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Significant Accident

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Cycling Equipment
Published
17 September 2004
Last activity
24 September 2004
Original author
Arthur Shapiro
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42
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  1. Last night was my club's last weekday ride due to declining daylight hours.
    We normally have several separate rides, but everyone was happy to have just
    one ride and allegedly ride together for a flat, easy 14 miles (!) to sadly
    mark the end of summer.

    Of course, the fast folks steadily pulled ahead, despite not really pushing
    hard, and I stayed back with the stragglers, being woried that I might have to
    push them if the pace got too slow and daylight started to fade.

    As we came around a corner, I could see a group of our riders stopped ahead,
    thanks to our distinctive yellow jerseys, along with several cars with
    flashers on. This was clearly not a regroup and not a good sign. We got
    there to see a rider down. He was barely conscious, and soon unconscious,
    with the heavy, labored breathing that I saw a year or two ago after a
    high-speed head on collision between two cyclists.

    It wasn't one of our riders; it turned out to be the former president of a
    "rival" area club who just coincidentally had overtaken, or been overtaken by,
    our riders. He was apparently standing on it, according to several reports,
    and snapped something, and went down hard and heavy on his fortunately
    helmeted head, right in the middle of our small group. I noticed only slight
    road rash on one leg. It took over five minutes to get the paramedics and
    fire trucks, despite the station being, I believe, only a few hundred feet
    down the intersecting street right where we were. As they were loading the
    guy into an ambulance, I insisted my riders take off with me, fast, as roughly
    a fifteen minute delay meant night riding was a real possibility. Two riders
    with lights, both who knew the victim, stayed behind and were trying to find
    a phone number to call his family. We got back in twilight without incident,
    although I had to push one lady, with whom I often ride; she was *quite*
    shaken by seeing the incident occur directly in front of her.

    I am really embarrassed to say that I didn't note the make/model of equipment,
    although this was clearly a non-trivial bicycle. The bottom bracket spindle
    had snapped at the right crank arm, with the "stub" still in the arm. It
    wasn't a perfect smooth cleave. I'm not a metallurgist, and didn't really
    know what I might look for to assess the cause. Obviously it gave suddenly,
    under full pressure, causing the guy to unexpected lurch to the right side and
    go down really hard.

    I've heard of cranks breaking, normally Campy for some reason (probably the
    stronger riders ride Campy), but don't think I've encountered a fractured BB.
    As one who stands on it continuously for almost all hills, it's a matter of
    some concern even if this was a one-in-a-million failure.

    Art

  2. Arthur Shapiro said:

    I am really embarrassed to say that I didn't note the make/model of equipment,
    although this was clearly a non-trivial bicycle. The bottom bracket spindle
    had snapped at the right crank arm, with the "stub" still in the arm. It
    wasn't a perfect smooth cleave. I'm not a metallurgist, and didn't really
    know what I might look for to assess the cause. Obviously it gave suddenly,
    under full pressure, causing the guy to unexpected lurch to the right side and
    go down really hard.

    I wonder if it was titanium? Incidentally, the fracture would not
    necessarily be a "cleave". It would have looked like this if the
    failure was due to fatigue in torsion, as is most likely for a BB spindle:

    http://www.engr.sjsu.edu/WofMatE/images/shaft1.gif

    If you ever find out the make and model, do let us know.

  3. Arthur Shapiro said:

    This was clearly not a regroup and not a good sign. We got there to
    see a rider down. He was barely conscious, and soon unconscious,
    with the heavy, labored breathing that I saw a year or two ago after
    a high-speed head on collision between two cyclists.

    Quoted message said:

    I am really embarrassed to say that I didn't note the make/model of
    equipment, although this was clearly a non-trivial bicycle. The
    bottom bracket spindle had snapped at the right crank, with the
    "stub" still in the crank. It wasn't a perfect smooth cleave. I'm
    not a metallurgist, and didn't really know what I might look for to
    assess the cause. Obviously it failed suddenly, under pressure,
    causing the rider to lurch to the right and go down hard.

    It was most likely a fatigue failure or else it would have broken with
    the first few starts from a stand-still or on a short steep hill like
    an under- or overpass. That's why I believe you should find out what
    brand BB this was so at least we who read this newsgroup will have the
    benefit of knowing whose spindles are more failure prone.

    Quoted message said:

    I've heard of cranks breaking, normally Campy for some reason
    (probably the stronger riders ride Campy), but don't think I've
    encountered a fractured BB. As one who stands on it continuously
    for almost all hills, it's a matter of some concern even if this was
    a one-in-a-million failure.

    I don't believe so. I have heard reports of ISIS spindles failing at
    the root of the spline, probably from a sudden change in cross
    section. Attaching a crank to a spindle is not trivial as was
    mentioned in another thread. That is why Shimano has made the FC-7800
    design. That the right end failed is doubly disconcerting because the
    left end sustains greater loads of bending combined with torsion while
    the right side experiences either bending or torsion separately.

    Please report back what brand and model BB assembly this was.

    Jobst Brandt
    [email hidden]

  4. Quoted message said:

    ...
    I don't believe so. I have heard reports of ISIS spindles failing at
    the root of the spline, probably from a sudden change in cross
    section....

    Here is an example of what may be such a failure:
    <http://www.sheldonbrown.com/fsabb.html>.

    --
    Tom Sherman

  5. In article said:

    Please report back what brand and model BB assembly this was.

    I shall try and find out; it may take some time, especially if the gentleman
    was gravely injured.

    I recall that the crank arm I was holding had a sculpted section on the
    inside, and didn't seem to have any logo on it. I put the crank through one
    of the empty water bottle cage holders, in hopes that the firemen (who had
    agreed to take the bicycle) would not lose it. I never took the bike off the
    ground, but probably - it's easy to say in hindsight - would have noticed
    Campy STI upshifting buttons, even on the ground. And in the very back of my
    mind is still the impression that this was a splined BB, not a traditional
    tapered guy. But I dare not swear to that.

    The fracture, although not a smooth separation, was smoother than some of
    those pictures folks have posted. I was carrying a camera and really should
    have captured the specifics.

    Art
    Temporary usercode - to be deleted when spam starts. Use MyBrainHurts at this ISP to reach me

  6. I've had an immense case of brain fade - it was a left side fracture, not a
    drive side (sorry, Jobst). My first email to one of the two guys who
    stayed behind hit paydirt: it turns out that he took the crank arm and has it
    with him. He described it as "Campy for the Racing T", which is terminology
    unfamiliar to me.

    I've asked him for a digital photo ASAP, but I don't know if he has a camera.
    I'll post any decent picture, or otherwise ask him to bring it on one of the
    weekend rides and take a couple shots myself.

    Art
    Temporary usercode - to be deleted when spam starts. Use MyBrainHurts at this ISP to reach me

  7. [email hidden] (Arthur Shapiro) wrote in
    news:CEL2d.301218$Oi.259971@fed1read04:

    Quoted message said:

    with him. He described it as "Campy for the Racing T", which is
    terminology unfamiliar to me.

    That's a Campy Chorus racing triple crankarm. I'm sure
    Campy would like to have a look at it..

    ken

  8. OK, I have confirmation that it was a 175 mm. Campy Racing T.

    Still begging for photos, but all I get back is that the bike-side fracture
    is more spectacular than the crank, but he'll bring the crank to tomorrow's
    ride.

    The gentleman had a broken arm, broken rib(s), and broken shoulder at last
    report.

    Art
    Temporary usercode - to be deleted when spam starts. Use MyBrainHurts at this ISP to reach me

  9. Quoted message said:
    Arthur Shapiro said:

    This was clearly not a regroup and not a good sign. We got there to
    see a rider down. He was barely conscious, and soon unconscious,
    with the heavy, labored breathing that I saw a year or two ago after
    a high-speed head on collision between two cyclists.

    Quoted message said:

    I am really embarrassed to say that I didn't note the make/model of
    equipment, although this was clearly a non-trivial bicycle. The
    bottom bracket spindle had snapped at the right crank, with the
    "stub" still in the crank. It wasn't a perfect smooth cleave. I'm
    not a metallurgist, and didn't really know what I might look for to
    assess the cause. Obviously it failed suddenly, under pressure,
    causing the rider to lurch to the right and go down hard.

    It was most likely a fatigue failure or else it would have broken with
    the first few starts from a stand-still or on a short steep hill like
    an under- or overpass. That's why I believe you should find out what
    brand BB this was so at least we who read this newsgroup will have the
    benefit of knowing whose spindles are more failure prone.

    Quoted message said:

    I've heard of cranks breaking, normally Campy for some reason
    (probably the stronger riders ride Campy), but don't think I've
    encountered a fractured BB. As one who stands on it continuously
    for almost all hills, it's a matter of some concern even if this was
    a one-in-a-million failure.

    I don't believe so. I have heard reports of ISIS spindles failing at
    the root of the spline, probably from a sudden change in cross
    section. Attaching a crank to a spindle is not trivial as was
    mentioned in another thread. That is why Shimano has made the FC-7800
    design. That the right end failed is doubly disconcerting because the
    left end sustains greater loads of bending combined with torsion while
    the right side experiences either bending or torsion separately.

    Please report back what brand and model BB assembly this was.

    Yes, please do get more info.

    I'll place money that it was NOT the square-tapered steel piece that has been
    doing the job perfectly well for decades.

    Ron

  10. On Sat, 18 Sep 2004 02:04:04 GMT, [email hidden]

    (Arthur Shapiro) said:

    OK, I have confirmation that it was a 175 mm. Campy Racing T.

    Still begging for photos, but all I get back is that the bike-side fracture
    is more spectacular than the crank, but he'll bring the crank to tomorrow's
    ride.

    The gentleman had a broken arm, broken rib(s), and broken shoulder at last
    report.

    Art
    Temporary usercode - to be deleted when spam starts. Use MyBrainHurts at this ISP to reach me

    Dear Art,

    If hosting pictures of the broken part is a problem, feel
    free to email it to me at [email hidden], and I'll be
    glad to put it up--people seem quite interested.

    Carl Fogel

  11. Quoted message said:


    If hosting pictures of the broken part is a problem...

    Not a problem - I'm the club's webmaster. But I'll probably put it up on my
    personal site. At this point, the custodian is reluctant to bring the bike (a
    Merlin) and leave it in his truck during the ride. I've suggested removing
    the wheels so it will trivially fit in his cab. We'll see what shows up at
    the start tomorrow.

    Art

    Art
    Temporary usercode - to be deleted when spam starts. Use MyBrainHurts at this ISP to reach me

  12. Arthur Shapiro said:

    OK, I have confirmation that it was a 175 mm. Campy Racing T.

    Still begging for photos, but all I get back is that the bike-side fracture
    is more spectacular than the crank, but he'll bring the crank to tomorrow's
    ride.

    The gentleman had a broken arm, broken rib(s), and broken shoulder at last
    report.

    Art
    Temporary usercode - to be deleted when spam starts. Use MyBrainHurts at this ISP to reach me

    Ouch! thats gotta hurt. At least these are not life threatening
    injuries. I wish him a speedy recovery. I am certain that Campagnolo
    would like to know about this (As would Shimano if the BB had been
    theirs). All the best.

    Stan Cox

  13. I've posted eight photos of the crank on a private page of the club's web
    site:

    http://www.ocrebels.com/CrankFailure.htm

    With apologies to those with dialup connections: while I always post club
    photos at 600x480, these eight linked photos are at 1600x1200, to enable a
    closer view. I thought I'd pulled the out-of-focus ones, but shot #1
    accidentally got left in, and I don't feel like regenerating the sequence.

    Art

    Art
    Temporary usercode - to be deleted when spam starts. Use MyBrainHurts at this ISP to reach me

  14. Arthur Shapiro said:

    I've posted eight photos of the crank on a private page of the club's web
    site:

    http://www.ocrebels.com/CrankFailure.htm

    With apologies to those with dialup connections: while I always post club
    photos at 600x480, these eight linked photos are at 1600x1200, to enable a
    closer view. I thought I'd pulled the out-of-focus ones, but shot #1
    accidentally got left in, and I don't feel like regenerating the sequence.

    Art

    Art
    Temporary usercode - to be deleted when spam starts. Use MyBrainHurts at this ISP to reach me

    Looks like a crack is visible in #8 at the bottom of the photo.

  15. Arthur Shapiro said:

    I've posted eight photos of the crank on a private page of the
    club's web site:

    http://www.ocrebels.com/CrankFailure.htm

    Quoted message said:

    With apologies to those with dialup connections: while I always post
    club photos at 600x480, these eight linked photos are at 1600x1200,
    to enable a closer view. I thought I'd pulled the out-of-focus
    ones, but shot #1 accidentally got left in, and I don't feel like
    regenerating the sequence.

    This is an interesting appearing failure in that it seems to be a
    bending failure and initially not one of torque. I say that on the
    basis of picture #7 in which crack inception occurs with the crank
    forward under pedal load. The crack started at the "top". The rough
    (crystalline) and rusty surface shows that the crack developed
    gradually and even rusted before advancing far enough to cause a
    torsional failure. Torsion acts on a helical shear plane at about 45
    degrees to the spindle axis. That is why the failure surface is a
    helical ramp.

    How many miles did this unit survive?

    That we have a picture of the stub still in the crank is good, because
    that way the crack inception location is discernable. However, a nice
    angle shot of the larger part of the spindle (grease and dirt removed)
    would make the "spiral" fracture more obvious. I have had such a
    failure on a Campagnolo Record spindle but it occurred inside the
    crank where the greatest torque and bending is applied... about 2mm
    inside the press fit.

    Since then I have used Shimano BB's and spindles, even with my
    Campagnolo cranks. That doesn't mean it can't occur again but it
    hasn't for a long time.

    Jobst Brandt
    [email hidden]

  16. <Since then I have used Shimano BB's and spindles, even with my
    Campagnolo cranks. That doesn't mean it can't occur again but it
    hasn't for a long time.>

    I was under the impression that Shimano and Campagnolo tapers were
    significantly different and not compatable.

    Eric

  17. An anonymous poster quoted somebody without attribution:

    Quoted message said:

    <Since then I have used Shimano BB's and spindles, even with my
    Campagnolo cranks. That doesn't mean it can't occur again but it
    hasn't for a long time.>

    and responded:

    Quoted message said:

    I was under the impression that Shimano and Campagnolo tapers were
    significantly different and not compatable.

    You're not alone, many people are under this impression.

    In my experience, however, it is almost never a problem in practice, if
    you make allowance for the desired chainline.

    My own personal fleet includes bikes with Campagnolo/Shimano
    crank/bottom bracket mixes in both directions, and none of them has
    given me a lick of trouble on that account.

    Sheldon "Works For Me" Brown
    +---------------------------------------------------+
    | In theory, there's no difference between theory |
    | and practice; but, in practice, there is. |
    +---------------------------------------------------+,
    Harris Cyclery, West Newton, Massachusetts
    Phone 617-244-9772 FAX 617-244-1041
    http://harriscyclery.com
    Hard-to-find parts shipped Worldwide
    http://captainbike.com http://sheldonbrown.com

  18. Sheldon Brown said:

    An anonymous poster quoted somebody without attribution:

    Quoted message said:

    <Since then I have used Shimano BB's and spindles, even with my
    Campagnolo cranks. That doesn't mean it can't occur again but it
    hasn't for a long time.>

    and responded:

    Quoted message said:

    I was under the impression that Shimano and Campagnolo tapers were
    significantly different and not compatable.

    You're not alone, many people are under this impression.

    In my experience, however, it is almost never a problem in practice, if
    you make allowance for the desired chainline.

    Is it possible to make chainline predictions just from the length of
    the spindle? Or are their differences in the diameter of the tapered
    section of the axle between the two brands. That is, will a
    Campagonolo and Shimano spindle of, say 107mm both result in the same
    chainline?

    JT

    ****************************
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  19. Arthur Shapiro said:

    I've posted eight photos of the crank on a private page of the club's web
    site:

    http://www.ocrebels.com/CrankFailure.htm

    Hmm. Note what looks like a flaw in the metal at the 9 o'clock
    position, surrounded by corrosion:

    http://www.ocrebels.com/images/failure/pic7.htm

    It looks to my untrained eye that this could have been the original
    source of the crack. I'm also curious about the shiny section, from
    about the 1 o'clock position to the 7 o'clock position. The polished
    surface suggests that the fracture was there quite a while, and the
    relative movement of the pieces did the polishing.

    If there are any materials people here, could they comment?
    --
    terry morse Palo Alto, CA http://bike.terrymorse.com/

  20. Arthur Shapiro said:

    I've posted eight photos of the crank on a private page of the club's web
    site:

    http://www.ocrebels.com/CrankFailure.htm

    With apologies to those with dialup connections: while I always post club
    photos at 600x480, these eight linked photos are at 1600x1200, to enable a
    closer view. I thought I'd pulled the out-of-focus ones, but shot #1
    accidentally got left in, and I don't feel like regenerating the sequence.

    Art

    Art
    Temporary usercode - to be deleted when spam starts. Use MyBrainHurts at this ISP to reach me


    looks like there was a crack (lower left apx 7pm) which lead to failure

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