Asics Gel Nimbus 21 vs 20 Comparison Shoe Review

Josh gives you the low-down on the new Asics Gel Nimbus 21 running shoe and provides an informative comparison with its predecessor, the Asics Gel Nimbus 20. 

This high mileage neutral running shoe provides an orthotic-friendly upper and customised heel fit to move with you as you hit the road. Asics have stuck with what works, transferring the popular FlyteFoam cushioning of their running footwear to this re-engineered model. 

When weighed up against the 20, the Asics Gel Nimbus 21 provides road warriors with a softer feel underfoot without compromise to responsiveness. It features a full ground contact outsole, comes in multiple widths to find your perfect fit and accommodates both heel strikers and midfoot strikers. 

Check out the review with full transcript below. 

Hi guys, Josh here from Sportitude and today is shoe review time and it's going to be the new Nimbus 21.

I have the ladies' here and the men's as well. It's been on the market for a couple of months. Some of you out there you may be familiar with this shoe, but there's a fair bit that Asics have changed to the engineering of this shoe.

I wanted to wait a few months to analyse and get some feedback from runners in the field to give you a bit more information whether it's a yay or a nay.  

Structurally it's the high mileage neutral shoe in the Asics running family. It has a pretty generous stack height of 31mm heel and 21mm forefoot, so a 10mm variance in both men's and women's. 

It's a plush running shoe. For those Nimbus wearers previously that know the history of this shoe, you know it's got plenty of cushioning inside this construction. It has a heel pod, forefoot pod and layering of different foam densities to get the best in regard to impacts and cushioning or dampening and also some responsive feel through the forefoot  

Like all my shoe reviews what I like to do is start from the ground and work my way up. We'll go outsole, midsole and then upper.  While I'm doing that I'm going to compare it to the differences from the previous Nimbus 20. Let's see if we can give you some information at home on how they differ.  

Outsole  

All things outsole. As I show you underneath what we have is some decent exposed rubber on the lateral side of the heel. It's a lot harder to take that dampening to protect the midsole on the first point of contact on the ground for heel strikers.  

As we come down through the midstance phase you can actually see we've got full ground contact.   What we've experienced in Nimbus gone by in the past is that we've had a Trusstic beam that sits between the medial and lateral side to give some rigidity through midstance.  

However, Asics have done away with that in this specific model and have gone full ground contact on that lateral side. As we come through the forefoot we've got horizontal flex grooves. We haven't seen horizontal flex grooves in this shoe for a number of years and let me show you why.  

The Nimbus 20 in my hands is the men's version. As I tip it upside-down, you can see what I'm referring to in regard to first and foremost that midsection or the Trusstic beam. It has a medial and lateral Trusstic beam to keep the foot nice and stable.

In regard to the new Nimbus 21, we've got a medial beam but no lateral beam. It's all full ground contact as you go through the gait cycle. It makes it a little bit more plush on that first point of contact with the ground for a midfoot striker.

We do know this shoe engineering-wise does sort of target a heel striker. However, they do accommodate a midfoot striker quite well, keeping that lateral side nice and stable in the new Nimbus 21.  

As we come through the forefoot, I want to highlight the horizontal flex grooves versus the Guidance Line we experienced previously in this shoe.  

The Guidance Line in the Nimbus 20 runs right down the middle. It offers a relatively smooth transition through the gait cycle, remembering this shoe is for a neutral runner with a higher arch or a borderline supinated foot type.  

A lot of the pressure is going to be on the outside of the shoe. Hence, Asics did have this Guidance Line previously to try and encourage a more natural toe-off phase through that forefoot. However, on the new Nimbus 21 you can see there's no Guidance Line.

What they've done is they've made it a little more flexible on the lateral side. They've got 1, 2 and 2.25 flex grooves you could say. On the Nimbus 21 we've got 3.5 flex grooves or there about, regardless how far they go across the foot.  

Naturally on that lateral side for a supinator it's going to be relatively flexible as well so you're not really loading up that lateral side, trying to get you to toe-off the appropriate metatarsals through the gait cycle.  

That's the difference regards to the outsole in the 21 versus 20.  

Midsole  

We are going to dial into the midsole now. No surprises, they've stuck with the FlyteFoam technology. You can see you've got the FlyteFoam top layer and then the Gel pod through the heel as well.  

What we've found previously with the Nimbus 20 is it was a nice soft shoe on the foot. However, the feedback that Asics got and we got in-store was it was a little bit too firm for what you'd classify as a plush cushioning shoe.  

This goes up against some really decent competition from Brooks Glycerin, Nike Vomero and the New Balance 1080 for example. It probably wasn't quite hitting the mark regards to that overall cushioning feel. 

Enter the 21. They've softened that feel underneath the foot, but not to the point where they've gone from one extreme to the other. They've certainly kept it nice and responsive. Put this on your foot, go for your run and on the first few steps you do notice that little bit extra underneath your foot and more noticeably for that heel striker as well.

Like I have previously, I obviously test shoes before I review them. I found my Nimbus 21 that I was running in to be nice and plush underneath that midfoot for me.  

I didn't mind the 20 but I wouldn't go grab a Nimbus 20 myself and go do some miles in it, it just didn't feel quite right. However, the Nimbus 21 easily slipped into my running closet and be a shoe I would select if need be.  

You get dampening cushioning through the FlyteFoam cushioning system and the top layer through here just gives a nice responsive toe-off as you go through your gait cycle.  

As I said before, we'll compare it to the Nimbus 20. Side by side you can see there's not a huge amount of difference between the two of them. They have exposed gel on the lateral side of the heel and that Twist Gel through the forefoot that you can't unfortunately see but it is there right under that first metatarsal.

It's the additional cushioning layer of the Nimbus 21 that gives you a plusher feel of the whole gait cycle.  

Upper

As we dive into the upper now let's talk about what's happening inside this shoe. Like they have these last few years, they've gone with an external heel counter device, that's just this little cradling beam that sits around your calcaneus.  

What that does being external just provides a little bit more of a custom fit, depending on the shape of one's heel. 

If someone has a slightly wider calcaneus base then this will give them a little more expansion. If they have a slightly narrower, it does pitch in as well. With the right lacing technique, you can get a really snug fit around the back of the heel.  

There's nothing really that has changed between the two. Structurally you see that there has been a bit of a change, but for the overall fit and feel I wouldn't lean towards one over the other, being 21 versus 20. They both have a nice and snug feel.

As we come to the middle of this shoe, we'll discuss how your foot feels regards to the upper and overall stability through midstance.  

What Asics have been able to do is just ever so slightly increase the depth of the shoe which has probably been a slight downfall with the Nimbus 20.

I'm saying this because it's an important topic. Nimbus is a very popular shoe for orthotics. There are obviously a number of shoes out there that can cater for an orthotic, but from an in-store perspective we probably see more orthotics going to Nimbus than we do any other neutral shoe in the Asics family. It's really important to have a little more depth in this area.  

Obviously when a brand engineers a shoe they don't put too much emphasis on orthotics going in. That's me telling you the truth at home because they try to structure the shoe for a neutral foot type. 

If we need to put an orthotic in there we can. Given there's a little more depth through here does cater for an orthotic quite well.

As we come through the forefoot, you get a slightly more rounded forefoot for more volume through that toe box, a little more real estate and toe room which is great and a fraction more depth as well.  

That just goes with the flow from the extra depth in the midfoot through to the forefoot. If they had the same depth through the forefoot as they did in the Nimbus 20, there would be too much of a contrast between what they're trying to achieve with extra space through here, through to that forefoot. It's a good consistent feel through this whole shoe. 

Widths 

Now let's dial in on the widths in this specific shoe because that's a really key factor as well. What I'll talk about is the men's first and we'll touch on the women's next.  

One thing I do want to dive into is that the widths do come in different colour options. The Asics Gel Nimbus 21 link will take you through the Sportitude landing page to show you what widths are available in each specific shoe.

First things first. For men's we have a standard D width, then we have a 2E and 4E on offer as well, so they do get extra wide 4E which is a really good feature about that shoe.

For women's we've only got two widths on offer. We have a B standard and then a D which is a slightly wider fit as well. Still having two widths is a great feature.  

I'm a firm believer that a good technical running brand will offer you widths. If they don't offer you widths, I personally don't think it really matters to them who runs in this shoe and who doesn't.  

When you have a brand that's putting in a lot of money, resources and engineering into a shoe, they should then reinvest their product and their development in offering their shoe in specific widths. Obviously Asics, Brooks, Mizuno and New Balance to name a few are very good at that.  

There you go guys that's the width options for the Nimbus 21.  

In wrapping up the Nimbus 21, from my perspective it is a softer shoe than last year. It's a fraction more generous in the upper which is great, it's going to provide a deeper fit. All in all it is certainly a very comfortable neutral running shoe.  

As always with my reviews if you have any questions about this specific shoe, please contact our Sportitude shoe experts. If you haven't subscribed already, please subscribe to Sportitude's YouTube channel.  

Until next time, happy running.