pcli5kdoc wrote:
Milethon wrote:
I haven't tried the Alphaflys but from the reviews and descriptions, I'm going to stick with the Next% . They are about as perfect as a shoe can get for me, unless Nike can figure out a way of shaving off an other ounce or two. Also a trail version of it would be pretty cool.
Do you think we might see a 1-2 oz reduction prior to Tokyo?
I would say objectively no chance and here is why
1) The uppers on the lightest of their elite product (the nxt%) are already are as minimal as possible and to be honest pretty terrible. They had to use a non-breathable ripstop on the nxt% in order to have an upper that had no internal reinforcement etc because it would add weight (ie. a mesh with any sort of physical openings in it for breathability/airflow would simply stretch too much and need added support). They nicely framed it up as "water resistant to stop water soaking into the shoe and adding weight" but really it's a crappy but very lightweight upper.
2) Outsole rubber is the densest material used on footwear so they try and keep that to a minimum. Hard to see where you use less rubber than on the current nxt.
3) Midsole unit (foam and plate). Here is the thing - the key biomechanical advantage is created by the curvature of the plate and ability of the foam to compress into the void, creating a 12-14mm "drop". So when you think about it that way, the midsole needs a certain geometry in order to do these things a) have some foam between the plate and the outsole rubber - around 10mm b) house the plate (around 2mm) and c) have that 12-14mm for the "drop". So that means forefoot wise around 26mm for the actual foam unit. When you add in the rubber and the sockliner and then adjust the rearfoot to create the basic forefoot to rearfoot drop, you end up right at the current limits of World Athletics rules.
So what's my point? The way to reduce weight on this shoe is to reduce the midsole unit but doing so takes away from the running economy improvement levers/factors the shoe has. In that respect the only way you make this shoe lighter and keep those factors is to use a lighter rubber and/or foam and considering the foam is some ridiculously low density already (in the 010-012C range), there isn't much to play with that could ever see you dropping 1-2 ounces.
If Nike could squeeze this down even 14 grams (which is 1/2 an ounce) and keep it as economical it would be amazing.