjustment of the bicycle or improper equipment choices is a
subject worthy of a college course, not a usenet posting.

You write this as though "the pain" is an inevitable consequence of riding s standard bicycle.
Frankly, for rides under about 100 miles, I think that if you have pain there is something wrong. It
may be something wrong with equipment selection, adjustment, fit or it may be something wrong with
the rider (fitness, preparedness, medical problem, etc). In almost all cases, "the pain" is likely
to be a correctible problem.

In my observations, one of the greatest causes of "the pain" in riding a standard bike is 50 year
old potbellied men trying to ride in Chris Boardman's position on a bike 4 sizes too small, sold to
them by the 22 year old Cat 1 racer working part-time at the bike shop so he can buy parts cheap.

I know one person who switched to a recumbent because of neck problems (herniated disk). His neck
only hurts and his hands only go numb when he hyperextends his neck, so he switched to a recumbent
and has had not further problems. However, he noted that there's still butt discomfort- it's just
different than the discomfort sometimes associated with traditional bike saddles.

In article said:

Quoted message said:

We have plenty of folks here who do not BS, qualify their comments and show evidence to
substantiate their claims.

jobst, i got to hand it to you - you have the biggest brass gonads i've ever seen. how you can
make a statement like that, suggesting by implication of course that /you/ just happen to be a
shining example of this exemplary behavior, just amazes me. how do you do it?

<snip>

Nice call, David.

swamprun said:

Alas, recumbent zealots don't seem to understand how to discuss the topic of velocity in objective
terms. Perhaps they have something to hide.

It seems to me that they sometimes have more fun.

That's as valid as increased speed, though they ought to just say it that way...

--
Rick Onanian

jim beam <[email hidden]> writes:

[snip]

Quoted message said:

* you are the guy that can't differentiate between materials that
* exhibit strain aging from those that don't, yet holds himself up to
* be a materials expert, complete with new fatigue analysis theories.

Can you explain why you think that this is relevant? I am familiar with strain aging in several
alloy systems, and can't figure out why you keep bringing this up.

Eager to learn...

Dave Korzekwa

Quoted message said:

Can you explain why you think that this is relevant?

sure. in recent threads, jobst has been talking about plastic deformation in spokes [particularly in
relation to butted spokes] without any accompanying work hardening.

umeciv.maine.edutension steel lx.jpgOpen ↗

this graph shows 3 primary zones:

1. elastic - the straight angled line

2. a spikey horizontal zone where the the material is deforming but not work hardening - as is
typically found in mild steel and some titanium alloys

3. plastic [work hardening] in a curving line up to u.t.s.

strain aging is zone 2, exactly as per jobst's description, and indeed, this is the form of graph he
uses when discussing the properties of materials in his book.

the trouble is, stainless steel, high strength steels/titaniums and aluminum alloys [the stuff bikes
are made from] _don't_ exhibit this property. they have a stress/strain graph more like this:

umeciv.maine.edutension alum ss.jpgOpen ↗

which only really has zones 1 & 3. once you get into the plastic deformation zone, you're work
hardening.

at the /back/ of jobst's book however, there /are/ results from some real life spoke tension tests,
all _exactly_ like this latter graph, none exhibiting strain aging. i find it hard to understand the
confusion.

that's why i think it's relevant: he's using the theory of one to support his assertion of behavior
in the other, even though his own tests don't support it.

jim beam said:

Quoted message said:

Can you explain why you think that this is relevant?

sure. in recent threads, jobst has been talking about plastic deformation in spokes [particularly
in relation to butted spokes] without any accompanying work hardening.

I assume that you are talking about the stress relieving step in wheel building. Before I ever heard
of "the book" I was familiar with stretching to relieve stress in sheets, plates and bars formed by
cold working. The concept is pretty well known, and there is even temper designations for aluminum
alloy products that are stress relieved this way (T51 and T52). The plastic strains required are
very small, on the order of the elastic strain at yield. For that reason the work hardening curve of
the material is pretty much irrelevant. When stress relieving spokes it is unlikely that the entire
cross section at any point would go plastic.

In the absence of any other theory why Jobst's and similar techniques seem to work, I believe it is
very likely to be accurate. The general concept works whether you ignore work hardening or not. I
don't know if Jobst ever said that the material does not work harden. I doubt that he claims to have
invented that general method of stress relief, and I am pretty sure he does not claim to be a
material scientist. He probably was the first to recognize the principal in bicycle spokes and
publish it. Even a mere mechanical engineer can recognize and use the concept.

[remaining description of stress-strain curves deleted]

Dave Korzekwa

Quoted message said:

In the absence of any other theory why Jobst's and similar techniques seem to work, I believe it
is very likely to be accurate.

had an interesting discussion with mike prime on this subject:

google.comgroupsOpen ↗
497,1035850616,1035780825,1035426344,1035277800,1034997547,1034837747,1034583400,1033628218,1012082-
330,1012049533&seekm=a6ac46b4.0308270639.a12f4d0%40posting.google.com#link12

mike's convinced me that the residual stress of wheel building, at least as far as the spoke elbow
is concerned, [the most likely failure point] is actually tensile, not compressive. tensile residual
stress at this point /should/ make fatigue more likely, not less. and /further/ bending at this
point from stress relief, as described by mike, is going to make the problem worse, not better.

so why don't we see more failures? better materials & improved manufacturing have a major influence.

also, there is no doubt in my mind, the methods described by jobst [& others] improve build quality.
a loose spoke is going to move about and fatigue. the "stress relief" building method pretty much
eliminates post-ride spoke loosening by getting it all sorted out in the build phase. and we know
this is true because "stress relieved" wheels stay true pretty much for the life of the wheel.

Tim McNamara <[email hidden]> wrote in message
news:<[email hidden]>... <snipped>

Quoted message said:

You write this as though "the pain" is an inevitable consequence of riding s standard bicycle.
Frankly, for rides under about 100 miles, I think that if you have pain there is something wrong.
It may be something wrong with equipment selection, adjustment, fit or it may be something wrong
with the rider (fitness, preparedness, medical problem, etc). In almost all cases, "the pain" is
likely to be a correctible problem.

You're putting words into my mouth. That's really unfair.

I've been riding regularly for 30 years, experimented with a variety of equipment, fitting
techniques, and conditioning on uprights before switching. Recumbents *in general* are the only
bikes that I can ride comfortably for long distances, regardless of conditioning.

Quoted message said:

In my observations, one of the greatest causes of "the pain" in riding a standard bike is 50
year old potbellied men trying to ride in Chris Boardman's position on a bike 4 sizes too small,
sold to them by the 22 year old Cat 1 racer working part-time at the bike shop so he can buy
parts cheap.

Well, that's not the fault of the recumbent folks. In fact, that kind of "sales" will drive people
to seek out radical solutions (like recumbents) when minimal adaptation (tall stem, wider saddle)
might allow them to continue to ride an upright.

Quoted message said:

I know one person who switched to a recumbent because of neck problems (herniated disk). His neck
only hurts and his hands only go numb when he hyperextends his neck, so he switched to a recumbent
and has had not further problems. However, he noted that there's still butt discomfort- it's just
different than the discomfort sometimes associated with traditional bike saddles.

I can sympathize with that person- I compressed a couple disks in my neck taking a header many
years ago. I can't hold my head up, even from a moderate "touring" position, for more than an hour
at a time.

Also, "recumbent butt" is a well-worn discussion in recumbent circles. IMO (that's "opinion"😉 it's
related to seat adjustment- something that requires lots of experimentation to find the "sweet spot"
between leg length adjustment, seat bottom angle, and seat back angle. Most people aren't willing to
play with their seat adjustment to the degree required to eliminate "recumbent butt".

(I'm aware that there are professional bike fitters. There's also professional recumbent bike
fitters- but they're few and far between.)

I'd like to continue this- but I'm off for Cycle Oregon tomorrow morning. I'll be doing a leisurely
400 miles worth of riding through the Blue and Wallowa Mountains of Eastern Oregon... on my Tour
Easy recumbent.

Jeff Wills