sbeefyk2 wrote:
Just so we're all on the same page,.
You're never gonna make me believe that Nike was behind 9/11.
sbeefyk2 wrote:
Just so we're all on the same page,.
You're never gonna make me believe that Nike was behind 9/11.
What about a whole bunch of carbon fiber combined into something?
Bad Wigins wrote:
moot issue one way or the other. Springs won't make you run faster. Any "energy return" is merely pushing up on a heel that is already moving up on its own via the ordinary mechanics of running.
Try this, folks: while running, keep your heel on the ground all the way through takeoff. You can't. As your body moves forward, it pulls the heel forward and thus upward around the toe which is the last contact point with the ground. All forward acceleration is done by the body pushing itself forward from that toe.
If, somehow, "energy return" were able to add acceleration to this, it wouldn't be free - it would exert extra force on the body, and the body would have to exert extra equal and opposite force to counteract it. Any extra speed would still require the same extra effort it ordinarily would.
Think what happens when an elevator first starts ascending - it seems like gravity momentarily gets stronger. If you jump right then, you won't go any higher relative to the ground than when the elevator was at rest. Once it's moving, you might jump higher, but you still had to spend the extra energy counteracting the initial acceleration.
How is it possible for your grasp of physics to be so lacking?
Oh that's right you're 10 years old.
My bicycle has a carbon fiber frame and it works great!
sbeefyk2 wrote:
Just so we're all on the same page, carbon fiber cannot be a spring. It does not bend and propel forward. If carbon fiber bends, it will shatter. Especially very thin sheets such as those in a shoe. In a shoe it just gives support and stability to avoid losing energy that would be lost from a less structurally sound shoe.
what are your thoughts on the temperature of burning jet fuel and the melting point of steel beams?
It bends or doesn’t bend depending on how one arranges the layers of fibers.
Every seen someone take a slapper with a carbon fibre stick? Those sticks sure have some flex in 'em. I say we get rid of 'em. Bobby never used one and he'd still skate circles around the pansy euro players out there today.
Real men ride steel.... Or horses.... or steel horses.
exrunner wrote:
I’m loving all the wannabe materials scientists trying to get in on the Vaporfly discussion haha
Lol. Here is the other genius piping up.
Fyzics is Phun wrote:
Bad Wigins wrote:
moot issue one way or the other. Springs won't make you run faster. Any "energy return" is merely pushing up on a heel that is already moving up on its own via the ordinary mechanics of running.
Try this, folks: while running, keep your heel on the ground all the way through takeoff. You can't. As your body moves forward, it pulls the heel forward and thus upward around the toe which is the last contact point with the ground. All forward acceleration is done by the body pushing itself forward from that toe.
If, somehow, "energy return" were able to add acceleration to this, it wouldn't be free - it would exert extra force on the body, and the body would have to exert extra equal and opposite force to counteract it. Any extra speed would still require the same extra effort it ordinarily would.
Think what happens when an elevator first starts ascending - it seems like gravity momentarily gets stronger. If you jump right then, you won't go any higher relative to the ground than when the elevator was at rest. Once it's moving, you might jump higher, but you still had to spend the extra energy counteracting the initial acceleration.
How is it possible for your grasp of physics to be so lacking?
Oh that's right you're 10 years old.
Isn't he the 'flat earther'?
sbeefyk2 wrote:
Just so we're all on the same page, carbon fiber cannot be a spring. It does not bend and propel forward. If carbon fiber bends, it will shatter. Especially very thin sheets such as those in a shoe. In a shoe it just gives support and stability to avoid losing energy that would be lost from a less structurally sound shoe.
You're an idiot. Typical PC fanboy, just make a statement, toss a lie out there like it's the truth. lol
I don't know if carbon fiber really bends or not but know it's not the main reason why the % is such a fast shoe. It's fast because Nike manage to make a very light shoe with great cushion that defiently saves your legs in the later stages of a race. Before the 4% you either had to sacrifice weight or cushion. Now you can have both. This especially helps the recreational runners that were doing longer races in the Pegasus, adrenalines, 2100s and etc.
I actually think the first Hoka Clifton has a simalar feel out of the box, but the cushion lost it's responsiveness only after about 40 or 50 miles.
sbeefyk2. wrote:
Fart Garfunkel wrote:
Do you know what "bend" means?
Yeah I do knucklehead, it don't bend. I had a pair and returned them and I run 3:59 for 26.2, so I'm a fast fVcker:):):):)
You run 3:59 for 26.2? Hahahahahahahaha!!! Og gosh you gave me a good laugh. You are a slug.
I can race-walk it in 3:52:09 on a bad day, and I don't even train every day anymore. Did I mentioned you I am almost 60?
capo wrote:
You run 3:59 for 26.2? Hahahahahahahaha!!! Og gosh you gave me a good laugh. You are a slug.
I can race-walk it in 3:52:09 on a bad day, and I don't even train every day anymore. Did I mentioned you I am almost 60?
Cool. At least he doesn't admit to race-walking.
exrunner wrote:
I’m loving all the wannabe materials scientists trying to get in on the Vaporfly discussion haha
This has been one of my favorite parts of these threads. As an engineer who has some but not much experience composites I have stayed completely away from going into any of the scientific debate about the shoes and how they function. I have very much enjoyed seeing those who have no idea what they are talking about getting roasted by those who actually do and seeing those who actually know what they are talking about getting roasted by those who are completely wrong. I think by now we all know you could be the world's foremost technical expert on something and some knucklehead on Letsrun will be there to tell you how wrong you are.
What a clown. All kinds of bendy things are made with carbon. Bows in particular.
Technically it's the whole carbon epoxy matrix that does the work.
The bow may be the best example so far, and the phrase, "does the work," as well. You do work to bend the bow (which obviously does bend), and store potential energy in the spring. When release, the bow returns to its original shape and does work to accelerate the arrow.
I could absolutely believe that the same principle could be applied to a running shoe. When you bend the spring, that work that you are doing to bend the spring/plate is subtracted from the work that moves you forward, but I could imagine that the potential energy stored in the spring could be utilized in an efficient manner. The action of the spring would have to be coupled nicely with the fairly complex motions of running.
On the other hand, I could see your energy lost to doing work to compress foam or bend a poorly designed spring that would negatively effect running. It's more about design than materials.
Djjrjrjrjr wrote:
It bends or doesn’t bend depending on how one arranges the layers of fibers.
That has been my experience in my work in graphite epoxy composite fabrication for the US Navy. So, yes.
I didn't see carbon fiber bend because it cannot bend. It CANNOT! Also, that's not graphite on the ground!
I’m a D2 female runner. Our coach explicitly told us not to visit LetsRun forums.
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