ASICS is trying to solve the problem of billions of shoes which are sold and unrecycled every year. They have had to make some pretty impressive technological leaps to do so. The result of this is the Nimbus Mirai.
ASICS Nimbus Mirai: The Technology of Sustainability
When looking into improving their sustainability ASICS found a couple of problems. Firstly, uppers were made of too many different materials making them very hard to recycle effectively. Secondly, the glue used to hold running shoes together was too strong, making shoes too hard to deconstruct. With the Mirai, ASICS looks to solve these issues. Initially, they took the problem of the upper and created a mono-material solution. Everything on the upper is the same material. Eyelets to heel tab. Laces and stitches.
Furthermore, the problem of the glue. How to make something which holds up to the rigours of daily running yet can be easily dismantled in their after-life. ASICS solution is a glue which can be heated in an oven and taken apart easily. Inspired by the town of Kamikatsu, Japan which made a 0 waste pledge in 2003 and is on their way to hitting in 2030, the goal is to be better than the 95% of the 20 billions bits of footwear which are landfilled every year. Working with Terracycle, ASICS says that 87.3% of the Nimbus Mirai comes back as new material for re-use in other shoes.
This is all very good but does the shoe perform its basic task as a running shoe? It is a shoe designed to be returned but will that be early or at the end of its life?
Specs:
Product details from ASICS
Release Date: 12 April 2024
Price: €200
ASICS Nimbus Mirai Upper: Scientific Simplicity
Initially, for me, this is a beautiful upper. The unbleached, mono material with no overlays looks super clean and fresh. Initial step in comfort is very high. From the off, the upper wraps the foot well. The gusseted tongue really helps wrap the midfoot and hold it in place. There is some give in the upper, not quite as much as previous versions of Nike’s Flyknit material but it is not a stiff knit. The lack of overlays isn’t really an issue. During all of my runs so far, I have felt comfortable and the lockdown has been simple to achieve.
Furthermore, the Nimbus Mirai fits true to size for me. There is a little extra volume in the upper which has meant that I have needed to pull the laces tight but moving half a size down would have made the shoe too short. The tongue, while thin, provides enough protection for the foot from the laces even when pulled hard. To further show the commitment to recycling the Nimbus Mirai has a QR code printed on the tongue which leads to instructions for return and recycling.
At the rear of the shoe, the pull tab, being made from the same material as the rest, is less elastic than that of the Nimbus 25. It is attached to a heel cup which is fairly stout and the padding around the collar helps with the lockdown and comfort. So far, the longest run I have taken in the Nimbus Mirai is 15km and I have had no issues with comfort or rubbing. This is just as well as blood and other stains will show up very clearly on the blank canvas of an upper.
Overall, the upper does what it needs to. It holds the foot well and in comfort. The laces have a little give and are long enough for a runner’s knot in the highest set of eylets.
Midsole: Stable Shock Absorber
Continuing the eco theme, the FF BLAST PLUS ECO midsole is 100% recyclable while also being made from 24% renewable sources. Initially, it is obvious that the midsole is nowhere near as thick as the huge slab of foam in the Nimbus 25 and 26. To the thumb, it feels very soft. However, on the run, it feels a little firmer than expected. Whilst this is not an unpleasant feeling, it definitely sits more with the PUMA Velocity Nitro 3 than more maximalist options.
I have taken the Nimbus Mirai on both easy jogs and more uptempo sessions and it has performed well on both. For my tastes, it is a fairly versatile midsole. On one hand, it is stable, shock absorbing and smooth to transition through the gait cycle. On the other, it does not have a great pop to it. FF BLAST PLUS ECO does a good job of being responsive, when I took it up to my marathon pace, it was comfortable and capable. However, I would not want to run a full marathon in them.
ASICS claim that there is no hit to durability with their move towards sustainability. After 40km in the Nimbus Mirai so far, I have no reason to doubt this claim. Other than some mottling from muddy pavements, there is no sign of wear to the sidewalls or exposed foam on the sole of the shoe. As I contunue to put miles into the Mirai, I will update this with further news on the durability.
ASICS Nimbus Mirai Outsole: Grippy Goodness
On outsole duties, ASICS gives us HYBRID ASICSGRIP and AHAR+. During my testing time so far, I have been subjected to some pretty wet days. Thankfully, on each of these, the outsole has performed its duties well. Through puddles and mud spills, I have had no issue with the grip. Even when escaping the lightning on a beachfront run, I had to scamper up a wet, gravel path for shelter and the Nimbus Mirai outsole didn’t let me down.
Again, at this early stage of testing, I have noticed no smoothing or degradation of the outsole. I will update the review when I reach the 100km mark.
ASICS Nimbus Mirai Conclusion: Dependable, Sustainable and Beautiful
Thankfully, we are seeing more and more companies taking their environmental impact seriously. Furthermore, they are also producing shoes which do not sacrifice performance for sustainable goals. Recently we have had the hylo Impact and last year the Saucony Triumph RFG. For me, the Nimbus Mirai sits somehwere between these. It has a lot more structure and stability than the hylo. The Mirai will take you over whatever distance you choose to take with no ill effects. However, it does not have the depth of cushion and pop of the Triumph RFG.
As a dependable daily trainer with a clean environmental conscience, the Nimbus Mirai does the job very well. It offers versatility and stability while retaining comfort and cushion. I look forward to putting more miles into the Mirai and also seeing where else ASICS takes their material advances in the future.
