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Crank lengths

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Australia and New Zealand
Published
13 April 2003
Last activity
22 April 2003
Original author
Ben Wight
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46
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  1. Hook, line and sinker lol

    here fishy fishy ;o)

    I rest my case :o)

    Jose Rizal said:


    John Staines:

    Quoted message said:

    Errr I don't think picking on his literary skills was warrented or added to the discussion.

    It's "literacy", not "literary". It's "warranted", not "warrented".

    Quoted message said:

    It just made you look abit silly and narky.

    It's "a bit", not "abit".

    Sorry, didn't know you two were related.

    Quoted message said:

    all IMHO of course. :o)

    Kind regards

    Jose Rizal said:


    Super Mario:

    > I mightbe generating more work, but the speed generated is more for the same amount I put in
    > genious!

    It's "genius", not "genious". And no, any engineering student can tell you that you're wrong,
    have no concept whatsoever of any physical laws and mechanics of solids; in fact, no
    understanding of engineering at all. "Engineering background" indeed... If you're going to
    make up things, at least read up a bit and make it read like you know what you're talking
    about.

    > All the formulas you put out are [censored]!

    Sorry, you can't dismiss the laws of physics just because you can't understand it.

    > It's the reality of the actua; experiment!

    Ah, on your make-believe world where the laws of physics do not apply? Of course, I see it
    now... chocolate streets and chocolate dogs, and a chocolate sale in a chocolate shop!

    > What I wrote is true.

    In the land of chocolates....

    > And I have made 190mm cranks in my workshop! Which I will use to race this weekend!

    And I have turned lead into gold! Which I will sell this weekend! I'll be rich, rich I tells
    ya....

    > there is no rule in stateing how long crank arms have to be!😠

    It's "stating", not "stateing", and it's "cranks", not "crank arms" (in every sense of the
    word).

    Your poor literacy skills and lack of any clue of the world around you highlight the comical
    claim you made of having a mechanical engineering degree and an engineering background. Go
    back to your room, little boy.

  2. "John Staines" <[email hidden]> wrote in message
    "]news:[email hidden]...

    Quoted message said:

    Errr I don't think picking on his literary skills was warrented or added to the discussion.

    It just made you look abit silly and narky.

    That maybe the case, but in view of the alleged Degree in Mechanical Engineering and the spurious
    statements made about the laws of physics it is just another factor in asessing the guy's
    authenticity.

    Cheers Peter

  3. Peter,

    I understand what your saying....I don't know much about the discussion.

    I'm not as educated as alot of you seem to be in this area of discussion etc

    The lad may well be winding you lot up....so why bite? I just didn't see the point of a
    personal attack.

    Peter Signorini said:


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

    Quoted message said:

    Errr I don't think picking on his literary skills was warrented or added to the discussion.

    It just made you look abit silly and narky.

    That maybe the case, but in view of the alleged Degree in Mechanical Engineering and the spurious
    statements made about the laws of physics it is just another factor in asessing the guy's
    authenticity.

    Cheers Peter

  4. John Staines:

    Quoted message said:

    Hook, line and sinker lol

    here fishy fishy ;o)

    I rest my case :o)

    Yes Mario, you're still wrong.

    Stand in the corner, little boy.

    Quoted message said:
    Jose Rizal said:


    John Staines:

    Quoted message said:

    Errr I don't think picking on his literary skills was warrented or added to the discussion.

    It's "literacy", not "literary". It's "warranted", not "warrented".

    Quoted message said:

    It just made you look abit silly and narky.

    It's "a bit", not "abit".

    Sorry, didn't know you two were related.

    Quoted message said:

    all IMHO of course. :o)

    Kind regards

    Jose Rizal wrote:
    >
    > Super Mario:
    >
    > > I mightbe generating more work, but the speed generated is more for the same amount I put
    > > in genious!
    >
    > It's "genius", not "genious". And no, any engineering student can tell you that you're
    > wrong, have no concept whatsoever of any physical laws and mechanics of solids; in fact, no
    > understanding of engineering at all. "Engineering background" indeed... If you're going to
    > make up things, at least read up a bit and make it read like you know what you're talking
    > about.
    >
    > > All the formulas you put out are [censored]!
    >
    > Sorry, you can't dismiss the laws of physics just because you can't understand it.
    >
    > > It's the reality of the actua; experiment!
    >
    > Ah, on your make-believe world where the laws of physics do not apply? Of course, I see it
    > now... chocolate streets and chocolate dogs, and a chocolate sale in a chocolate shop!
    >
    > > What I wrote is true.
    >
    > In the land of chocolates....
    >
    > > And I have made 190mm cranks in my workshop! Which I will use to race this weekend!
    >
    > And I have turned lead into gold! Which I will sell this weekend! I'll be rich, rich I tells
    > ya....
    >
    > > there is no rule in stateing how long crank arms have to be!😠
    >
    > It's "stating", not "stateing", and it's "cranks", not "crank arms" (in every sense of the
    > word).
    >
    > Your poor literacy skills and lack of any clue of the world around you highlight the comical
    > claim you made of having a mechanical engineering degree and an engineering background. Go
    > back to your room, little boy.

  5. Mr Signori (I hope thats how you spell it)

    What is your e-mail address and I will send youa copy of my degree!

    The fact of the matter is,

    A longer crank will generate more speed! I will also send you the plans I drew up when I made and machined the cranks!

    If you have any understanding of engineering, I would question it!

    Stick to your local job in garbology! I didn't attack anybody personaly, just the infomation.

    If you would like to qestion somebodys mentality, it should be your own!

    NUTJOB!:p

  6. Also mister garbologist, I have a bag of cans at home, how much refund do I get per kilo?

    F#$KWIT!

  7. Mr Garbologist ,

    I would also question your intelligence of cycling! If you want to be nasty, I can be nastier!

    Do you get confused as to which is the front and which is the back of the bike? I bet you do! Does your daddy adjust your training wheels for you little boy? I bet he does!
    Does mummy wipe the snot from your face from riding hard? I bet she does! Does your daddy help you on your bike? I bet he does!

    Look who is a little [censored] now, jerk*ff!😄

  8. Jose,

    It's "Yes John", not "Yes Mario" ;o)

    I was merely stating with my hook, line and sinker email, that you'd found all the errors in my
    intial email. Well done!

    Stop being so paranoid. It was meant to calm the situation down..you know abit of humour.

    I think your taking this all alittle to personally, Jose. You'll give yourself an ucler you know.

    Cheers

    John not Mario (well the last time I looked) :o)

    I wouldn't post this response to the list but I'm unable to do so privately.

    Jose Rizal said:


    John Staines:

    Quoted message said:

    Hook, line and sinker lol

    here fishy fishy ;o)

    I rest my case :o)

    , you're still wrong.

    Stand in the corner, little boy.

    Quoted message said:
    Jose Rizal said:


    John Staines:

    > Errr I don't think picking on his literary skills was warrented or added to the discussion.

    It's "literacy", not "literary". It's "warranted", not "warrented".

    > It just made you look abit silly and narky.

    It's "a bit", not "abit".

    Sorry, didn't know you two were related.

    > all IMHO of course. :o)
    >
    > Kind regards
    >
    >
    >
    > Jose Rizal wrote:
    > >
    > > Super Mario:
    > >
    > > > I mightbe generating more work, but the speed generated is more for the same amount I
    > > > put in genious!
    > >
    > > It's "genius", not "genious". And no, any engineering student can tell you that you're
    > > wrong, have no concept whatsoever of any physical laws and mechanics of solids; in fact,
    > > no understanding of engineering at all. "Engineering background" indeed... If you're going
    > > to make up things, at least read up a bit and make it read like you know what you're
    > > talking about.
    > >
    > > > All the formulas you put out are [censored]!
    > >
    > > Sorry, you can't dismiss the laws of physics just because you can't understand it.
    > >
    > > > It's the reality of the actua; experiment!
    > >
    > > Ah, on your make-believe world where the laws of physics do not apply? Of course, I see it
    > > now... chocolate streets and chocolate dogs, and a chocolate sale in a chocolate shop!
    > >
    > > > What I wrote is true.
    > >
    > > In the land of chocolates....
    > >
    > > > And I have made 190mm cranks in my workshop! Which I will use to race this weekend!
    > >
    > > And I have turned lead into gold! Which I will sell this weekend! I'll be rich, rich I
    > > tells ya....
    > >
    > > > there is no rule in stateing how long crank arms have to be!😠
    > >
    > > It's "stating", not "stateing", and it's "cranks", not "crank arms" (in every sense of the
    > > word).
    > >
    > > Your poor literacy skills and lack of any clue of the world around you highlight the
    > > comical claim you made of having a mechanical engineering degree and an engineering
    > > background. Go back to your room, little boy.

    --
    ******************************************************************************
    John Staines Acquisition Department Phone: 61 8 8303 5347 Barr Smith Library Fax: 61 8 8303 4369
    Adelaide University South Australia 5005 Australia

    Email: [email hidden] Alternate email: [email hidden]

    ******************************************************************************

  9. "Jose Rizal" <_@_._> wrote in message
    "]news:[email hidden]...

    Quoted message said:

    Your poor literacy skills and lack of any clue of the world around you highlight the comical claim
    you made of having a mechanical engineering degree and an engineering background. Go back to your
    room, little boy.

    If you really think about it, poor literacy skills and the lack of any clue whatsoever might lean
    in his favour in his claim to hold a B.Eng Mech 😉 Unfortunately the rest of what he said was
    just [censored].

    perhaps he should try something like:
    google.com.ausearch
    e=UTF-8&hl=en&btnG=Google+Search&meta= where there's plenty of discussions and reported experiments
    on crank length on the web, and from Lennard Zinn's work at:
    velonews.comcrank.html they say "Oddly enough, however, under some conditions,
    we consistently produced our highest power outputs with the shortest set of cranks we tested."
    Perhaps the trackies aren't all that mad after all...

    Gemma "I also is a injiner and i can evn spel it to" (165mm track crank, 175mm road crank.....)

  10. You could say that Mario is/was pedaling a crank email ;o) (thats a cracker)

    Did you hear the one about the Englishman.....

    I thank you

    John

    Gemma Kernich said:


    "Jose Rizal" <_@_._> wrote in message
    "]news:[email hidden]...

    Quoted message said:

    Your poor literacy skills and lack of any clue of the world around you highlight the comical
    claim you made of having a mechanical engineering degree and an engineering background. Go back
    to your room, little boy.

    If you really think about it, poor literacy skills and the lack of any clue whatsoever might lean
    in his favour in his claim to hold a B.Eng Mech 😉 Unfortunately the rest of what he said was
    just [censored].

    perhaps he should try something like:
    google.com.ausearch
    e=UTF-8&hl=en&btnG=Google+Search&meta= where there's plenty of discussions and reported
    experiments on crank length on the web, and from Lennard Zinn's work at:
    velonews.comcrank.html they say "Oddly enough, however, under some
    conditions, we consistently produced our highest power outputs with the shortest set of cranks we
    tested." Perhaps the trackies aren't all that mad after all...

    Gemma "I also is a injiner and i can evn spel it to" (165mm track crank, 175mm road crank.....)

  11. "Super Mario" <[email hidden]> wrote in message
    "]news:[email hidden]...

    Quoted message said:

    Mr Signori (I hope thats how you spell it)

    No!

    Quoted message said:

    What is your e-mail address and I will send youa copy of my degree!

    Hint: use the reply button and you'll find it, even the correct name spelling too.

    Quoted message said:

    The fact of the matter is,

    A longer crank will generate more speed! I will also send you the plans I drew up when I made and
    machined the cranks!

    Go right ahead.

    Quoted message said:

    If you have any understanding of engineering, I would question it!

    I make no personal claims - I am not an engineer. Some very basic knowledge of physical principles
    (ie. gears, pulleys & leverage) and an understanding of the concept of work, aided by my dad who is
    an engineer, enable me to raise a few questions. I notice you have not answered any of them.

    Quoted message said:

    Stick to your local job in garbology! I didn't attack anybody personaly, just the infomation.

    When did I attack you personally? Please quote it back to me. But you do seem to like making
    personal attacks.

    As far as I'm aware I have only questioned the accuracy of your claims to be able to achieve higher
    speeds with no greater work, simply an increase in leverage. This is the key point in contention.

    Cheers Peter

  12. "Super Mario" <[email hidden]> wrote in message
    "]news:[email hidden]...

    Quoted message said:

    Also mister garbologist, I have a bag of cans at home, how much refund do I get per kilo?

    F#$KWIT!

    Oops, sorry. Did I tread on your toe? Here, have a little sit down. Caalm those nerves, I'm only
    trying to discuss a cycling issue. Don't worry, I take it all back. You're really a cool,
    intelligent guy. Candidate for next year's TdF as well.

    Better now? Good.

    Cheers Peter

  13. Gemma Kernich:

    Quoted message said:

    perhaps he should try something like:
    google.com.ausearch
    e=UTF-8&hl=en&btnG=Google+Search&meta= where there's plenty of discussions and reported
    experiments on crank length on the web, and from Lennard Zinn's work at:
    velonews.comcrank.html they say "Oddly enough, however, under some
    conditions, we consistently produced our highest power outputs with the shortest set of cranks we
    tested."

    This seems to make sense, as in shorter cranks a force applied to produce the desired torque (and
    hence power) only needs to be applied over a shorter distance per revolution (shorter pedal travel
    circumference). That is, for a chosen cadence, the higher physical effort required from the rider to
    apply a larger force on the cranks to produce the highest torque possible only needs to be done over
    a shorter circumferential distance *per revolution*.

    In other words, it could be the case where it seems easier to apply the largest possible force the
    rider can muster consistently all the way through one complete crank revolution using shorter
    cranks, than to apply the same magnitude force consistently using longer cranks because shorter
    cranks mean shorter duration at which the rider has to produce this effort to complete one
    revolution. An analogy can be made with running flat out over x metres versus flat out over n * x
    metres (where
    n > 1). Depending on what n is, the runner might not be able to apply consistent maximum effort all
    the way to the finish the longer the distance.

    Of course, over many revolutions the rider's stamina will come into play no matter what length
    cranks but I think the testing wasn't done over long distances (rather in bursts).

    Quoted message said:

    Perhaps the trackies aren't all that mad after all...

    Where bursts of power are crucial...

    Quoted message said:

    Gemma "I also is a injiner and i can evn spel it to" (165mm track crank, 175mm road crank.....)

  14. Ben Wight said:

    I haven't checked out any referred links yet, so I still maybe talking out my ass!

    At least read Sheldon Brown. He is clear and to-the-point.

    --
    make nospam into oz to reply.

  15. "Jose Rizal" <_@_._> wrote in message > > Perhaps the trackies aren't all that mad after all...

    Quoted message said:


    Where bursts of power are crucial...

    As is leg speed.....

    And so is not hitting a pedal on the track, but there's another argument for shorter cranks.
    Interestingly though, I find my tires lose traction and slip from under me at low speeds before I go
    slow enough to slip a pedal, unlike some of the lightweights out there where the reverse is true.
    Perhaps we can get the other 'engineers' to calculate a bottom bracket height vs speed vs rider
    weight graph for a given set of pedals, cranks and tires, on a 250m banked track (43deg maximum
    slope). I would like my tires to slip at a speed just faster than would be required for me to clip a
    pedal. What bottom bracket height should I have? How bout it super mario? Only a few laws of physics
    to understand here.... I'll admit I'm an engineer, and I'm not going to be able to work it out in a
    hurry. Besides, I don't know the coefficient of friction between wooden boards and Conti Tempo 22's
    so I can't do it 😉

    Gemm 🙂

  16. Gemma Kernich said:

    velonews.comcrank.html

    Eureka! A real scientific test on an indoor machine. I In hindsight, you could probably pick a few
    faults. In particular, I think it was a mistake to use a constant 90rpm cadence, because shorter
    cranks should allow a higher cadence. It would be better to use constant pedal speed.

    More at cranklength.infocranklength.info

    Quoted message said:

    Gemma "I also is a injiner and i can evn spel it to" (165mm track crank, 175mm road crank.....)

    Gemma, how about finding someone to try the 175mm cranks on a track bike? Be sure to stand by with a
    camera to document the results, and post here!

    --
    make nospam into oz to reply.

  17. Mike:

    Quoted message said:
    Gemma Kernich said:

    velonews.comcrank.html

    Eureka! A real scientific test on an indoor machine. I In hindsight, you could probably pick a few
    faults. In particular, I think it was a mistake to use a constant 90rpm cadence, because shorter
    cranks should allow a higher cadence.

    Trying to maintain a set cadence while increasing resistance is the easiest way to measure effort on
    this test.

    Quoted message said:

    It would be better to use constant pedal speed.

    Constant pedal speed means constant angular velocity of the cranks, achieved only when there is a
    constant force on the pedals throughout the crank rotation. This is extremely difficult to achieve
    since force applied by the legs as they go through the range of circular motion of the cranks will
    vary according to leg position.

  18. Jose Rizal said:

    Trying to maintain a set cadence while increasing resistance is the easiest way to measure effort
    on this test.

    OK.

    Quoted message said:


    Quoted message said:

    It would be better to use constant pedal speed.

    Constant pedal speed means constant angular velocity of the cranks,

    Eh? constant angular velocity means constant cadence. 1 rad/s = 9.55 rpm

    I meant linear pedal speed, so use 3% shorter crank with 3% higher cadence.

    They would still maintain a set cadence, just adjusting from 90rpm for crank length.

    Quoted message said:

    achieved only when there is a constant force on the pedals throughout the crank rotation. This is
    extremely difficult to achieve since force

    huh?? I dont think anybody is talking that level of precision.

    --
    make nospam into oz to reply.

  19. Mike:

    Quoted message said:
    Quoted message said:


    Quoted message said:

    It would be better to use constant pedal speed.

    Constant pedal speed means constant angular velocity of the cranks,

    Eh? constant angular velocity means constant cadence. 1 rad/s = 9.55 rpm

    No, you can achieve constant cadence without having constant angular velocity within one revolution.
    Within one revolution, the crank angular velocity can (and in practice, does) vary, but as long as
    this variation in speed is consistent with each revolution, the cadence will stay the same. For
    example, the angular velocity may be at a peak when the cranks are horizontal with one leg pushing
    down and the other pulling up (with cleats or such, obviously), and it may be at a minimum when the
    cranks are vertical, but as long as this cyclic variation of angular speed happens within every
    revolution, the cadence will be (more or less) constant.

    Constant pedal speed, on the other hand, means that there are no variations in angular velocity
    within one revolution, a feat almost impossible to achieve (or at least maintain for any
    significant time).

    Quoted message said:

    I meant linear pedal speed, so use 3% shorter crank with 3% higher cadence.

    They would still maintain a set cadence, just adjusting from 90rpm for crank length.

    I don't think the results will then be comparable between different crank lengths.

    Quoted message said:
    Quoted message said:

    achieved only when there is a constant force on the pedals throughout the crank rotation. This
    is extremely difficult to achieve since force

    huh?? I dont think anybody is talking that level of precision.

    But that is what you imply when you demand having constant pedal speed.

  20. Jose Rizal said:
    Quoted message said:

    Eh? constant angular velocity means constant cadence. 1 rad/s = 9.55 rpm

    No, you can achieve constant cadence without having constant angular velocity within one
    revolution. Within one revolution, the crank angular velocity can (and in practice, does) vary,
    but as long as this variation in speed is consistent with each revolution, the cadence will

    Sounds like biopace gears to me. Otherwise you are talking about the bike rapidly accelerating and
    decelerating, and thats just silly.

    Quoted message said:

    stay the same. For example, the angular velocity may be at a peak when the cranks are horizontal
    with one leg pushing down and the other

    Well, theoretically and immeasurably tinily. Actually, the peak speed is later, when pedal power
    drops below friction power. But of what possible relevance are these microscopic speed
    oscillations??

    Quoted message said:

    But that is what you imply when you demand having constant pedal speed.

    No. I mean linear speed, not angular. It aint rocket science.

    --
    make nospam into oz to reply.

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