Omg, ain't that the truth! Some things have come out of that country that has no right existing in this world.CAMPYBOB said:
Simple Comparison Of Campy Record To Super Record?
- Thread starter Bob Ross
- Start date
This is what happens nowadays when you go for the lightest stuff you can find, it breaks because they use thinner metal to reduce weight, or they use lightweight metal in areas that the metal they're using wasn't design to handle that kind of load. Back in olden days when a person bought high end components it also meant it would hold up longer, not in todays world; combine that with the marketing approach that if they break it they will buy it mentality of modern corporations of any industry and you have this sort of problem pictured above. Unless you're ultra wealthy, or are racing with sponsors to pay for this junk, there is no need for someone to be buying this sort of garbage. Personally I think that if your ultra wealthy and don't care about stuff breaking because it uber light maybe you should care about the possible injuries that could be sustained when something breaks, the above crank breakage could have resulted in a very serious injury to the rider.Volnix said:So now you have to count teeth for the bottom bracket too huh?
So you got a 12T Crank spider which will be "upgraded" to 13T next year (Why? What do you mean why? Because it's... faster! Go and buy it now before someone sees you.)
Or you wanna wait until they change the cups for Over Size Bottom Bracket II ( the extra slippy version with balls made of Satanium, which dont fit to the medium slippy one which accepts the torque-ier crank).
This is f@ckin sh^t... Thousands of companies making bicycles. Only 3 f@ckin companies making transmission parts...
Agree in general that ultralight components are stupid. But it's what us customers tend to demand over durability. After all, weight, unlike strength and durability, is easily measured, and lightweight is automatically worth more to many buyers. As if shaving off metal, making something thinner, makes it a "better part". But hey, we're all racers in our fantasy minds, and saving that last pound in bike weight could make all the difference on the next weekend club ride.....even if we're 25 lbs overweight ourselves (like me currently).
Concerning that failure picture, my first thought is that the failure is likely due to over-torque of the fixing bolt. If the failure was caused by simply excessive force on the crankarm, or poor metallurgy, the thin section spindle would fail, but not continue through the hub area around the bolt. IE, my theory is that the crack started there in the hub and progressed out to the end of the spindle.
Believe bolt over-torqueing is likely to occur with this hirth joint design because if the crank ever starts clicking, the first response would be to go in and tighten the bolt "real good". Getting back to your theme, this ultralight stuff has to be installed and maintained (and used) carefully to maintain it's integrity...why risk it to save miniscule weight?
Concerning that failure picture, my first thought is that the failure is likely due to over-torque of the fixing bolt. If the failure was caused by simply excessive force on the crankarm, or poor metallurgy, the thin section spindle would fail, but not continue through the hub area around the bolt. IE, my theory is that the crack started there in the hub and progressed out to the end of the spindle.
Believe bolt over-torqueing is likely to occur with this hirth joint design because if the crank ever starts clicking, the first response would be to go in and tighten the bolt "real good". Getting back to your theme, this ultralight stuff has to be installed and maintained (and used) carefully to maintain it's integrity...why risk it to save miniscule weight?
Froze said:
Yep... But then again in the old days they would go way far in terms of durability sometimes. Have you seen these 70's bicycles which instead of brake cables have articulated axles! to engage the brake?
I also get a feeling that they have run out of ideas... They just don't know what to do anymore to provide the market with something "new and improved" so they just go like: "-What are we gonna do this year? -Dunno man, let's just move the fixing point of the crank axle to the middle of the axle or something and whip a stiffness graph or something".
dhk2 said:
I am not sure where the weakest part of a rotating axle is (like which part gets the most torque and needs "thickening"). I suspect that it's either the middle, or the ends or both.
In frames for example it's the ends of each tube so the "butting" involves leaving the centre thinner and then reinforce the ends for added strength and better welding.
I even tried to find an FEM model illustrating the forces of the axle on a bicycle crankset and found nothing...
But... here's a bicycle crank axle FEM model (for f@ck knows what loads ofcourse) that I just "fished" from googlez...
You would think that it would make sense to add some thickness in the middle and the side. And you would also think that adding a fixing bolt in the middle would provide such thickness... But I kinda suspect that the result of the current design would be the threads of the middle bolt getting shaved off...
This is what I suspect that happened in the above crank. The forces on the non-homogenous system applied some more "concentrated" forces to parts of the axle near the fixing bolt which eventually shredded the axle. In this case the right part of it.
Really, there are somethings in cycling today that -simply don't make sense-.
Are hollow axles stronger in rotating forces? I'm not sure... I know that circular hollow sections are stronger in bending forces then their equivalent solid circular beams but...
Oh yeah, I forgot... It's lighter!
From http://www.extralite.com/ bike parts
LOL, this was funny but correct, I think engineers do the same thing with cars too, gee where should we put the spare? I know under a rear seat and carpet so it takes 15 minutes to try to figure out how to get the seat up and out and then get the carpet/floor out of the way, and have it engaged by a seemingly endless length bolt so that takes 5 minutes just to spin that off, then locate the jack somewhere else where no one would ever suspect to find it like under the front seat or inside the engine compartment, why locate it with the spare? Now spend another 30 minutes trying to get it all back together again.Volnix said:Yep... But then again in the old days they would go way far in terms of durability sometimes. Have you seen these 70's bicycles which instead of brake cables have articulated axles! to engage the brake?
I also get a feeling that they have run out of ideas... They just don't know what to do anymore to provide the market with something "new and improved" so they just go like: "-What are we gonna do this year? -Dunno man, let's just move the fixing point of the crank axle to the middle of the axle or something and whip a stiffness graph or something".
Anyway, back to bike components, in 1984 I bought Suntour Superbe components for a Trek 660 frame and fork I bought, 160,000 plus miles later it still runs fine. Racing back then wasn't about buying borderline durability to get the lightest equipment and hope it holds up through one race, in fact it was almost a durability race! You wanted your bike to hold up so you knew you would have a chance to win, and in the non pro ranks as I was, a lot of riders couldn't afford to be replacing their equipment year after year, we needed that stuff to last the entire racing career! (barring any crashes of course) Granted there were a lot of guys racing that had wealthy parents and they bought whatever the newest greatest thing that came along every year, those guys also didn't have to work like I did and others, so they spent their days just riding and mom and dad supported them...part of me says that would have been cool, maybe if I had that going on I could have actually won more races, but another part me says not so cool because it wouldn't have taught me about being independent.
Today, in the de Round de Vlaaandaaarrrennn we found out what shitmaNO is good for.
The shimaNo 'Help Me I'm In Neutral Support' Car knocked down Jesse Sergent of TREK (Duh! They use shitmaNO stuff!). The blast was worthy of a Hoogerland pop into the barbed wire. Thankfully Sergent suffered 'only a broken collarbone.
Later, trying to start a new tradition in cycle racing, the shitmaNO 'Help Me My Brain Is in Neutral' Service Car blasted into the rear of the FDJ team car as it was slowing to service one of its riders.
The resulting impact blew the bumper cover off and that cover smashed into the FDJ rider, taking him down.
Who needs service and parts from a company like that?!?!
The shimaNo 'Help Me I'm In Neutral Support' Car knocked down Jesse Sergent of TREK (Duh! They use shitmaNO stuff!). The blast was worthy of a Hoogerland pop into the barbed wire. Thankfully Sergent suffered 'only a broken collarbone.
Later, trying to start a new tradition in cycle racing, the shitmaNO 'Help Me My Brain Is in Neutral' Service Car blasted into the rear of the FDJ team car as it was slowing to service one of its riders.
The resulting impact blew the bumper cover off and that cover smashed into the FDJ rider, taking him down.
Who needs service and parts from a company like that?!?!
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