The Vaporfly 4% Doesn’t Work how you Think

That would explain why they wear out so fast....carbon fiber is almost indestructible.

Da F is Grand Valley State University. Who's funding this research anyway. I have one guess and there's a 4% chance I'm wrong.

Then Nike should remove the plate and no one will have a problem...

Don’t the peg turbos have the same foam, sans plate?

Test the turbos wrote:

Don’t the peg turbos have the same foam, sans plate?

50% zoom, 50% react.

coachcommentsnicely wrote:

Test the turbos wrote:

Don’t the peg turbos have the same foam, sans plate?

50% zoom, 50% react.

So vaporfly 2%????

I am we todd did wrote:

Da F is Grand Valley State University. Who's funding this research anyway. I have one guess and there's a 4% chance I'm wrong.

GVSU is a 25,000 student D2 school in Michigan. They have one of the best D2 XC teams in the USA. Their track team is sponsored by Adidas.

"The bending of the carbon fiber plate stored and returned energy at a rate of 0.007 watts per kilogram with each stride. In comparison, the squashing and unsquashing of the thick ZoomX foam returned 0.318 W/kg—more than twice as much as either of the other shoes, and about 45 times more than the plate"

Anyone got any insight on how exactly they came up with this? Did they completely remove the plate from a pair and test it in isolation?

Fun Lovin' Boyz wrote:

"The bending of the carbon fiber plate stored and returned energy at a rate of 0.007 watts per kilogram with each stride. In comparison, the squashing and unsquashing of the thick ZoomX foam returned 0.318 W/kg—more than twice as much as either of the other shoes, and about 45 times more than the plate"

Anyone got any insight on how exactly they came up with this? Did they completely remove the plate from a pair and test it in isolation?

mmm, that is weird dude. If you google both these w/kg numbers you get nothing back apart from this article!

Test the turbos wrote:

Don’t the peg turbos have the same foam, sans plate?

It's a mixture of that "React" garbage and the good ZoomX stuff. A pure ZoomX shoe with no plate would be very unstable.

Isn't that basically the Reebok run fast pro? Doesn't seem to be garbage per reviews.

React Foam SUCKS wrote:

Test the turbos wrote:

Don’t the peg turbos have the same foam, sans plate?

It's a mixture of that "React" garbage and the good ZoomX stuff. A pure ZoomX shoe with no plate would be very unstable.

React seems to me, to be just a bit better Lunarlon, which seemed to be a better Phylon. You really don't go for React, I take it.

plebe wrote:

Isn't that basically the Reebok run fast pro? Doesn't seem to be garbage per reviews.

Yes, but the Reebok midsole is incredibly thin, so even though it's compliant, it doesn't compress all that much in absolute terms. It's likely the Vaporfly's combination of thickness and squishiness that makes a plate necessary for stability.

well actually wrote:

Then Nike should remove the plate and no one will have a problem...

Ha ha, yes exactly.

Who'd have thought it, it's just a coincidence that the first shoes with the big carbon fiber plate in them are smashing World Records, it's really just down to Nike's magic snake oil foam!

So judging by the article, (didn't read article) the nike Zoomfly should be just as performance enhancing?? I don't think it is. (I have not wore either shoes.)

They used a bending machine on the plate and then tried to calculate what it would return on the foot. I'm not spending $45 on the paper, so can't see their justification. The videos of the shoe flying through the air after being bent and released make me skeptical.

Even if it is right, how do we know they don't give better springs to their chosen ones? It would be a neat trick if we get 4% while Kipchoge has 10%. He can decline with age and go easy on other sources of assistance and we would never know. Just give him a slightly better spring every year.

It's ok though. Nobody paying attention believes anymore anyway. At least this time they are telling us it is fake.

that's exactly the opposite of what it's saying

plebe wrote:

Isn't that basically the Reebok run fast pro? Doesn't seem to be garbage per reviews.

I believe the Run Fast and Run Fast Pro are a mix of PEBA and EVA foam. The EVA serves the same function as the carbon plate to stabilize the shoe.

MobileReply wrote:

They used a bending machine on the plate and then tried to calculate what it would return on the foot. I'm not spending $45 on the paper, so can't see their justification. The videos of the shoe flying through the air after being bent and released make me skeptical.

Even if it is right, how do we know they don't give better springs to their chosen ones? It would be a neat trick if we get 4% while Kipchoge has 10%. He can decline with age and go easy on other sources of assistance and we would never know. Just give him a slightly better spring every year.

It's ok though. Nobody paying attention believes anymore anyway. At least this time they are telling us it is fake.

They used a motorized force-measuring treadmill and motion capture software to determine the positions of the joints relative to the treadmill.

Here are some relevant quotes about the plate vs midsole:

"We estimate that if mechanical energy is stored in and returned from the NP’s carbon-fiber plate at the MTP joint, this would be at a rate of about 0.007 W/kg at most, providing ~ 35% of the posi- tive work rate at the MTP joint, but to put it in perspective, only ~ 0.3% of the positive work rate at the ankle (Table 3). This strongly suggests that, rather than being a spring, the carbon-fiber plate acts in parallel with the intrinsic foot mus- cles to stiffen the MTP joint."

"The NP midsole returned more than twice as much energy from compression as the other shoes, but the magnitude was only 0.17–0.18 W/kg more. Noteworthy, the NP midsole returned 0.318 W/kg from com- pression and just 0.007 W/kg from bending the carbon-fiber plate and midsole, almost 50 times more."

So basically it sounds like they look at the ankle and MTP joint (toes) and measure the amount of force delivered to/from those joints by your body and shoes to propel you, and they found that the effects were determined by the behavior of the foam, rather than the plate, as far as they can tell.