Lightweight Challenge 700 -> 721.3gr!

Discuss light weight issues concerning road bikes & parts.
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strobbekoen
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by strobbekoen

Dude, you keep picking on people for not being scientific or showing you the numbers.. I have not seen you posting anything scientific with numbers ever relating the products you seem so eager to defend.

alienator
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by alienator

strobbekoen wrote:@alienator:
That is not what Adrien said. He did not say "stiff is always better" as an absolute. It is the same argument you and I had in a previous post where you insisted on the argument as if i said "stiff is always better" which i didn't. He didn't either.


I don't remember any such argument with you, but that's beside the point.

Adrien said:
about the stiffness, yes it is very important, almost at any place of the bike. Mavic performed serious tests with stiff and flexy components, same super powerful track guy, same position, etc... the stiffness of the components allow the rider to exploit his full potential while reaching the maximal hearth rate. With less stiff components, the rider can't exploit fully his potential. You can contact Mavic if you want to know more. They perform thousands interesting tests.

Note that it is specifically implied that less stiff components prevent a rider from exploiting his full potential. That sure sounds like a blanket statement from Mavic. And it certainly says that stiff is always better, else you won't exploit the potential you could.

alienator
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by alienator

strobbekoen wrote:Dude, you keep picking on people for not being scientific or showing you the numbers.. I have not seen you posting anything scientific with numbers ever relating the products you seem so eager to defend.


See, I'm not defending a product, Dude. I am defending a tenet of good engineering which is that you design a product with the characteristics it needs to perform to its design specs. The idea that stiffness must be of a certain quality no matter the wheel design flies in the face of good engineering. It's simple, dude.

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strobbekoen
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by strobbekoen

Anyone with common sense would agree with Adrien on this. Show me your numbers to prove the contrary. Why would your questioning one thesis be more valid than the thesis ? I have not seen you posting any objective data. All you do is question other people's arguments!

chrism
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by chrism

PezTech wrote:What "Big advantage" do Lightweights "throw away" with regard to tensioned spokes?

That by pre-stressing a tension member it can effectively support "compression". Therefore as I keep saying, not only does the spoke losing tension contribute to the lateral stiffness, but also the spokes at the bottom of the wheel contribute to supporting the rim against forces from the ground. Is a common misconception that wheels hang from the top spokes - that is effectively how LWs work, but a traditionally spoked wheel with pre-stressed spokes doesn't - it stands on the bottom spokes.

See http://www.sheldonbrown.com/rinard/wheel/index.htm for data on how spokes becoming totally slack (as is the case from the start if there is no spoke tension) affects wheel stiffness.

The talk on here is all about how carbon has some magical properties that means you can build your wheels differently. Quick reality check here - it has no magical properties, just a better specific stiffness than steel. This means that for a given stiffness a tension spoke can be lighter, but that doesn't change the way the spoke works. There is nothing magical about the way these wheels work - you could build something much the same out of steel/alu if you wanted, but it would obviously be heavier. Spoke pre-tension would benefit them in terms of stiffness in just the same way as for a conventional wheel with no weight penalty (arguably you could then make them lighter for the same performance).
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Adrien
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by Adrien

Yes I meant stiff components are required to exploit fully the rider potential.
Keep in mind that a light and weak rider will not need as stiff wheels as a heavy powerful guy. The tests were performed with a 20kg lateral load.

Yes Alienator, you really seem like defending Lew from your posts. Take it easy and be fair.
Lew, Mavic or Lightweight: from all of them I would prefer to have a Lew 2008 wheelset, even though they were tested as the most flexy! ;) (just to let you see I don't defend any of the two other!)

alienator
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by alienator

Adrien wrote:Yes Alienator, you really seem like defending Lew from your posts. Take it easy and be fair.


Well, that's the beauty of reading text on a screen: your free to assume things to be a certain way even if there not that way.

alienator
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by alienator

strobbekoen wrote:Anyone with common sense would agree with Adrien on this. Show me your numbers to prove the contrary. Why would your questioning one thesis be more valid than the thesis ? I have not seen you posting any objective data. All you do is question other people's arguments!


Well, then there you go. Take your common sense and run with it, Dude. Before you run off though, Dude, by the definition of Scientific Method, theses are to be questioned, dude. That's what it's all about.

What data am I supposed to provide, especially since I'm just supporting sound engineering principles? Dude, pull up some data if you want to support your pet thesis, but remember it's the one with the thesis that is required to provide the data.

Doesn't it suck when that whole science and scientific method thing get in the way, dude?

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strobbekoen
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by strobbekoen

Be a little bit more critical of yourself before you tell people of using scientific verbage. You are not the only person granted to this privilege. To be honest i am getting tired of you picking on people while not providing any substantial arguments yourself.

Doesn't it suck when that whole science and scientific method thing get in the way, dude?

I guess this tells the story. You are obviously the only one capable of grasping science and scientific methods.

What data am I supposed to provide, especially since I'm just supporting sound engineering principles? Dude, pull up some data if you want to support your pet thesis, but remember it's the one with the thesis that is required to provide the data.

What thesis ? What engineering principles ? You never provided anything constructive. You just enjoy picking out whatever it is that you think is not scientific. The best sailors stand ashore don't they ?
Last edited by strobbekoen on Mon Oct 22, 2007 8:46 pm, edited 2 times in total.

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currieinahurry
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by currieinahurry

and whats wrong with the word dude its one of my favourites?
tikka
:)

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Adrien
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by Adrien

alienator wrote:
Adrien wrote:Yes Alienator, you really seem like defending Lew from your posts. Take it easy and be fair.


Well, that's the beauty of reading text on a screen: your free to assume things to be a certain way even if there not that way.


I wrote "you seem".

Now I think it's better to go back on topic. Will Lew propose a lighter wheelset to reply to the lightest wheelset of the world?

chrism
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by chrism

alienator wrote:What data am I supposed to provide, especially since I'm just supporting sound engineering principles?

Since you don't seem to understand how a normal tension spoked wheel works and why the parts of a LW / Lew being carbon don't make any difference to the engineering behind it, then I'd suggest you're not actually, dude. Since I'm basing my argument on well researched principles, I'd suggest it's you who needs to come up with some proper arguments to support your theory if you think carbon spoked wheels work differently, dude.

You'll note that I agree with you, tikka, dude :D
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Mario Jr.
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by Mario Jr.

As far as I know, carbon has it´s strengths in elongation, not compression, where it´s rather weak. That makes it different from metals. Hence the different construction methods and designs.

chrism
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by chrism

Carbon does just fine in compression provided it is supported in an epoxy matrix. Otherwise carbon bike frames (where the top tube, seatstays and seattube are in compression) wouldn't work. Then again metal spokes don't do so well in compression either due to buckling!
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stilldt
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by stilldt

I don't really want to get this thread more heated, but I must ask this since it's not yet been answered. alienator, DO YOU OR DO YOU NOT WORK FOR LEW? How about an honest answer?

alienator wrote: A well designed product is as stiff as it needs to be, as strong as it needs to be to meet it's performance targets. It does not have to meet some generic "wheel's must be built like this" ideal.


That would be fine if every company would design a custom wheel for every customer. If not they must be built to some generic standard as they need to work for almost any rider that gets on them. Certainly my 208lbs needs a stiffer wheel than someone weighing half as much.

strobbekoen wrote:Dude, you keep picking on people for not being scientific or showing you the numbers.. I have not seen you posting anything scientific with numbers ever relating the products you seem so eager to defend.


But he did post something scientific relating to products.
alienator wrote:I know some have raised questions about the design, and some have questioned whether they've done any CFD and/or wind-tunnel time. LEW claims that the spoke profiles coupled with the rim profile is more aero than a 100mm rim with metal spokes (I'm assuming bladed spokes). While I may be somewhat gullible, I find it hard to believe that they'd make such a claim without having done the tests to back it up. And those tests would have to be wind tunnel tests. I think CFD testing for a spinning wheel, especially with a lot o' spokes, would be a nightmare.


It seems quite convenient to require others to post links to published data yet not require it for yourself or your company.
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