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  1. #1
    JLSF20
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    My Hollowgram Has Broken

    Hi everybody,

    Firstly sorry for my poor english. This is my first participation here.

    I had a big problem with my crankset Hollowgram 29x42T of my Rush Carbon. This weekend I was riding my bike, goind donw the hill after a uphill training, so suddenly my hollowgram broked and I felt down on the trail.

    I've been seeing one thread here before where a conrad said that his crankset has bent...so mine not bend before..it has broked before any bent. I've trying some garantee with Cannondale group. I thing is following some pictures here.

    Thanks
    Attached Thumbnails Attached Thumbnails My Hollowgram Has Broken-pe-de-vela-jorge10012008245.jpg  

    My Hollowgram Has Broken-pe-de-vela-jorge10012008245-1-.jpg  

    My Hollowgram Has Broken-pe-de-vela-jorge10012008245-2-.jpg  


  2. #2
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    i was just riding along and...

  3. #3
    Can't stop the Prophet
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    Was your bike on a car rack when this happened? Don't mean to sound skeptical but...........................hmm. I don't see how aluminum can tear away from itself like play doh.

  4. #4
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    No surprise...

    Quote Originally Posted by nathanbal
    i was just riding along and...
    That's how fatigue works. It's caused by accumulated damage over many thousands or millions of cycles, not a single overload cycle. So, the final failure can occur during normal use.

    Higher-than-normal loading can lead to fatigue crack initiation, but that would have been many weeks or months earlier.
    Last edited by steadite; 03-15-2010 at 08:34 AM.
    whatever...

  5. #5
    JLSF20
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    Quote Originally Posted by brows141
    Was your bike on a car rack when this happened? Don't mean to sound skeptical but...........................hmm. I don't see how aluminum can tear away from itself like play doh.
    No, it wasn't on a car rack. I was hiding down on trail after a long hill, and it happened suddenly. And about fatigue, I don't remember I hit it many time this crankset on the flor or rocks, etc.

    If you look the picture carefully, you'll see that crankset broked on the side of pedal when I was pushing the pedal not on the moment that my leg is streched in toward to the floor or some obstacles. That's why I guess it was a weld failure .

  6. #6
    Can't stop the Prophet
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    Weld?

  7. #7
    JLSF20
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    look at the first picture and you'll see how the weld of the aluminium seems to be tearing.

  8. #8
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    It's not a weld but a bond... But, since the end broke and wanted to seperate itself from the rest, the bonding coming apart is not surprising and is not what we should be concerned about IMO.

    Kind of odd that these cranksets have been one of the most durable and strong for years and recently, one breaks and one bends.
    Last edited by Dan Gerous; 03-15-2010 at 09:37 AM.

    DAN.GEROUS.NET : MOUNTAIN BIKING : CYCLOCROSS : ROAD :

  9. #9
    FIRENZE rulez !!
    Reputation: eliflap's Avatar
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    thanks for posting a pic of inside the arm




    ( just for joking... a tear out of my eye for your crank )

  10. #10
    Music & Bikes
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    up on the the bike , applying a pressure on the pedal , isn't the structure supposed to bend the other way ? (toward the exterior)

    I don't understand how it could possibly bend this way.....


    How have you fell ?
    "There is a big difference between kneeling down and bending over" -FZ

  11. #11
    JLSF20
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    I fell while riding and my foot went right into the vacuum touching on the floor and I was thrown in front of the bike.

  12. #12
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    If you apply pressure to the pedal it wants to go down at the cleat end, so it would tear inwards, as in the photo.

    An impact would either tear the other way, or just bounce the bike off. The only impact that would tear inwards is if the crank was pointed towards the rear wheel. In that position the force would be applied too far behind the CoG to not just deflect the bike.

    This looks legit, but i doubt the cause is too much torque. It must have been pre-fatigued. Cannondale could determine the cause pretty quickly if you sent it in, with a bit of x-raying and UV.

  13. #13
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    Quote Originally Posted by Cubits
    If you apply pressure to the pedal it wants to go down at the cleat end, so it would tear inwards, as in the photo.

    An impact would either tear the other way, or just bounce the bike off. The only impact that would tear inwards is if the crank was pointed towards the rear wheel. In that position the force would be applied too far behind the CoG to not just deflect the bike.

    This looks legit, but i doubt the cause is too much torque. It must have been pre-fatigued. Cannondale could determine the cause pretty quickly if you sent it in, with a bit of x-raying and UV.
    You're right , my bad.
    The upside position in the photo made me think the other way......
    "There is a big difference between kneeling down and bending over" -FZ

  14. #14
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    Same thing here. Fatigue fracture of the right crank two months ago (Rize Carbon 1). Cannondale replaced it on warranty. Last week same thing happened to the left crank. And now Cannondale does not want to replace.

    Lessons learned:
    • I will never again buy a Cannondale bike
    • the Hollowgram has horrible engineering, the fractures are preprogrammed. Two fractures on both cranks after two years of riding does not just happen by chance.
    • the breakages can be potentially very dangerous. The first one happened to me while going up a super-steep single trail. not at all funny!
    • Cannondale will hear from me. If they do not change their mind re. warranty, I intend to sue the hell out of them...

  15. #15
    JLSF20
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    I had my crank arm replaced 85 days after the problem occur. They sent it to me via LBS. I continue using it.

  16. #16
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    I have also seen a bent crank arm first hand and Cannondale replaced it, being that the bike was less than 1 year old (2009 rize carbon 1).

  17. #17
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    to me, all these reports mean that the crank is poorly designed and breaks frequently. If Cannondale were a honest and responsible company, they would issue a recall, and replace the crank with a better design to all Rize owners.

  18. #18
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    Quote Originally Posted by adriano View Post
    to me, all these reports mean that the crank is poorly designed and breaks frequently. If Cannondale were a honest and responsible company, they would issue a recall, and replace the crank with a better design to all Rize owners.
    Adriano, you are wrong. This is a very highend crank designed for and used by Protour racers and world cup athletes. It works very well in the intended application, however maybe bashing around into rocks on an all mountain bike is not the best application...but it for sure does not warrant a recall. If you want a more durable crank it will be heavier. Thats your trade-off.

  19. #19
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    Alias, thanks for your response. I do understand your viewpoint, and I accept that there are tradeoffs between lightweight components and their durability. I also wish to add that I utterly enjoyed riding my Rize - for as long as it didn't fall apart (less than 2 years).

    Yet I respectully dissent with your conclusion. In any bike, the crank are necessarily subjected to the highest forces which any bike part must sustain. World champions have been estimated to exert up to 22 kW on the cranks at peak power. That is way higher (probably by a factor of 100) than anything that I would ever be able to do to my bike.

    I have never fallen off my bike, I never rode it on a car rack, and I never mishandled it. Believe me, after spending 4K$ on a bike, you will be very careful with it! All I did was what a mountain bike is supposed to be good for, namely to ride mountains.

    If Cannondale engineers have decided to produce cranks that fail reproducibly and repeatedly after ca. 800 hrs., then they should tell customers that cranks are exceptionally lightweight yet are subject to fatigue and must be exchanged yearly. I would then be able to make an informed decision as to whether i can accept that tradeoff. However, I have never heard any such qualification from Cannondale - and that is, in my view, entirely unacceptable.

    I hope that you do not interpret the above as a critique to your post. The reason why I bought a Rize was that I was fascinated with the technology - and have loved riding it! Now I do feel let down - particularly by Cannondale's ununderstable refusal to provide warranty services. In fact, I feel tempted to post their asinine response here...

  20. #20
    Ridin' dirty!
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    [QUOTE=adriano;8265121] In fact, I feel tempted to post their asinine response here.../QUOTE]

    Do it, do it, do it, do it!
    Did I mention you should do this?
    "Common sense isn't always that common!"
    Custom Prophet and Custom Delta V

  21. #21
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    [QUOTE=cdalemaniac;8265167]
    Quote Originally Posted by adriano View Post
    In fact, I feel tempted to post their asinine response here.../QUOTE]

    Do it, do it, do it, do it!
    Did I mention you should do this?
    I am a peace-loving hobbyist rider, and an academic scientist by profession. It is not my intention to wage a war against Cannondale. But if left with no other option, I will expose their arguments and let the readers form their own opinions.

    There are many reports of broken Hollowgram cranks all over the internet, hence it may not be futile (and may help others as well) if I end up raising hell about this issue.

  22. #22
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    Its clear that the OP's Hologram Crank broke down the weld seem.

    Not shure where these Cranks are being made but most likely they are prone to failures at this certain stress point.

    I know Cannondale most surely has nifty stats on just how many they are Replacing and hwere the failure took place. But of course they will never releast that short of a lawsuit.

  23. #23
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    Even if there are a lot of broken crank reports floating out there you have to also consider how many were produced, and how many broke.
    Percentage of failure is really low I might assume.....
    There was a year when the coda magic 700 cranks failed as well (First outboard bearing bb crankset)......If I remember correctly the crank arms were made the same way the modern Hollograms are made by bonding 2 aluminum halves together with epoxy.
    The crankarm bolt's and pedal keep evrything clamped together on top of that.
    Maybe there's a similar failure this time around and cannondale need to figure something out.....
    Finding out the serial numbers of each broken crankarm might be a start to see if a certain batch is a affected......
    "Common sense isn't always that common!"
    Custom Prophet and Custom Delta V

  24. #24
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    I don't know how many reports of failure are floating around out there. But I do know the abuse I have dished to my hollowgram cranks over the years. A couple years back (during a race) I ran my crank arm into a rock at about 20mph, it stopped my bike, I flew over the bars and cartwheeled, landed with wind knocked out of me. I got up grabbed my bike and as I pedaled I could feel something was bent. I thought it was the crank arm or the pedal. Got home and took it all apart. It was the bb spindle that bent. Frame was fine, crank arms were fine. The only bummer was that the bb spindle that bent was a pretty rare 122mm one. Since this crash, the same crank arms have been bounced off if several rock not to mention the thousands of watts my legs have thrown at them. Anyway sorry for the long story, but there just aren't any stronger, light weight crank arms out there. Don't forget, if you don't like any parts on your bike you can change them out for something else.

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