Our verdict

Nimbus, from the Latin for rain, is usually used in reference to storm clouds that carry rain, sleet, or snow. Running in the ASICS Gel Nimbus 25, however, is anything but stormy. Its generously padded upper cozily secures our foot in place while the truly cloud-like midsole provides a pillowy and bouncy ride that brings the fun to our daily runs. It’s certainly worth a splurge if comfort is top of the priority list when it comes to daily trainers.

Pros

  • Sweet marshmallowy ride
  • Feels surprisingly stable underfoot.
  • Great at gobbling up miles
  • Generously padded and extremely comfortable
  • Snug performance-style fit
  • No break-in period needed
  • Sleek and sustainable design

Cons

  • Lackluster breathability
  • Not for wide feet
  • Not responsive enough for high speeds
  • Budget buster

Audience verdict

89
Great!

Who should buy

The Gel Nimbus 25 is a great choice for: 

  • Runners who enjoy a plush and bouncy ride from their daily trainers.  
  • Fans of long distance running who want a well-cushioned shoe to comfortably melt the mile markers aways with
  • Runners looking for a maximalist daily trainer that still feels stable underfoot
  • Mild pronators who don’t want a dedicated stability shoe
  • Casual runners in the market for a comfortable shoe that’s also stylish enough for walks around town

ASICS Gel Nimbus 25 1

Who should NOT buy

Our feet sank into the Gel Nimbus 25’s pillowy midsole too much for it to be an effective tempo-training partner. For a daily trainer that can pick up the pace while still feeling plush underfoot, we recommend the Brooks Ghost 15 or the plated Hoka Mach X instead. 

We were disappointed by the Gel Nimbus 25’s performance in our breathability test. The shoe just doesn’t provide enough airflow to keep our feet ventilated during our test runs, with the Gel Nimbus 25 becoming a virtual sweat-bucket by the end of runs on muggy summer days. For a shoe that melts miles and not feet, we recommend the similarly maximal Saucony Triumph 21

ASICS Gel Nimbus 25 cut

Despite being named after what is essentially a storm cloud, the Gel Nimbus 25 clearly isn’t built to withstand extreme weather. Apart from the less-than-stellar breathability we just mentioned, our freezer tests reveal that the shoe’s midsole softness and overall flexibility are more negatively impacted by the cold than the average road shoe. For runners living in colder climates, we recommend the Brooks Levitate 6 which, as our tests demonstrate, is virtually unaffected by the cold.

Breathability

We pumped the Gel Nimbus 25 full of smoke to get a visual idea of how well-ventilated the shoe is. The upper looks airy thanks to all those perforations throughout the shoe, but the test clearly demonstrates that the tongue lets out the majority of the smoke while the rest of the shoe slowly chugs out a thin haze. This lackluster performance indicates poor medial airflow, with the tongue providing the redemption needed to earn the Gel Nimbus 25 a middle-of-the-road breathability score of 3 out of 5; explaining why we felt like we were running in a pair of toasters during our test runs. 

Check out the Gel Nimbus 25’s much breezier cousin, the ASICS Gel Excite 9 which absolutely aced our test by billowing out smoke quickly and evenly throughout the shoe.  

Examining a cross section of the upper over a light, we can see that it is only able to shine through the holes in the tongue while the rest of the upper material seemingly blocks it out entirely. 

The shoe’s ample padding and multi-layered upper mesh are the clear culprits of the Gel Nimbus 25’s poor airflow. While these elements contribute to the shoe’s overall comfort, it does come at the cost of making the shoe a toasty training partner that we wouldn’t recommend for hot summer runs.

Test results
Gel Nimbus 25 3
Average 3.8
Compared to 235 running shoes
Number of shoes
1
Breathability
5

Durability

Outsole hardness

We pressed our durometer against the Gel Nimbus 25’s AHARPLUS outsole to measure how hard the it is and got a marginally softer than average reading of 78.4 HC. In our examination of outsole materials in the lab so far, we’ve found that this level of hardness provides a healthy balance between hard and durable versus soft and grippy.

ASICS Gel Nimbus 25 outsole hard

For an in-depth look at outsole compunds offered by different shoe brands, check out this article that explores the matter using data we've collected in the lab so far. 

Test results
Gel Nimbus 25 78.4 HC
Average 80.5 HC
We use an average of four tests. The photo shows one of those tests.
Compared to 286 running shoes
Number of shoes
52.1 HC
Outsole hardness
93.0 HC

Outsole thickness

Using our caliper, we measured the Gel Nimbus 25’s outsole to be 2.9 mm thick which isn’t as much rubber as the average road shoe tends to have underfoot. Minimizing the amount of rubber, both in terms of thickness and total coverage, is an effective weight-saving measure that helps keep the Gel Nimbus 25 feeling cloud-like rather than brickish underfoot. 

On the other hand, this does give us less material to wear through and, given the somewhat soft rubber, means that we do expect to see some damage to the outsole after 400-miles of slapping asphalt.

ASICS Gel Nimbus 25 Outsole thickness
Test results
Gel Nimbus 25 2.9 mm
Average 3.2 mm
Compared to 305 running shoes
Number of shoes
0.0 mm
Outsole thickness
6.6 mm

Weight

Despite skimping on outsole rubber as our previous sections demonstrates, the Gel Nimbus 25 still weighs in at a heavier than average 10.2 Oz (289g). This isn’t devastatingly heavy though, and the shoe’s fluffy ride does help make it feel lighter than the scale suggests. 

ASICS Gel Nimbus 25 weight

For a shoe that boasts a similarly large stack yet manages to be surprisingly lightweight, check out the lean, mean, running machine that is the Hoka Rocket X 2

Test results
Gel Nimbus 25 10.19 oz (289g)
Average 9.38 oz (266g)
Compared to 306 running shoes
Number of shoes
5.26 oz (149g)
Weight
12.56 oz (356g)

Cushioning

Heel stack

The Gel Nimbus 25’s stated heel stack of 41.5 mm provided by ASICS puts the shoe beyond the maximum allowable specifications set by World Athletics for competition. However, using our caliper to measure the stack at the point set by that same commission, we found the stack to only be 38 mm high and still within competing range. 

ASICS Gel Nimbus 25 heel stack

Nonetheless the Gel Nimbus 25 isn’t a shoe that’s geared for racing, which makes this huge stack that dwarfs that of the average road shoe purely pleasure over performance. This amount of foam underfoot means that heel strikers can really sink into and savor the midsole cushioning during their daily runs.

Test results
Gel Nimbus 25 38.0 mm
Average 33.7 mm
Compared to 305 running shoes
Number of shoes
7.6 mm
Heel stack
45.7 mm

Forefoot stack

The shoe’s forefoot stack is also significantly taller than our current lab average, with 30.2 mm of foam underfoot. This is also slightly lower than the spec height of 33.5 mm as advertised by ASICS, a strange fact considering we also include the insole in our measurements. 

As a result, forefoot strikers also have plenty of protective foam underfoot to ensure well-dampened landings even during long haul efforts.

ASICS Gel Nimbus 25 Forefoot stack
Test results
Gel Nimbus 25 30.2 mm
Average 25.0 mm
Compared to 305 running shoes
Number of shoes
7.6 mm
Forefoot stack
36.9 mm

Drop

Despite the disparities we found in the shoe’s stack heights, the stated drop of 8 mm remains pretty accurate as the difference in our measurements leave the Gel Nimbus 25 with an accurate offset of 7.8 mm. This mid-level drop is quite versatile and will suit the needs of runners of all experience levels and running styles. 

ASICS Gel Nimbus 25 Drop
Test results
Gel Nimbus 25 7.8 mm
Average 8.7 mm
Compared to 305 running shoes
Number of shoes
-0.8 mm
Drop
16.1 mm

Insole thickness

Even the shoe’s insole is thicker than average, measuring 5.5 mm according to our caliper measurements. This gives us an amply padded and soft surface within the shoe that further contributes to the Gel Nimbus 25’s cloud-like ride. 

ASICS Gel Nimbus 25 Insole thickness
Test results
Gel Nimbus 25 5.5 mm
Average 4.5 mm
Compared to 301 running shoes
Number of shoes
1.5 mm
Insole thickness
7.3 mm

Midsole softness

Note: a low durometer measurement equals a soft material, whereas a high measurement means it's firm.

We pressed our durometer against the Gel Nimbus 25’s midsole to measure how soft it is. With a reading of only 18.6 HA, the Gel Nimbus 25’s midsole is decidedly plush compared to our current lab average. This in combination with the tremendous stack really heightens our sense of perceived cushioning, making the shoe feel extremely comfortable and protective over any distance. 

ASICS Gel Nimbus 25 mid dur

The midsole isn’t overly gummy either. While there is some sinking into the foam as we land, the midsole has a bouncy rebound which provides us with a good level of energy return that is adequate for most daily runs. 

At the same time, the Gel Nimbus is a little too soft to provide that explosive pop that facilitates speedy sessions or helps smash PBs. The Hoka Mach X fits that bill better with its Pebax plate providing a level of responsiveness that offsets its plush dual-density midsole.

Test results
Gel Nimbus 25 18.6 HA
Average 21.4 HA
We use an average of four tests. The photo shows one of those tests.
Compared to 233 running shoes
Number of shoes
8.5 HA
Midsole softness (soft to firm)
41.5 HA

Difference in midsole softness in cold

We placed the Gel Nimbus 25 in our freezer to observe the effect of cold conditions on the shoe’s midsole. After chilling for twenty minutes, we took another durometer reading of the midsole foam and got a post-freezer reading of 25.4 HA. While this is quite a bit stiffer than the room temperature result, it’s still soft enough to provide us with a balanced level of cushioning that will keep our feet feeling comfortable and cared for even through the most bitterly cold winter runs.    

We expect midsole foams to harden in the cold, but becoming 36.3% more firm means that the Gel Nimbus 25 isn’t as consistent as the average road shoe under similar conditions. This means that the difference in the shoe’s ride will be quite apparent for runners living in colder climates. 

ASICS Gel Nimbus 25 Midsole softness in cold
Test results
Gel Nimbus 25 36.3%
Average 25.5%
Compared to 232 running shoes
Number of shoes
0%
Difference in midsole softness in cold
100%

Stability

Lateral stability test

We generally don’t expect much stability from shoes that sit on gargantuan stacks of plush foam like the Gel Nimbus 25. However, this shoe bucks the trend by feeling surprisingly well-planted as we shifted our weight from side to side.

As the following tests will demonstrate; the combination of the shoe’s wide base, rigid build and snug heel counter come together to make the shoe feel reassuringly stable underfoot for neutral runners as well as those with mildly pronating strides.

Torsional rigidity

We faced quite a fair amount of resistance when we bent and twisted the Gel Nimbus 25 in our hands, earning it a score of 4 out of 5 on our subjective scale for torsional rigidity. This isn’t unusual for a shoe with so much foam in the midsole, with the result being a midsole that resists the natural rolling and contortion of our foot during our stride.

This leaves us with a level and stable landing platform with the cushy midsole meaning we don’t have to sacrifice too much in terms of underfoot comfort.

Test results
Gel Nimbus 25 4
Average 3.3
Compared to 284 running shoes
Number of shoes
1
Torsional rigidity
5

Heel counter stiffness

We found the heel counter to be moderately stiff, putting up only a mild amount of resistance to us manually pinching and squeezing at it. This leads us to give the shoe a subjective score of 3 out of 5 for heel counter stiffness. This level of rigidity in the heel counter allows it to snugly hold our foot in place without squeezing in on our Achilles too tightly, allowing for some natural lateral movements. 

Test results
Gel Nimbus 25 3
Average 2.8
Compared to 268 running shoes
Number of shoes
1
Heel counter stiffness
5

Midsole width in the forefoot

The biggest contributor to the Gel Nimbus 25’s stable ride is the fact that the midsole is girthy as well as tall. Measuring 119.4 mm at the forefoot according to our caliper, the shoe’s midsole is much wider than our current lab average. This hefty base made it feel like we were springing off massive clouds during our test runs, with no fear of being caught off balance and plummeting to the ground like Prometheus.  

ASICS Gel Nimbus 25 Midsole width in the forefoot
Test results
Gel Nimbus 25 119.4 mm
Average 113.8 mm
Compared to 306 running shoes
Number of shoes
100.5 mm
Midsole width in the forefoot
126.5 mm

Midsole width in the heel

The shoe’s midsole is similarly substantial at the heel which measures 98.9 mm wide. This gives heel strikers much more of a landing platform than is afforded by the average road shoe aimed at neutral runners. 

ASICS Gel Nimbus 25 Midsole width in the heel
Test results
Gel Nimbus 25 98.9 mm
Average 90.5 mm
Compared to 306 running shoes
Number of shoes
74.9 mm
Midsole width in the heel
106.6 mm

Flexibility

Stiffness

We secured the Gel nimbus 25 to our workbench and used our force gauge to measure the amount of force needed to torque the shoe 90-degrees. With a result of 35.9N, the Gel Nimbus 25 is quite a bit stiffer than our current lab average. 

This is still flexible enough to be considered a comfortable daily trainer. Not to mention the added stiffness gives us a sensation of responsiveness and energy return that was more than welcome during our longer test runs.

Test results
Gel Nimbus 25 35.9N
Average 29.1N
We use an average of four tests. The video shows one of those tests.
Compared to 288 running shoes
Number of shoes
2.2N
Stiffness
94.4N

Difference in stiffness in cold

We also repeated the stiffness test after leaving the shoe in the freezer for twenty minutes, this time to see what effect the cold has on its overall flexibility. 

With a post-freezer requirement of 55.5N to bend the shoe to the desired point, the Gel Nimbus 25 definitely won’t feel as comfortable during the winter or if left outside on a cool evening; with a stiff ride that feels more akin to running in a carbon-plated shoe.

Becoming 54.5% more stiff after our freezer test means that the Gel Nimbus 25 doesn’t perform as consistently as the average road shoe between warm and cold conditions. This means that runners living in countries with significant changes in temperature between seasons will find the shoe much less forgiving on the foot during winter runs. 

Test results
Gel Nimbus 25 54.5%
Average 35.9%
Compared to 288 running shoes
Number of shoes
0%
Difference in stiffness in cold
148%

Grip / Traction

We had no complaints with traction during our test runs in the Gel Nimbus 25, with the tread providing good grip over a variety of surfaces; from asphalt to smooth cobblestones and even dewy grass. 

ASICS Gel Nimbus 25 grip

Size and fit

Toebox width at the widest part

Using our caliper to measure the Gel Nimbus 25 at its widest point, we found it to be narrower than average at 95.6 mm wide. This is quite a snug fit and puts the Gel Nimbus 25 more reminiscent of tight performance shoes than the generous roominess we want from a daily trainer. On the other hand, the combination of a tight toebox and a wide midsole further factors into the Gel Nimbus 25’s stable underfoot sensation as it effectively locks the foot to the shoe’s robust base

ASICS Gel Nimbus 25 toebox

However, with the shoe running a little shoe for its size (260.4 mm vs the average of 265.3 mm for a men’s size 9), runners with wide feet should look into sizing up before abandoning hope on this shoe. 

Failing that, we recommend checking out the also well-cushioned Saucony Triumph 21 with its amply spacious toebox.

Test results
Gel Nimbus 25 95.6 mm
Average 98.4 mm
Compared to 306 running shoes
Number of shoes
89.5 mm
Toebox width at the widest part
109.1 mm

Tongue: gusset type

The Gel Nimbus 25’s tongue is semi-gusseted, with the gusset running down the top half of the tongue. This gave us a solid locked in sensation once laced up, and helped to prevent the tongue from slipping during our test runs. 

ASICS Gel Nimbus 25 Tongue: gusset type
Test results
Gel Nimbus 25 Both sides (semi)

Comfort

Tongue padding

Further contributing to the Gel Nimbus 25’s performance-shoe-feel is its paper-thin tongue, which we measured to be a mere 1.9 mm thick. This is barely any padding compared to the average road shoe, let alone daily trainers, and means that the laces did feel quite apparent over our instep, especially during our longer test runs. 

ASICS Gel Nimbus 25 tongue

While we would have appreciated a little more padding to avoid that annoying lace bite, ASICS does manage to effectively keep some weight off of what is already a heavier than average road shoe. Difficult trade-offs just have to be made sometimes.

Test results
Gel Nimbus 25 1.9 mm
Average 5.6 mm
Compared to 303 running shoes
Number of shoes
0.5 mm
Tongue padding
14.2 mm

Heel tab

The Gel Nimbus 25 features an elegant finger loop at the heel that isn’t just practical in helping us slide the shoe on and off, but looks dang cool too!

ASICS Gel Nimbus 25 Heel tab
Test results
Gel Nimbus 25 Finger loop

Removable insole

The Gel Nimbus 25’s insole isn’t glued in, making replacing it with a custom orthotic possible where necessary. 

Test results
Gel Nimbus 25 Yes

Misc

Reflective elements

Clouds aren’t that visible at night, and neither is the Gel Nimbus 25. With only a small reflective element emblazoning the finger loop of each shoe, we recommend sticking to well-lit routes if running at night without additional high-vis gear. 

ASICS Gel Nimbus 25 Reflective elements
Test results
Gel Nimbus 25 Yes