Review: Asics GEL-Nimbus 21 vs. Nimbus 20 – See the difference here!

Review: Asics GEL-Nimbus 21 vs. Nimbus 20 – See the difference here!

Asics GEL-Nimbus has gone through some big changes in this year’s version. Asics has actually changed almost all of the parts of the shoe… Our running expert has tested the Nimbus 21 for the last month. Here is his review.


The top is new. The heelcap is new. The insole is new. The midsole is new. The outersole is new. Because of this, the fit is also different. As you can see, not much of the Nimbus 20 is left. If this is good or bad is something you can hear about in the following article where I go through all the changes and what they mean for the shoe.



If I wear the Asics GEL-Nimbus 20 on one foot and the Asics GEL-Nimbus 21 on the other, I can easily tell the difference between how soft they are just by standing or walking. Nimbus 20 feels markedly softer, and it is as if my left foot (Nimbus 20) “sinks” more than the right (Nimbus 21).


asics gel-nimbus 21 vs. asics gel-nimbus 20


I found the reason by taking out the insole. As it turns out, the new Nimbus 21 has a new insole which is much harder than the insole in the Nimbus 20. The insole in the Nimbus 21 is made in relatively hard foam, while the insole of the Nimbus 20 reminds you more of a soft sponge. If it makes a functional difference when I run is hard to figure out, but there is no doubt that the Nimbus 20 feels softer and more comfortable than the Nimbus 21 at first hand.


asics nimbus 21 sål

Left: Asics GEL-Nimbus 21. Right: Asics GEL-Nimbus 20.


Buy Asics GEL-Nimbus 21 here 



The midsole is probably the most important part of a running shoe. This is where “the magic happens,” so to say. The midsole is everything you find between the insole (which you can normally pull out of the shoe) and the durable outersole (which touches the ground). Everything in between is called the “midsole,” and its construction is crucial for how the shoe feels beneath your foot when you run.


The new Nimbus 21 has received the same update in the midsole as the Asics GEL-Kayano 25 (top-range model for pronation) recently received. The midsole consists of Asics’ now most shock-absorbing material, the “FlyteFoam,” in two variations: FlyteFoam Lyte and FlyteFoam Propel.


Furthest back and at the lowest part of the shoe you will find the FlyteFoam Lyte, which is a light material with exceptional shock-absorption and which ensures a soft and comfortable landing. The new thing is that, above the FlyteFoam Lyte, you will find a new material called FlyteFoam Propel. This material gives the shoe even more bounce and even more return-energy – especially at the front foot (where it is exclusively FlyteFoam Propel).


asics gel-nimbus 21 mellemsål


The final result of the update is that the Nimbus 21 has in my opinion the best and most efficient launch in the history of the Nimbus collection. If you have been running in the Asics GEL-Nimbus earlier, then the version 21 will feel a bit firmer and with a quick response beneath your foot. But do not make the mistake of thinking that the Nimbus 21 is not still the softest and most shock-absorbing shoe on the market! The addition of the FlyteFoam Propel has made the shoe slightly less soft.

I personally prefer the slightly harder/firmer feel of the Nimbus 21 than the softer Nimbus 20, which can become a bit too “couch-like” and relaxed to my taste.


When you press down on the two materials with your fingers, you can easily feel the difference. If I should try to illustrate the difference of the FlyteFoam Lyte and the FlyteFoam Propel, I would say that:

-      FlyteFoam Lyte (the blue material) feels slightly like a sponge (though it is the hard kind), which is great for absorbing shocks but does not bounce back to its original shape that strongly.

-      FlyteFoam Propel (the white material) feels much more elastic and bouncier.

 asics gel-nimbus 21 test


To ensure the supreme shock-absorption which the Nimbus collection is famous for, you can still find the small GEL cushioning both at the heel and front. There is the same amount of GEL at the heel in the Nimbus 21 as in the Nimbus 20, but the GEL is not as prominent in the front of the Nimbus 21 as in the earlier model. Notice how the GEL cushioning in the front of the Nimbus 20 are large and visible (see the picture below), while the Nimbus 21 only has a little GEL cushioning in the middle of the front part of the shoe (the small blue “disc” in the video below)


asics gel-nimbus 21 vs. asics gel-nimbus 20

Asics GEL-Nimbus 21 (top) and Asics GEL-Nimbus 20 (bottom).



Video: The construction of the Asics GEL-Nimbus 21.



Asics has has kept the heeldrop of the Nimbus 20 and therefore there is still a difference between the men’s and women’s edition. The men’s edition of the Nimbus 21 has a heeldrop of 10 mm, while the women’s edition lies at 13 mm. The heeldrop is the difference between the height of the heel and the height of the front foot above the ground (measured inside the shoe). In the men’s edition, the heel is in that way 1 cm higher than the front foot, which means that the Nimbus 21 is a shoe that is especially fit for the runner who lands on his or her heel when running. More than 90% of all runners do that, by the way. So, if you are not sure of how you land, you can assume without worry that you land on your heel.


Buy Asics GEL-Nimbus 21 here 



Many changes have taken place in the bottom of the shoe. The characteristic “Guidance Line,” which runs from heel to toe in the middle of the sole and which has been set part of the Asics running shoes for many years, has now been shortened. And the supportive TRUSSTIC resin  in the midfoot, which helps stabilize the shoe and counter twists, is now only to be found in the medial side (on the inside of the foot). This has been done to save on the weight of the shoe, and the rest of the construction compensates the change in full, so that the shoe is not less stable. The Nimbus 21 is actually MORE stable and counters twisting better than the Nimbus 20!


The outsole/midsole has at the same time become about 5 mm wider than the Nimbus 20. Such a wide base/platform only makes the Nimbus 21 even more stable.


asics gel-nimbus 21 vs. asics gel-nimbus 20 ydersål

Asics GEL-Nimbus 21 (left) and Asics GEL-Nimbus 20 (right).


Even though the Nimbus is characterized as a neutral running shoe, it is very close to being in the supportive stability/pronation category. It is more stable and absolutely the most supporting, controlling, and guiding running shoe, if you compare it to the other top running shoes on the market for the neutral runner: Saucony Triumph ISOBrooks GlycerinNike VomeroNew Balance 1080, and Mizuno Wave Sky.


Asics Nimbus 21 seems generally as an incredibly durable shoe. It is made for long runs, and I am sure that it has a lot of kilometers to give. Currently, I have run almost 100 km in them and have not seen any wear worth mentioning. 



If you belong to those who complained about the tight fit of the Nimbus 20 and especially the Nimbus 19 (which was very narrow and tight fitting): Your prayers have been heard! 


asics gel-nimbus 21


The toebox in the new Nimbus 21 is much roomier than the latest models. It is both roomy in the width and above your toes. Even if you have a narrow foot there is no need to worry – the lacing system is greatly designed and lets you tighten the shoe a lot while still finding the fit great. The laces are also more elastic than earlier, with the effect that you can really tighten the shoe without worry. The reason is that the laces stretch a bit more when your foot changes its shape during the toe off.


If you view the shoe from above, it is easy to see that the Nimbus 21 has a more rounded toe compared to the Nimbus 20, which is pointier.


asics gel-nimbus 21 vs. asics gel-nimbus 20

Left: Asics GEL-Nimbus 20. Right: Asics GEL-Nimbus 21.


The upper of the Nimbus 21 is made in a new engineered mesh with multiple layers. It is claimed to be more breathable than earlier, but I have found it very difficult to determine if that is the case. Yet, what I can determine is that the fit is exceptional! You really get the feeling of a high quality and great comfort when you wear the Nimbus 21. In addition, the upper is supplied with a 3D-printed rubber enhancement at the places on the shoe where your foot needs the most support.


asics gel-nimbus 21 vs. asics gel-nimbus 20 

Left: Asics GEL-Nimbus 21. Right: Asics GEL-Nimbus 20.


Buy Asics GEL-Nimbus 21 here 




The heel counter of the Nimbus 21 has generally become more stable.


asics gel-nimbus 21 hæl


Compared with the Nimbus 20, the design is more rounded so that the shoe holds your heel better than earlier. The supportive plastic frame external to the heel has at the same time become firmer. Because of this, the Nimbus 21 has become markedly more stable and supportive around the heel. Yet, it is still not that close to the extremely stable heel counter of the Asics GEL-Kayano 25. But when it comes to the shoes that the manufacturers themselves call neutral running shoes, the Asics Nimbus 21 is without a doubt the most stable shoe I have tested! And that is not only thanks to the heel counter. The other changes that I mentioned earlier have also contributed to this increased stability. 

 asics gel-nimbus 21 vs. asics gel-nimbus 20 hæl



I have seen other distributors of running shoes call the Nimbus 21 an “incredibly light shoe” which helps improve your personal records. This description is in my opinion outright misleading! The Asics GEL-Nimbus 21 is in no way a light shoe. It is among the heaviest running shoes on the market and is actually 2 grams heavier than the Asics GEL-Nimbus 20 (310g vs 308g). So, it is not a record-breaker… And that is not really a problem, because it has never been the intent that the Nimbus should be a light and fast shoe. The Nimbus is a running shoe built for long distance runs and to provide the runner with maximum comfort and protection on daily runs. And it certainly lives up to this! 


asics gel-nimbus 21 review


Asics GEL-Nimbus 21 is not made for speed runs or to hunt personal records. If you are looking for a shoe to do this, then you should instead look at the Asics Dynaflyte or the Asics Roadhawk FF, for example. I have taken a closer look on these in the following article:



Buy Asics GEL-Nimbus 21 here 



If I should sum up and point out the biggest and most important updates of the Asics GEL-Nimbus 21, then it is the following:


- Excellent fit.

- More room for your toes.

- More stable and supportive.

- A firmer and faster feeling beneath your foot.


Even though Asics have made a lot of changes to the shoe, it still feels like a Nimbus. Here you get maximum comfort! The 21st edition of the by now legendary Asics GEL-Nimbus is a really great running shoe and a safe choice if you seek a reliable workhorse that both provides support and comfort on those long, daily runs.


The test was conducted by Jesper Petersen, Physiotherapist and Running Expert at

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