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Cycling Equipment
Published
4 July 2007
Last activity
15 July 2007
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wishful thinker
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  1. "Knight of Starlight" <[email hidden]> wrote in message
    news:[email hidden]...

    Quoted message said:

    Thank you for responding to my question. Bruce....I have two questions
    for you.
    1st...you mentioned the durability of your super light bike. Do you mean
    that carbon frames are not as durable as steel or aluminum?

    2nd....you mention a frame fromTawain. I was in my local bike shops
    today and they sold Trek, Specialized, and Giant. I noticed on all three
    brands "Made in Tawain". I was very surprised to see that among such
    reputable companies. Is that common for most bikes sold in the USA to me
    made there?

    I am looking to get a flat bar bike and found one on the internet I like
    alot...the Giant CRX 1. Unfortunately, it is not sold in my local bike
    shops.


    To risk a barrage of flames and focused hate, let me say this. I like the
    feel of carbon frames. Me, not anyone else, just me. In 1976 I broke my back
    in two places. The harmonic coming up out of many aluminum frames makes my
    body uncomfortable. Titanium and steel are better. But, carbon seems to
    deaden the road vibration enough where I can ride in comfort.

    I have seen aluminum bikes crack, the same for carbon, and steel too. It is
    going to be a combination of how you ride, where you ride, how much you
    weigh, who made the frame and when, and plain old luck. Even the most
    lightweight bikes are still pretty tough. Today, there is so much great
    stuff available it is unreal.

    I have a 5500. I like it a lot. Over the years there have been a few
    problems with them. Trek always took care of the issues and did it well. Is
    the 5500 any better than other frames? I don't really know, but as I said,
    Trek has done a great job for me.

    There are dozens of Taiwan and Mainland carbon bike companies in the Taiwan
    Bike Guide each year. Each year at the show we get a new book and the
    players have changed. But, there are so many companies that source from
    Taiwan and Mainland OEMs it is amazing.

    If you're going to get any bike, make sure you are going to get the support
    you want from both the dealer and the manufacturer. That is a key issue.
    Most of the bigger name companies are pretty good with customer service
    issues.

    Make sure the shop spends the time to get the bike fit correct. The greatest
    machine in the world will never work well for you if the frame sizing and
    fit is not on the money.

    My personal feeling about carbon frames and forks is they are all going to
    break. It is only a matter of when. That said, it could be three weeks, or
    it could be 20 years. I'm not so good with the psychic stuff these days...

    If I decide to get an OEM frame, I do it with the knowledge that many of
    these companies can be tough to deal with on warranties. Usually you have to
    ship the frame overseas and wait. Lots of the OEMs start mumbling about two
    year warranties right off the bat. If I was to develop a new bike line,
    there would have to be a replacement stock built into the business plan. You
    can't put customers through that kind of insanity.

    Maybe one of the more knowledgeable folks out there can advise us if a
    monocoque frame can be adequately repaired.

    I have no experience with the flat bar road bike you described. I did see
    that the Shimano book shows specific road shifters for them. I assume they
    are derived from an MTB design.

    Best Regards,

    Bruce

  2. Knight of Starlight said:

    ...
    2nd....you mention a frame fromTawain. I was in my local bike shops
    today and they sold Trek, Specialized, and Giant. I noticed on all three
    brands "Made in Tawain". I was very surprised to see that among such
    reputable companies. Is that common for most bikes sold in the USA to me
    made there?...

    Almost all the cheap bicycle shaped objects (and some better quality
    bikes) are now made in mainland [1] China due to the almost free labor.
    The Taiwanese now mostly make entry to mid-level bike store quality
    bikes, employing modern production equipment and methods, with
    relatively well paid workers. In general, Taiwanese bicycles have good
    quality TIG welds (done by robots?) and quality powder-coating.

    [1] Sorry Jobst.

    --
    Tom Sherman - Holstein-Friesland Bovinia
    The weather is here, wish you were beautiful

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

  3. DI said:

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

    Quoted message said:

    On Jul 7, 9:23 pm, "Bill Sornson" <[email hidden]> wrote:

    Quoted message said:


    I attribute those sorts of arguments to you, and to your cohort
    "Ozark." You two have routinely indulged in eighth-grade insults,
    although you seem to think yours are amazingly witty. Ozark tries
    for venom, not wit.

    Perhaps we should add the anonymous "DI" to the list?

    But no, Bill, your quip above doesn't have much wit, nor much value.
    It's just another of the insults you routinely spew.

    - Frank Krygowski

    You don't think it would be stupid to stand by a train track and ram
    your head into the train just to prove you could get it an inch
    closer without a helmet?

    Frank's an /intellectual/, DI. We can't be expected to appreciate his
    complexity.

    Bill "either that or he's just hung-over from his trip" S.

  4. Johnny Sunset aka Tom Sherman said:

    Bill Sornson wrote: {context removed; shock et surprise, n'est-ce pas?}

    Quoted message said:

    ...

    Quoted message said:
    Quoted message said:

    So fine, ride without a lid. Who's stoppin' ya?

    Quoted message said:

    In quite a few jurisdictions, the police would, due to the lies of the
    pro-helmet propagandists on the effectiveness of foam hats on
    preventing serious injury and death.

    So work against MHLs and stop attacking people who merely choose to wear
    helmets.

    Bill "problem solved; off you go" S.

  5. Bruce Gilbert said:

    To risk a barrage of flames and focused hate, let me say this. I like
    the feel of carbon frames. Me, not anyone else, just me. In 1976 I
    broke my back in two places. The harmonic coming up out of many
    aluminum frames makes my body uncomfortable. Titanium and steel are
    better. But, carbon seems to deaden the road vibration enough where I
    can ride in comfort.

    You better study some statistics and population studies! This is rbt!

  6. In article
    <[email hidden]>,

    Tim McNamara said:

    In article <[email hidden]>,

    Michael Press said:

    In article
    <[email hidden]>,

    Tim McNamara said:

    In article <[email hidden]>,
    Michael Press <[email hidden]> wrote:

    > In article <[email hidden]>,
    > Tim McNamara <[email hidden]> wrote:
    >
    > > In article <[email hidden]>,
    > > Michael Warner <[email hidden]> wrote:
    > >
    > > > On Fri, 06 Jul 2007 22:26:24 -0500, Tim McNamara wrote:
    > > >
    > > > > Yes. Impinged nerve running down into my left shoulder. It
    > > > > gets aggravated sometimes and wearing a helmet is one thing
    > > > > that does it pretty regularly.
    > > >
    > > > I'm sorry to hear it, but given the weight of a modern helmet
    > > > compared to your head, I'm skeptical. My bet is that it's due to
    > > > a different posture or muscle tension when you wear a helmet -
    > > > you're probably ducking into the wind, unconsciously trying to
    > > > minimize its extra wind resistance.
    > >
    > > Hard to say why it causes pain, my current helmet is the lightest
    > > that I could find and it's a little better but I still get more
    > > pain than if I don't wear it. And since I don't see benefit in
    > > wearing a helmet and have definite negative consequences, I often
    > > don't wear a helmet. I am more likely to wear one when riding with
    > > friends since they tend to be pro-helmet and I'd rather not waste
    > > riding time on the discussion.
    >
    > What kind of friend is that?

    Friends who have bought the marketing. They are well-meaning and
    genuinely concerned- most of these have acquired these tendencies
    through USCF racing and from Bicycling Magazine, among other sources.
    Why alienate them over something that doesn't inconvenience me all that
    much?

    Then be their friend.
    Wear a cloth cap and blast them if they try to give you [censored].
    Friends do not let friends get away with being a jerk.

    They aren't being jerks about it, Michael.

    If you are doing something because you do not want to
    deal with what they have to say, something that you
    would not do otherwise, then what is going on?

    --
    Michael Press

  7. DI said:

    <[email hidden]> wrote in message

    news:[email hidden]...

    Quoted message said:

    On Jul 7, 9:23 pm, "Bill Sornson" <[email hidden]> wrote:

    Quoted message said:

    I attribute those sorts of arguments to you, and to your cohort
    "Ozark." You two have routinely indulged in eighth-grade insults,
    although you seem to think yours are amazingly witty. Ozark tries for
    venom, not wit.

    Quoted message said:

    Perhaps we should add the anonymous "DI" to the list?

    Quoted message said:

    But no, Bill, your quip above doesn't have much wit, nor much value.
    It's just another of the insults you routinely spew.

    Quoted message said:

    - Frank Krygowski

    You don't think it would be stupid to stand by a train track and ram your
    head into the train just to prove you could get it an inch closer without a
    helmet?

    Here's the replay, "DI", with more detail.

    We frequently hear this argument, or ones just like it: "Ram your
    helmeted head into a wall. Then take off the helmet and ram your bare
    head into the wall. The second hurts more, so it proves beyond a
    doubt that you should always wear a helmet while biking." The post I
    was responding to was a very slight variation on that theme.

    One (just one) thing that "logic" fails to take into account is that
    the helmeted head is a bigger target. There _must_ be near misses of
    bare heads that would be converted to serious impacts of a helmet. In
    fact, given the evolutionary process, there's a good chance that our
    reflexes and muscle strength are _just_ adequate to keep our heads
    protected at the size they are naturally.

    Again, my teenaged fall (straight backward, on ice) would have very
    strongly impacted a helmet, but it barely touched my bare head.
    (Well, actually, I wore a stocking cap.) If I'd had a helmet on, it
    might have generated a "My helmet saved my life!" story. Another
    false one, that is.

    But that was a linear impact. Things are likely worse for a
    tangential impact. Again, given evolution (...apologies to the non-
    believers...), there is probably protective value in our hair and
    scalp tissue that easily slides in a grazing impact, even though it's
    messy. Styrofoam probably has a much higher coefficient of friction
    than hair and scalp tissue, even if the styrofoam is covered with a
    0.020" microshell. Furthermore, adding radius to the head adds a
    longer lever arm for that grazing impact to give rotational
    acceleration to the brain - which is much more damaging than linear
    acceleration, due to shearing of internal arteries.

    So the linear protective effect of an inch of styrofoam does come with
    costs. There are going to be more impacts, both linear and
    rotational. And the rotational ones are likely to be more damaging
    than before.

    Understand, I didn't come up with this on my own. It's been very
    seriously proposed as a major explanation for the observed fact, that
    strapping helmets on an entire population of cyclists does not reduce
    serious head injury rates. It's not the only possible explanation,
    but personally, I think it's a likely contributor.

    - Frank Krygowski

  8. Tim McNamara said:

    In article <[email hidden]>,

    Quoted post said:

    On Jul 7, 3:36 pm, John Forrest Tomlinson <[email hidden]>

    Quoted message said:

    On Sat, 07 Jul 2007 13:08:28 -0700, "[email hidden]"

    Quoted message said:
    Quoted message said:

    <[email hidden]> wrote:
    >What the hell are you talking about? What stronger info are you
    >talking about? Once I cracked a helmet in half. had it not been
    >there my head would have been the next contact surface. what
    >stronger information is there that says that if my helmet wasn't
    >there my head would have survived the impact? I passed out and
    >woke up in the hospital 4 hours later.

    Quoted message said:
    Quoted message said:

    What information is there that the helmet helped? I just don't
    understand how the fact that something far weaker than your skull
    was damaged demonstrates anything. We could look at leather
    helmets or even a bag of jello and the fact that those things would
    be destroyed would suggest they help, by your logic.

    Quoted message said:
    Quoted message said:

    Now, it's possible it did help. But we hear so many stories like
    yours that the only way the majority of them could be true would be
    if we were seeing unhelmeted people dying in scores. And we don't.

    Quoted message said:

    Are you familiar with something called a concussion. It is a serious
    blow to the head. It can cause anywhere from unconsciousness to more
    severe problems. I never said that the impacts to my helmet prevented
    my skull from cracking or exploding. I simply argued that it
    prevented more serious damage.

    It may have. It may not have. You believe that it did, but belief does
    not make things true.

    Quoted message said:

    the skull, as you probably know, has no organic function. It simply
    protects the brain.

    WTF? I guess you don't chew, talk, hear, smile or look around. This is
    one of the most ludicrous statements I have read in r.b.t.

    Quoted message said:

    a helmet is not necessarily designed to prevent the skull from
    exploding, as you, articulate types, put it. It adds another lawyer
    of protection to the brain. A blow to the head, without cracking your
    skull, can still kill you. The fact that there are more cracked
    helmets than cracked skulls doesn't mean that the helmets prevented
    skulls from cracking. It simply means that they prevented blows to
    the head which could have resulted in mild concussions or more severe
    and irreparable damage. the fact that you argue that there are so
    many cracked helmets implies that people fall on their head while
    riding. I think that those who were wearing a helmet and it cracked
    were pretty lucky to have been wearing one.

    That's a lot of couldas.

    Actually, the skull doesn't do any of the things that you list. It
    simply holds the organs, muscles, nerves, tendons, etc that allow
    those things to happen. The bones have structural function.

    Andres

  9. In article
    <[email hidden]>,

    Tim McNamara said:

    In article <[email hidden]>,

    Quoted post said:

    the skull, as you probably know, has no organic function. It simply
    protects the brain.

    WTF? I guess you don't chew, talk, hear, smile or look around. This is
    one of the most ludicrous statements I have read in r.b.t.

    I use my skull to keep out the bad ideas.

    --
    Michael Press

  10. In article <[email hidden]>,

    Bill Sornson said:
    Quoted message said:

    On Jul 7, 3:51 pm, "Bill Sornson" <[email hidden]> wrote:


    (about...?)

    Quoted message said:
    Quoted message said:

    I see the opposite -- especially on here. People (like Frank,
    Flailor, JFT, can't remember the rest) who don't just argue against
    lids, they badger and belittle those who choose to wear them.

    Quoted message said:

    :-) Shall we quote the mindless insults from you and Ozark AGAIN?

    Well yes, Frank, I dared to answer your pompous condescension with return
    insults. Probably even lost my temper a few times, before realizing with
    what I was dealing. Typical brainiac (self-described) quite sure his is the
    /only/ correct opinion.

    Whenever you read a measured contradiction of what you
    write, you call it pompous. To you, pompous means a
    style unlike the style you use; your style being thick
    with epithet and disrespect. You are addressed
    respectfully, and call it pompous. One day you will be
    treated as you treat others, but not here. You may look
    forward to a time when all your venal misrepresentations
    are visited upon you.

    --
    Michael Press

  11. Tim McNamara said:

    In article <[email hidden]>,
    "[email hidden]" <[email hidden]> wrote:

    Quoted message said:
    Quoted message said:

    the skull, as you probably know, has no organic function. It simply
    protects the brain.

    Quoted message said:

    WTF? I guess you don't chew, talk, hear, smile or look around. This
    is one of the most ludicrous statements I have read in r.b.t.

    Timmy doesn't know his skull from his face?

  12. Quoted message said:
    Bill Sornson said:
    Quoted message said:


    The problem, Bill, is that you see most attempts at logic and
    science as being pompous. "How dare that guy try to think
    logically?"

    Bull. I distinctly recall /many/ encounters with you where you say
    "well you refuse to learn" or "those who can't learn from their
    betters" or some such [censored]. It's condescending, period.

    Quote of one Bill Sornson, from this thread, yesterday, July 6, 2007:

    "The AHZs (anti-helmet zealots) refuse to listen to reason. You'll
    see."

    Yes, I said that to a new poster who is destined to bang his (thankfully
    lidded) head against a wall arguing with the likes of you. (Although IIRC
    it was someone else who was giving the poor [censored] grief.)

    Quoted message said:

    So who is condescending? Is that sort of remark forbidden except when
    you use it?

    It doesn't compare at all to "(I decree that) you lack critical thinking
    skills" or your other /personally directed/ insults. This was a generalized
    comment. Trust you can discern the difference in degree of offensiveness?
    (Oh well it was worth a shot.)

    I stupidly began to keep reading, and then remembered what a complete waste
    of time it is.

    Don't wear a helmet, Frank. I'll continue wearing one (along with about 90%
    of the cyclists I see).

    I'll give you credit for one thing: you are amazingly verbose on the
    subject. Seriously. Unless you're pasting boilerplate, you go ON AND ON
    AND ON AND ON AND ON AND ON AND ON AND ON AND
    ON..............................................

    BS out

  13. Michael Press said:

    In article <[email hidden]>,

    Bill Sornson said:
    Quoted message said:

    On Jul 7, 3:51 pm, "Bill Sornson" <[email hidden]> wrote:


    (about...?)

    Quoted message said:

    > I see the opposite -- especially on here. People (like Frank,
    > Flailor, JFT, can't remember the rest) who don't just argue against
    > lids, they badger and belittle those who choose to wear them.

    Quoted message said:

    :-) Shall we quote the mindless insults from you and Ozark AGAIN?

    Well yes, Frank, I dared to answer your pompous condescension with
    return insults. Probably even lost my temper a few times, before
    realizing with what I was dealing. Typical brainiac
    (self-described) quite sure his is the /only/ correct opinion.

    Whenever you read a measured contradiction of what you
    write, you call it pompous. To you, pompous means a
    style unlike the style you use; your style being thick
    with epithet and disrespect. You are addressed
    respectfully, and call it pompous. One day you will be
    treated as you treat others, but not here. You may look
    forward to a time when all your venal misrepresentations
    are visited upon you.

    If you don't consider Frank pompous, then you haven't been paying attention.
    Otherwise, nice one! <eg>

  14. In article <[email hidden]>,

    Quoted post said:
    Tim McNamara said:

    In article <[email hidden]>,

    Quoted post said:

    the skull, as you probably know, has no organic function. It
    simply protects the brain.

    WTF? I guess you don't chew, talk, hear, smile or look around.
    This is one of the most ludicrous statements I have read in r.b.t.


    Actually, the skull doesn't do any of the things that you list. It
    simply holds the organs, muscles, nerves, tendons, etc that allow
    those things to happen. The bones have structural function.

    You're splitting frog's hairs here, Andres.

  15. In article <[email hidden]>,

    Bill Sornson said:
    Tim McNamara said:

    In article <[email hidden]>, "Bill

    Sornson said:

    Tim McNamara wrote:
    > In article <[email hidden]>, "Bill
    > Sornson" <[email hidden]> wrote:
    >
    >> Tim McNamara wrote:
    >>> In article <[email hidden]>, "Bill
    >>> Sornson" <[email hidden]> wrote:
    >>
    >> {Note all context removed. It's pathological!}
    >>
    >>>> Wearing a helmet /does/ make one at least somewhat safer;
    >>
    >>> Which is a belief not an established fact.
    >>
    >> A) It's common sense;
    >
    > Common sense means "I already know what's true, don't confuse me
    > with the facts." If common sense worked, we wouldn't need
    > science.

    No, common sense is if I hit a table with a hammer the impact will
    be harder if I don't put down a pad first. (It's called a BARRIER
    or BUFFER, you see.)

    Thanks for proving my point so eloquently.

    Tell you what. Prove that a hammer has less impact on a table with
    no pad in place and I'll retract every word. Hell, I'll even stop
    wearing a lid! (Maybe.)

    Force = mass * acceleration.

  16. In article <[email hidden]>,

    Michael Press said:

    In article <[email hidden]>,

    Tim McNamara said:

    In article
    <[email hidden]>,

    Michael Press said:

    In article <[email hidden]>,
    Tim McNamara <[email hidden]> wrote:

    > In article
    > <[email hidden]>,
    > Michael Press <[email hidden]> wrote:
    >
    > > In article <[email hidden]>,
    > > Tim McNamara <[email hidden]> wrote:
    > >
    > > > In article <[email hidden]>,
    > > > Michael Warner <[email hidden]> wrote:
    > > >
    > > > > On Fri, 06 Jul 2007 22:26:24 -0500, Tim McNamara wrote:
    > > > >
    > > > > > Yes. Impinged nerve running down into my left
    > > > > > shoulder. It gets aggravated sometimes and wearing a
    > > > > > helmet is one thing that does it pretty regularly.
    > > > >
    > > > > I'm sorry to hear it, but given the weight of a modern
    > > > > helmet compared to your head, I'm skeptical. My bet is
    > > > > that it's due to a different posture or muscle tension
    > > > > when you wear a helmet - you're probably ducking into the
    > > > > wind, unconsciously trying to minimize its extra wind
    > > > > resistance.
    > > >
    > > > Hard to say why it causes pain, my current helmet is the
    > > > lightest that I could find and it's a little better but I
    > > > still get more pain than if I don't wear it. And since I
    > > > don't see benefit in wearing a helmet and have definite
    > > > negative consequences, I often don't wear a helmet. I am
    > > > more likely to wear one when riding with friends since they
    > > > tend to be pro-helmet and I'd rather not waste riding time
    > > > on the discussion.
    > >
    > > What kind of friend is that?
    >
    > Friends who have bought the marketing. They are well-meaning
    > and genuinely concerned- most of these have acquired these
    > tendencies through USCF racing and from Bicycling Magazine,
    > among other sources. Why alienate them over something that
    > doesn't inconvenience me all that much?

    Then be their friend. Wear a cloth cap and blast them if they try
    to give you [censored]. Friends do not let friends get away with being
    a jerk.

    They aren't being jerks about it, Michael.

    If you are doing something because you do not want to deal with what
    they have to say, something that you would not do otherwise, then
    what is going on?

    How is it that this is so difficult for you to understand? Are you this
    contentious with *your* friends? "What's going on" is that I choose not
    to make an issue out of everything with my friends. There are some
    things I rate as more important than others.

    As I have said before, I often wear a helmet when riding. It makes
    important members of my family happier (my mother, my wife, etc.).
    Other than aggravating my neck and making sweat run in my eyes on hot
    days, it doesn't inconvenience me. I have no expectation that it will
    provide me with protection nor that it will cause me harm, but the
    feelings of the people I care about are more important to me.

    I am much more contentious in these discussions than I am in person,
    because it's a "tech" newsgroup. In real life, someone as argumentative
    as most of us are here would soon have no friends. I overlook many
    foibles in my friends and vice versa, for the sake of those friendships
    unless the foible is clearly going to cause harm. I think it likely
    that you do the same.

  17. Tim McNamara said:

    So difficult that it is not show up under scientific scrutiny.

    Recent fall, Timmy? <eg>

  18. Michael Press wrote to me:

    Quoted message said:

    Whenever you read a measured contradiction of what you
    write, you call it pompous.

    Actually, I don't. The only people I recall calling pompous are Frank,
    Jobst, Fogey and possibly you. (Although I consider you more of a pedantic
    net nanny stick-in-the-mud, which is why your recent foray into HUMOR has
    been so refreshing!)

    Quoted message said:

    To you, pompous means a
    style unlike the style you use; your style being thick
    with epithet and disrespect. You are addressed
    respectfully, and call it pompous.

    Frank did not address me respectfully. If you knew anything about our
    history (and not just the last few days), you'd realize how wrong you are.

    Quoted message said:

    One day you will be
    treated as you treat others, but not here. You may look
    forward to a time when all your venal misrepresentations
    are visited upon you.

    Right back at you, Mr. Judgemental. One can only hope.

  19. Tim McNamara said:

    In article <[email hidden]>,

    Bill Sornson said:
    Tim McNamara said:

    In article <[email hidden]>, "Bill
    Sornson" <[email hidden]> wrote:

    > Tim McNamara wrote:
    >> In article <[email hidden]>, "Bill
    >> Sornson" <[email hidden]> wrote:
    >>
    >>> Tim McNamara wrote:
    >>>> In article <[email hidden]>, "Bill
    >>>> Sornson" <[email hidden]> wrote:
    >>>
    >>> {Note all context removed. It's pathological!}
    >>>
    >>>>> Wearing a helmet /does/ make one at least somewhat safer;
    >>>
    >>>> Which is a belief not an established fact.
    >>>
    >>> A) It's common sense;
    >>
    >> Common sense means "I already know what's true, don't confuse me
    >> with the facts." If common sense worked, we wouldn't need
    >> science.
    >
    > No, common sense is if I hit a table with a hammer the impact will
    > be harder if I don't put down a pad first. (It's called a BARRIER
    > or BUFFER, you see.)

    Thanks for proving my point so eloquently.

    Tell you what. Prove that a hammer has less impact on a table with
    no pad in place and I'll retract every word. Hell, I'll even stop
    wearing a lid! (Maybe.)

    Force = mass * acceleration.

    "Impact". Not "force". HTH!

  20. On Sun, 08 Jul 2007 01:23:09 -0500, Tim McNamara
    <[email hidden]> wrote:

    [snip]

    Quoted message said:

    I haven't got a bowling ball. Maybe we can get Fogel Labs to give it a
    try and video the results. Anybody got an old undamaged helmet or two
    to send to Carl?

    [snip]

    Dear Tim,

    Fogel Labs has no bowling equipment, but the experiment probably isn't
    worth pursuing.

    A head inside a helmet is practically guaranteed to fit without
    putting spreading pressure on the sides of the helmet.

    Heads are longer than they are wide--look at any reasonably
    well-fitting stiff hat. (Soft caps simply bend to fit the noggin.)

    In contrast, a bowling ball is round. If large enough, it should
    easily crack a typical bicycle helmet against the floor by acting as a
    blunt wedge.

    Most bicycle helmet manufacturers recommend replacing any helmet
    dropped on the ground, since they crack easily. Fewer and fewer
    bicycle helmets pass even the watered-down recent tests, none of which
    ever matched the force of a six-foot rider toppling over sideways
    after forgetting to unclip at a stop light.

    Curiously, toppling over sideways (as opposed to a free fall drop)
    produces a greater acceleration and impact for the end (or head) of
    the thing toppling.

    (This is why tall chimneys break as they fall. They're not stiff
    enough to accelerate the upper part without breaking. Think of a
    felexible rod--the end lags behind if you wave it.)

    As others have calculated in earlier threads, the far end of a
    toppling board hits the ground at 3/2 or 150% of the speed it would
    strike if dropped in free fall from the same height.

    Since kinetic energy for the same mass increases with the square of
    the velocity, this means 9/4 or 225% of the original impact energy of
    100%.

    An object (such as a severed head in a helmet) dropping free for the 5
    feet often mentioned will hit the ground at 17.93 feet per second, or
    12.2 mph.

    The same object falling over sideways on a pole (closer to how heads
    actually hit the ground when bike frames are between legs) will land
    at 3/2 that speed, about 27 feet per second, or 18.4 mph.

    http://hyperphysics.phy-astr.gsu.edu/hbase/traj.html

    Given the flexibility of the human body, actual impacts should be
    somewhat less than the rigid-pole example, but still noticeably
    greater than free fall.

    Cheers,

    Carl Fogel

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