Z50 - Lightweight Training

ENGINEERING SPECS: Average adult ranges for height, cadence, and body weight at this pace.

CUSHIONING: At 8 minutes per mile, your flight distance is long, which means you generate quite a bit of force when you land. To account for that specific impact force, we tune the reaction density of the heel and midfoot to optimize the cushioning you get. Forget about a "max" cushioned shoes made for who-knows-who—the Z50 gives you the best cushioning possible when running within the pace zone. We call this pace-tuned cushioning. Pace-tuning is the only way to get optimal cushioning in the running shoe you wear. 

PROPULSION: At this pace it takes a lot of force to propel yourself forward, so the last thing you want is a squishy, inefficient midsole. We’ve tuned the forefoot FastPods in the Z50 to deliver maximally efficient energy return given the forces at this pace.

DROP: Runners at this pace are usually light to average weight and often midfoot strikers. With this in mind, we built a 5mm drop into the Z50. This helps prevent a negative heel drop angle upon impact. 

SOLE DESIGN: Rocker design and fortified arch outsole for ideal propulsion. According to a recent paper on arch compression, forces on the arch are greatest during the push-off phase of your stride (not the impact phase). Many shoe designs carve out the arch area, exaggerating pronation. The Z50 fills the arch area to provide support during push-off, precisely when you need it.

MIDSOLE MATERIAL: Vimazi Z-Foam has an EVA (ethylene vinyl acetate) base. Proprietary additives have been mixed into the EVA to increase abrasion resistance and elongation properties. Most importantly, however, we use our specific EVA blend because it allows us to dial in an ideal compression set for each model. This isn’t possible using other common midsole foams. Finding a foam matrix that could be specced to specific durometers was one of the reasons it took five years to develop and produce our pace-tuned shoes. Our midsole formulas are the heart of the technology. They’re what allow us to tune the Vimazi Z50 to a peak force spec of 800N in heel/midfoot and 1250N in forefoot (W11.5). No one else does this, and you can't tune shoes in this way using other midsole foams.

Everyone who runs 8 minute miles wants superior cushioning but without sacrificing any push-off efficiency. We all generate a wide range of both impact forces and propulsion forces while running. The forces at 8 minutes per mile are much different than the intense forces at 5 minutes per mile or the gentler forces at 12 minutes per mile. 

We studied how midsole material responds to the forces at different running speeds. We found that it’s impossible for one midsole foam to respond in the way you would want at all paces. So what does that mean? It means that midsole densities need to be adjusted to the pace of the runner. (This is a problem for running shoe brands that market every shoe to every runner, irrespective of pace.)

Our research also showed that the propulsion forces in your forefoot and toe are greater than the impact force you encounter in the midfoot and/or heel. As a result, it’s critical that running shoes are tuned by both pace and between heel and forefoot. At least if you want to run in the best performing shoe. 

By adjusting midsole density in the heel and midfoot to the forces you generate at 8 minutes per mile, you get the exact amount of cushioning you need at that pace. Goldilocks cushioning! Pace-tuned cushioning in the Vimazi Z50 ensures stability during push-off, plus gives you the comfort and health benefits of reduced shock. 

But you wouldn’t want better cushioning to get in the way of a propulsive push-off (which is a problem in many running shoes). To get the energetic push-off you want, the forefoot has to be tuned differently from the heel. We’ve engineered the forefoot FastPod in the Z50 so it reacts to the propulsion force you generate at 8 minutes per mile. 

The result: The Z50 reduces shock while increasing efficiency when running between 7:00-9:00 minutes per mile (4:30-6:00 minutes per kilometer).