Our verdict

The Cumulus 21 not only met my expectations but exceeded them! It's got the chunk, but all for good reasons. It's protective, and luxuriously comfy, and it doesn't let the feet feel beat up after long sessions on the road! It rolls smoothly and it's pleasant to my feet, which is why I found it great for running ultras. More importantly, for a neutral shoe, it feels very stable.


  • Very smooth ride
  • Stable platform
  • Sufficiently padded for ultras
  • Comfortable, luxurious upper
  • Exceptional build quality


  • Not a responsive midsole
  • FlyteFoam is heavy

Audience verdict


Why I recommend the ASICS Gel Cumulus 21

The Cumulus 21 is a beefy workhorse capable of eating up many road miles. I had my reservations with ASICS before running in the Cumulus 21 but now I understand why so many people are die-hard ASICS fans.

The Cumulus is now the first shoe I pick up for my long 3-hour plus weekend runs because I know that my feet will be well protected and the upper won’t give me any blisters.

What sets the Cumulus apart from competitors in the neutral daily trainer category such as the Pegasus, Ghost, and Wave Rider is that the Cumulus has an extra layer of underfoot softness making it more comfortable for super long runs.

Following the releases of the Cumulus 21 and the well-received GlideRide, I get the feeling that ASICS has turned a corner and will now produce hit after hit. I can’t wait to see the new releases ASICS has in store for us in 2020.

My expectations for the Cumulus

I haven’t really been excited for an ASICS shoe in the last couple of years. My last ASICS shoe was the Nimbus 19: it was expensive, heavy, and didn’t wow me.

It was the first Nimbus to have FlyteFoam in the midsole and it felt very, very firm bordering on hard.

Here in Asia, ASICS is the most popular running shoe brand. Going for long Saturday runs, more than half of the runners I pass wear ASICS shoes (mostly Kayanos).

Whenever I passed them, I would think to myself: shame, it must be torture to run in such a heavy, firm shoe. I didn’t get what all the hype was about.

I only bought the Cumulus 21 because it was on sale at a ridiculous price. I chose the Cumulus 21 because I have read reviews stating that the Cumulus 21 is actually softer than the Nimbus 21, its older, more expensive big brother.

I wanted a long-distance trainer that I could use for distances longer than 25 kilometres while I train for a marathon.

Upper & Fit

The Cumulus 21 upper is made from Jacquard mesh. It’s thick and plush and feels as luxurious as a Brooks upper.

It has plenty of forefoot room if you have wide feet and is plush enough to stop your foot sliding around if you have narrow feet. The heel is padded with lots of spongy foam and grips the heel well.

While the Cumulus upper construction is very old school, ASICS keeps it modern with fused overlays and attractive colour schemes. In my opinion, ASICS is the best brand at choosing colourway designs.

I bought the LS (Lite-Show) version of the Cumulus 21. This version has extra reflective lacing overlays as well as reflective paint on the midsole.

The Lite-Show version came out a couple months after the normal version.

The Cumulus 21 upper is one of those superlative uppers that you lace up before your run and you don’t have to worry about it for the next 3 hours or however long your run is. No lace adjusting needed, no hot spots, no heel-chaffing. It just works well.

Midsole & Ride of the Cumulus 21

The midsole consists of two different types of FlyteFoam: Propel and Lyte.

One of them is bouncier and more responsive while the other is firmer and more resilient. Honestly, I can’t tell any difference between the two foams- they are very similar in densities.

My first run in the Cumulus 21 reminded me of a certain shoe I had a year ago: the Nike Structure 22. The Cumulus 21 feels like a more cushioned, softer Structure 22.

The ride feels very planted and smooth with a pleasant sink-in feel and none of the rigidity of the Structure.

While the Cumulus 21 is not a super soft shoe like the New Balance Propel or the Pegasus Turbo 2, it is a very padded shoe and excellent at absorbing shock. If you remove the insole, you can feel the soft, spongy layer that provides sink-in comfort.

The shoe is advertised as having rearfoot and forefoot gel but that’s just a marketing gimmick.

There is only a small amount of gel in the heel and a coin-sized gel unit in the forefoot which doesn’t do much as far as cushioning is concerned. The type of foam used is where the shoe gets it's cushioning from.

While the Cumulus 21 provides cushioning and support for long distances, it doesn’t offer any bounce or responsiveness. I use my Cumulus 21’s for super long distances of 30+ kilometres when I want lots of foot protection and I don’t mind having a low cadence or minimal ground feel.


Being a supportive neutral shoe like the Ghost, Pegasus and Wave Rider, the Cumulus 21 is also very stable.

The midsole foams are not overly soft so there is no lean bias. I have flat feet and I pronate but the Cumulus 21 has plenty of support and never caused me any injuries or discomfort.


The grooves on the outsole span the entire width of the forefoot, making the Cumulus 21 very flexible. Even though ASICS has removed the plastic shank in the midfoot, the shoe still flexes in the correct place- in the front of the shoe.

Outsole & durability

There are two types of rubbers used in the outsole: AHAR (ASICS High Abrasion Rubber) and Durasponge.

The AHAR is the more durable material covering the high wear areas such as the heel. The Durasponge is made of softer, blown rubber which is lighter and has more road feel.

The older ASICS shoes were guilty of having hard outsole rubber lugs attached to much softer foam with a wide guidance line. The result was that you could feel the edges of the hard lugs through the shoe which was lumpy and uncomfortable.

I’m glad ASICS has fixed this issue by making the guidance line narrower and making the midsole softness more balanced throughout the entire midsole.

After putting 50 miles on my pair, there is very little wear on the AHAR section with some slight wear on the Durasponge which lies under the ball of my foot.

The Cumulus 21 feels like an exceptionally made shoe capable of going well over 800km. The luxurious upper and the well-constructed midsole show no signs of weakness.


The non-Lite Show version of the Cumulus 21 has a smooth, compression-moulded insole. The Lite Show version has a blown Ortholite X-40 Sockliner which is softer and spongier than the regular compression-moulded one.

This results in an overall softer-feeling ride. Ortholite insoles claim to have less than 5% compression over time ensuring you never lose cushioning while also being made from open-cell PU foam to allow air to circulate in and around the insole.

I’m not sure why ASICS decided to change the insole to Ortholite but it’s a change that I welcome because I prefer a softer ride with more protection for my delicate feet.