Rotor 3D+ broken crank

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mythical
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by mythical

Oh right, I did inadvertently write Nm. It seems my dyslexia is playing up. Apologies, Qman. :beerchug:

And, highdraw, you still don't seem to manage to spell ‘mythical’ correctly. Willful blindness, eh? :wink:
“I always find it amazing that a material can actually sell a product when it’s really the engineering that creates and dictates how well that material will behave or perform.” — Chuck Teixeira

highdraw

by highdraw

Sorry about that. I think I was distracted by what you wrote about weight being irrelevant to strength.
I think you may revolutionize the bike industry with your repudiation of physics. Ground breaking.
But have to ask, where is that 5 lb bicycle and 500g wheelset?...lol. Hey, maybe you will come up with a uber strong 1 lb bike and 50g wheelset?...that is when pigs learn to fly.

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mythical
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by mythical

Here is something that comes close: http://velonews.competitor.com/2010/09/interbike/interbike-2010-tech-gallery-%E2%80%93-a-45000-six-pound-carbon-road-bike-assembled-by-fairwheel-bikes_142776

Image

Just convert to singlespeed and it should weigh about 5 lbs with a 500g wheelset.

highdraw wrote:Hey, maybe you will come up with a uber strong 1 lb bike and 50g wheelset?...that is when pigs learn to fly.
Or simply ride that bike on the moon, where it would weigh about 460 grams :D
“I always find it amazing that a material can actually sell a product when it’s really the engineering that creates and dictates how well that material will behave or perform.” — Chuck Teixeira

highdraw

by highdraw

How do you think that bike would hold up to Greipel's power? ;-)
Snap, crackle, pop.

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prendrefeu
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by prendrefeu

highdraw wrote:How do you think that bike would hold up to Greipel's power? ;-)
Snap, crackle, pop.


Again, you appear to be on the wrong forum. :noidea:
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rasmussloth
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by rasmussloth

Looking forward to hearing Rotor's answer to this.

highdraw

by highdraw

prendrefeu wrote:
highdraw wrote:How do you think that bike would hold up to Greipel's power? ;-)
Snap, crackle, pop.


Again, you appear to be on the wrong forum. :noidea:

reported

highdraw

by highdraw

rasmussloth wrote:Looking forward to hearing Rotor's answer to this.

Perhaps unlikely Rotor would provide a substantive response because it would be an indictment of the integrity of their product. I presume they would replace the crank however and in the OP's case, not sure I would ride it, or if I did, I would take it out of service after say the 1 year mark to preclude a similar repetition of fatigue failure. I find Qman's comments to be spot on. In production validation, often manufacturers will not simply test to the specification bogie and call it good. This is an accident in waiting as many specifications are limited in terms of identifying all potential failure modes and as explained the specification doesn't always identify all and sometimes doesn't address many possible failure modes or loading scenarios that can induce failure. For this reason, separate tests are generally concocted by the manufacturer to identify these weak links and in fact sometimes based upon feedback of failures in the field. Field failures in fact on safety critical assemblies like a crankset can even precipitate on going production lot acceptance testing whereby parts are taken off the assembly line in real time and tested to failure to determine their robustness. Manufacturing variation as it turns out is a big determinant of how robust a given product is in the field over time. Testing to a bogie based upon a single load path to number of cycles for example many times will not expose how a crank is particularly loaded and perhaps true in the OP's instance for example. But production sampling to failure does expose the margin of material and production variation if multiple load paths are tested. This has a cost for example but so does parts failing in the field and hurting people in terms of liability. So depends on the manufacturer and their vigilance to ensure the public is safe by testing their product comprehensively which again as Qman pointed out is many times well above a given acceptance standard to ensure there are no precipitous failures. As it turns out modeling tests to encompass material and manufacturing variation to insure there are negligible failures in the field is one of the biggest challenges for any manufacturer of safety critical products.

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Mario Jr.
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by Mario Jr.

Again, having sold a lot of 3D+ cranks since 2009 without any broken ones, I would say that they are as safe as pretty much anything else out there.
Fact is, if there was a general problem with the 3D+ cranks, we would have heard about it. But there's not. I bet this particular crank had a flaw in the material or in the production. I mean, making a conclusion based on one (1) broken crank is rediculous and not possible. If you google "broken xxx crank", you can find any sort of crank that's broken. Does that mean that they are inherently bad products? Of course not. Some has a bad record of pedal threads coming loose, like the older FSA ones, but apart from that, a few broken Dura Ace cranks does not make those dangerous to ride. The same with the Rotor cranks.

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prendrefeu
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by prendrefeu

highdraw wrote:
prendrefeu wrote:
highdraw wrote:How do you think that bike would hold up to Greipel's power? ;-)
Snap, crackle, pop.


Again, you appear to be on the wrong forum. :noidea:

reported


For what, exactly?

That's not an insult, it's just an opinion: you may be on the wrong forum. :noidea:
This forum is oriented towards low weight x high strength. In this and other threads you throw off remarks like low weight/high strength is not feasible... yet it gets shown, in real world results, that it does exist. In a another thread you throw off remarks about cost and operating a business - while cost may be a factor for many in affording high quality parts, many others can also afford those parts and are willing to purchase at that price and businesses do exist just fine offering an exceptionally tight manufacturing tolerance at a high cost.

It's like you're not paying attention to, not listening to, nor respecting the crowd you're trying to give your opinion to.

And yes, that bike would hold up to Greipel's power just fine. Would it hold up to his mass, however? It depends on the components which have weight limits (such as the saddle).
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Butcher
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by Butcher

Well said.

goodboyr
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by goodboyr

The tribe has spoken..........

highdraw

by highdraw

prendrefeu wrote:
highdraw wrote:
prendrefeu wrote:
highdraw wrote:How do you think that bike would hold up to Greipel's power? ;-)
Snap, crackle, pop.


Again, you appear to be on the wrong forum. :noidea:

reported


For what, exactly?

That's not an insult, it's just an opinion: you may be on the wrong forum. :noidea:
This forum is oriented towards low weight x high strength. In this and other threads you throw off remarks like low weight/high strength is not feasible... yet it gets shown, in real world results, that it does exist. In a another thread you throw off remarks about cost and operating a business - while cost may be a factor for many in affording high quality parts, many others can also afford those parts and are willing to purchase at that price and businesses do exist just fine offering an exceptionally tight manufacturing tolerance at a high cost.

It's like you're not paying attention to, not listening to, nor respecting the crowd you're trying to give your opinion to.

And yes, that bike would hold up to Greipel's power just fine. Would it hold up to his mass, however? It depends on the components which have weight limits (such as the saddle).

Let me make a final comment. What you wrote was insulting. What is particularly insulting is the fact I made my living designing this stuff and nobody here understands the relationships better than me.
Honestly, it doesn't seem like it in spite of my effort, but I find the dissension on this forum repugnant.
A stain on a wonderful sport where ideas should be able to be debated and even disagreement accepted without rancor or personal attacks.
So in that sense, you are absolutely right, I am on the wrong forum.
I have had enough and good bye. :beerchug:

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ultimobici
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by ultimobici

Seems a little high-strung..... :roll:

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florens
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by florens

Broke mine too. Called Rotor Spain and I think it was the fastest swap ever. In 10 days a new crank arrived with no questions asked about age, guarantee or whatsoever.

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