As a result, the bottom heavy feel was more obvious as the stack numbers increased. ZF1 and 2 were 35/25 stack heights, ZF3 went to 37/29 just like the Next%.

For reference, 4% was a 34/24 stack height, Next% is 37/29. ZF3 changed up the stack height and silhouette completely, mirroring the change from 4% to Next%.

(The same could be said of the 4% flyknit) The upper was terrible unless you have very narrow feet. A little bottom-heavy but the ride was bouncier and more forgiving. ZF2 went all-React for the midsole, and the plate got upgraded to the same carbon plate as the 4%. Many people still think the SP upper is the best ZF upper of all. ZF SP was marketed more as an athleisure shoe but I actually used it for a couple of races because it was a more minimalist upper with the same aggressive rocker. I liked it for long runs and it was great for holding uptempo efforts, but it was probably too firm for the majority of casual runners. And in terms of the ride, you either loved it or hated it. I liked the fit and lockdown of ZF1, both at true to size and a half size up, but I know of people who had abrasive issues with the heel counter. Nike has never quite managed to get it all right with this model. Since then the ZF has gone through several iterations, and I think it’s fair to say it’s been hit and miss with the majority of runners. I was a big fan of the shoe from the outset and went on to use it to break a 3-year-old marathon PB in 2:41:10 back in July of 2017 (less than a month after it was released for sale). The OG Zoom Fly 1 was arguably the first plated maximalist shoe to enter the public consciousness from a mainstream brand. The Zoom Fly range has strong sentimental value for me.

Nike zoom running