We should at this point bear in mind that for the purposes of legality in World Athletic rules, the stack heights of shoes include the thickness of the insole (aka sockliner), something which I feel has never been universally adopted as standard practice in the declaration of stacks by manufacturers, but which I think is a reasonable approach considering World Athletics’ goal is to limit stack underfoot, rather than to know the correct stack of each shoe. I also took the opportunity to measure the stack heights of a few other shoes I had, partly to use as a reference point, and partly out of curiosity about the veracity of the stack heights of shoes, as declared by manufacturers. With that in mind, I decided to explore a more accurate way of measuring the stack height, one as close to the IAAF official rule standards for the measurements, short of sawing the shoe in half to obtain the numbers. You can see from the pictures, that the Tempo does have a lower apparent stack than the Alphafly.

Advertised stacks sometimes deviate quite substantially from the measured stack, and ultimately it only matters how the shoe feels when you run in it.ĭue to the scalloped designs of both shoes, it is difficult to get an accurate measurement of what the actual stack is, especially with the glued in insole of both shoes. This is of course a considerable deviation from the published stack heights for the Alphafly. Tempo Forefoot 36mm, Heel 46mm for a 10mm dropĪlphafly Forefoot 41mm, Heel 50mm for a 9mm drop Bearing in mind that the platform is scalloped in both the forefoot and the heel, I measured the stacks from the outside as follows: Assessment of Stack Heights of Running ShoesĪfter recently reviewing the Nike Air Zoom Tempo Next% Flyknit, which does not have any published stack numbers from Nike, I did some manual measurements of the midsole/outsole stack from the outside of the shoe.

Nike air zoom superrep 2 heel height