On Cloudboom Strike 2 review
On’s carbon-plated marathon racer, rebuilt around a lighter Helion HF foam and new CloudTec Sphere channels in place of the classic open pods.
- Drop
- 5 mm
- Heel stack
- 40 mm
- Forefoot
- 35 mm
- Weight
- 191 g
- Support
- Neutral
- Plate
- Carbon
Our verdict
Calm, stable speed for the long haul.
The Cloudboom Strike 2 pairs a bouncy PEBA-based foam and a stiff carbon Speedboard with a broad forefoot that reviewers find unusually steady for a super shoe. It suits half and full marathon runners who land on the midfoot or forefoot and want control more than an aggressive push, while heel strikers and 5K racers have better matches.
Strong points
- Unusually stable for a carbon racer, thanks to a broad forefoot platform
- Strong energy return and cushioning for long distances in RTINGS’s lab
- Light: 191 g in a men’s US 9 by the brand figure
- True to size for nearly every tester
- Near full-length rubber that held up well over 72 km of hard running
Weak points
- Narrow, soft heel that RTINGS rates poorly for heel strikers
- Less snappy than the fastest super shoes at 5K and 10K pace
- Stiff, unpadded heel counter that pressed on one tester’s Achilles
- No wide version listed
Who it fits
- You land on the midfoot or forefoot
- You race the half or the marathon
- Super shoes usually feel wobbly to you
- You want one carbon shoe for workouts and race day
Who should skip it
- You land hard on your heel
- You want the most aggressive 5K and 10K racer
- Your Achilles is sensitive at the heel tab
Shoe profile
Where the Cloudboom Strike 2 sits among the 395 shoes in our catalogue, and what changed from the Cloudboom Strike.
| Axis | Cloudboom Strike 2 | Cloudboom Strike | Change |
|---|---|---|---|
| Cushioning | 64 | 83 | −19 |
| Lightness | 94 | 88 | +6 |
| Stability | 30 | 30 | = |
| Drop | 9 | 6 | +3 |
| Response | 60 | 100 | −40 |
Fig. 1 · How to read it. Each axis runs from 0 at the centre to 100 at the edge. Cushioning, lightness and drop are the shoe’s rank in the catalogue from listed figures; stability and response are scored from the support type, the plate, the rocker and the intended use. The dotted grey line is the catalogue median. Source: Strideprint catalogue (cat).
Where it sits in the catalogue
Weight191 g, lighter than 93% of shoes
Drop5 mm, lower than 80% of shoes
Heel stack40 mm, higher than 64% of shoes
Forefoot stack35 mm, higher than 79% of shoes
How it feels
Written from 7 published tests. We quote measurements, not impressions we did not have.
Bouncy PEBA, firmness up for debate. Helion HF PEBA foam split by CloudTec Sphere channels on a 40 mm heel: soft and bouncy for some testers, firmer than most racers for others.
Steady up front, narrow at the back. Broad, steady forefoot that testers rate unusually stable, but RTINGS measured a narrow, soft heel that suits heel strikers poorly.
Efficient rather than explosive. High energy return in RTINGS’s lab, but a late rocker and stiff plate make it efficient at marathon effort rather than punchy at 5K pace.
Bouncy PEBA, firmness up for debate. The midsole is Helion HF, a PEBA-based foam that Black Toe Running reports is about 15% lighter than before, split into three sections by the new CloudTec Sphere channels. Doctors of Running and Believe in the Run list 40 mm at the heel and 35 mm at the forefoot, a heel that 57 of the 207 neutral road shoes in our catalogue exceed.
RTINGS rates the cushioning at 8.8 out of 10, among the strengths of the shoe, and Believe in the Run describe it as soft and bouncy. Marathon Sports and The Run Testers found it firmer than many racers. Running Warehouse publishes impact absorption of 80 to 82% at the heel from Heeluxe lab testing.
Steady up front, narrow at the back. This is the trait reviewers notice most. Believe in the Run found the wide forefoot platform more stable than any of its rivals, and The Run Testers rate it more controlled than most carbon racers. Doctors of Running describe a neutral shoe with mild guidance from flared forefoot edges and a central line.
The heel is the exception. RTINGS measured a very narrow, soft heel, scores stability at 4.7 out of 10, and calls it much less suitable for heel strikers. If you land on the midfoot or forefoot, the broad front does the work; if you land far back on the heel, it does not.
Efficient rather than explosive. RTINGS scores energy return at 8.7 out of 10 at both heel and forefoot, and Running Warehouse publishes 73 to 76% energy return from Heeluxe testing. The curved carbon Speedboard is stiff from front to back, with a forefoot rocker that Doctors of Running found arrives late.
That makes it efficient at marathon effort rather than punchy. Doctors of Running found it sluggish at efforts faster than 10K pace, Believe in the Run wanted more bite at toe-off, and Marathon Sports noted a flatter rocker than more curved racers.
Read more
Bouncy PEBA, firmness up for debate. The midsole is Helion HF, a PEBA-based foam that Black Toe Running reports is about 15% lighter than before, split into three sections by the new CloudTec Sphere channels. Doctors of Running and Believe in the Run list 40 mm at the heel and 35 mm at the forefoot, a heel that 57 of the 207 neutral road shoes in our catalogue exceed.
RTINGS rates the cushioning at 8.8 out of 10, among the strengths of the shoe, and Believe in the Run describe it as soft and bouncy. Marathon Sports and The Run Testers found it firmer than many racers. Running Warehouse publishes impact absorption of 80 to 82% at the heel from Heeluxe lab testing.
Steady up front, narrow at the back. This is the trait reviewers notice most. Believe in the Run found the wide forefoot platform more stable than any of its rivals, and The Run Testers rate it more controlled than most carbon racers. Doctors of Running describe a neutral shoe with mild guidance from flared forefoot edges and a central line.
The heel is the exception. RTINGS measured a very narrow, soft heel, scores stability at 4.7 out of 10, and calls it much less suitable for heel strikers. If you land on the midfoot or forefoot, the broad front does the work; if you land far back on the heel, it does not.
Efficient rather than explosive. RTINGS scores energy return at 8.7 out of 10 at both heel and forefoot, and Running Warehouse publishes 73 to 76% energy return from Heeluxe testing. The curved carbon Speedboard is stiff from front to back, with a forefoot rocker that Doctors of Running found arrives late.
That makes it efficient at marathon effort rather than punchy. Doctors of Running found it sluggish at efforts faster than 10K pace, Believe in the Run wanted more bite at toe-off, and Marathon Sports noted a flatter rocker than more curved racers.
Which runs it’s for
| Run | Fit | Why | Source |
|---|---|---|---|
| Marathon race | Made for it | Its main job: RTINGS rate marathon racing as its strongest use, and The Run Testers keep it for longer events. | RTINGS, The Run Testers |
| Half marathon race | Made for it | Doctors of Running found it at its best around 10K to half marathon effort. | Doctors of Running, RTINGS |
| Tempo | Made for it | Tempo and threshold work suit the stiff plate and steady platform. | Doctors of Running, Black Toe Running |
| Intervals | Can do | Marathon Sports liked it for speed sessions; Doctors of Running found short, fast reps sluggish. | Doctors of Running, Marathon Sports |
| Long runs | Can do | Fine for long runs with faster segments. RTINGS rate long runs a step below racing. | RTINGS, Marathon Sports |
| Easy runs | Not for it | RTINGS find the plate and stiff build poorly suited to easy paces. | RTINGS |
| Walking | Not for it | Doctors of Running do not recommend it for walking or standing. | Doctors of Running |
Source: RTINGS, The Run Testers, Doctors of Running, Black Toe Running, Marathon Sports
What the tests say
Published reviews agree the Cloudboom Strike 2 is a stable, comfortable, true-to-size marathon racer and a big change from the first Strike. They differ on toe room, on how soft it feels, and on how quick it is at short distances.
| Test | Type | Our reading | In one sentence | Source |
|---|---|---|---|---|
| Doctors of Running | Review | Mixed | Doctors of Running grade it B overall: a fine half and marathon racer with a wide forefoot, held back by a stiff heel counter and a sluggish feel at short-race pace. | Read |
| RTINGS | Lab | Positive | RTINGS score it 8.2 out of 10 for half and full marathon racing, praising energy return and cushioning while flagging the narrow heel. | Read |
| Believe in the Run | Review | Positive | Believe in the Run give B grades across the board and call it a solid, stable race-day option, while wishing for more bite at toe-off. | Read |
| The Run Testers | Review | Positive | The Run Testers see a balanced, durable, approachable carbon shoe, better for longer events than for pure speed. | Read |
They agree
- Stable for a super shoeBelieve in the Run, The Run Testers and Marathon Sports all credit the broad platform with a controlled ride that most carbon racers lack.
- Built for long racesRTINGS, Doctors of Running and The Run Testers all point it at the half and full marathon rather than short races.
- True to sizeDoctors of Running, RTINGS, Believe in the Run and Black Toe Running all found the length right in their usual size.
- A clear step up from version 1Doctors of Running call it a different shoe from the original, and Believe in the Run a large improvement on its predecessor.
They split
- Roomy or snug up frontDoctors of Running and Black Toe Running found a wide, roomy toe box for a racer. The Run Testers found it tighter than other On shoes and suggest half a size up for more room, and RTINGS warns the front may feel short once feet swell late in a marathon.
- Soft or firmBelieve in the Run describe a soft, bouncy ride and RTINGS rate the cushioning highly. Marathon Sports found it firm underfoot, and The Run Testers less soft than many racers.
- Stable at the heel too?Three reviews praise its stability, but RTINGS scores stability low because of the narrow, soft heel. The two views fit together: the forefoot is broad, the heel is not.
How it’s built
A dual-density Helion HF midsole split by CloudTec Sphere channels, a curved carbon Speedboard, an open-weave upper and near full-length rubber.
Two densities of Helion HF PEBA foam split by CloudTec Sphere channels, a curved carbon Speedboard, an open-weave upper and near full-length rubber that wears well.
| # | Part | Measure |
|---|---|---|
| 1 | UpperOpen-weave mesh | – |
| 2 | Tongue | – |
| 3 | Heel | – |
| 4 | MidsoleHelion HF and CloudTec Sphere | 40 / 35 mm |
| 5 | PlateSpeedboard | – |
| 6 | Insole | – |
| 7 | Outsole | – |
Fig. 3 · Side profile. Stack heights to scale (listed: 40 mm heel, 35 mm forefoot); the split between the two foams is not measured and is drawn at mid-height. Dashed: insole, hidden. Sources: Doctors of Running, Believe in the Run, Running Warehouse, RTINGS, Black Toe Running, Marathon Sports, i-run, The Run Testers.
Upper. A thin, see-through open weave that Doctors of Running and Believe in the Run found breathable and secure. Doctors of Running found it scratchy against bare skin and recommend socks.
Tongue. Thin and minimal. Doctors of Running describe it as gusseted and found the lockdown secure, while RTINGS lists it as ungusseted and harder to lock down.
Heel. More structure and padding at the collar than on the first Strike, per Black Toe Running. Doctors of Running found the counter stiff and unpadded, with a padded tab pressing on the Achilles.
Midsole. Two densities of Helion HF, a PEBA-based foam, cut by two channels into three sections that compress and rebound where you land. The channels replace On’s large open pods.
Plate. A curved carbon plate, lighter and stiffer than on version 1 according to Believe in the Run and Black Toe Running. Doctors of Running found it very stiff through the midfoot and forefoot.
Insole. Removable and made of the same Helion HF foam, adding cushioning underfoot, per RTINGS and Marathon Sports.
Outsole. Nanotube rubber over almost the full length, more coverage than most racers according to The Run Testers. i-run lists it for dry and wet roads.
Read more
A dual-density Helion HF midsole split by CloudTec Sphere channels, a curved carbon Speedboard, an open-weave upper and near full-length rubber.
1. Upper. A thin, see-through open weave that Doctors of Running and Believe in the Run found breathable and secure. Doctors of Running found it scratchy against bare skin and recommend socks.
2. Tongue. Thin and minimal. Doctors of Running describe it as gusseted and found the lockdown secure, while RTINGS lists it as ungusseted and harder to lock down.
3. Heel. More structure and padding at the collar than on the first Strike, per Black Toe Running. Doctors of Running found the counter stiff and unpadded, with a padded tab pressing on the Achilles.
4. Midsole. Two densities of Helion HF, a PEBA-based foam, cut by two channels into three sections that compress and rebound where you land. The channels replace On’s large open pods.
5. Plate. A curved carbon plate, lighter and stiffer than on version 1 according to Believe in the Run and Black Toe Running. Doctors of Running found it very stiff through the midfoot and forefoot.
6. Insole. Removable and made of the same Helion HF foam, adding cushioning underfoot, per RTINGS and Marathon Sports.
7. Outsole. Nanotube rubber over almost the full length, more coverage than most racers according to The Run Testers. i-run lists it for dry and wet roads.
Durability. Better than most race shoes. Doctors of Running saw no visible outsole wear after 72 km of hard running, and The Run Testers credit the thick rubber for using it in training as well. One i-run customer reports a broken plate after two runs, a single report that no reviewer echoes.
Durability. Better than most race shoes. Doctors of Running saw no visible outsole wear after 72 km of hard running, and The Run Testers credit the thick rubber for using it in training as well. One i-run customer reports a broken plate after two runs, a single report that no reviewer echoes.
Specs, listed and measured
Every figure carries its source.
Weight (men’s), g
Heel stack, mm
Forefoot stack, mm
Drop, mm
| Spec | Listed | Measured |
|---|---|---|
| Drop |
|
|
| Heel stack |
|
|
| Forefoot stack |
| – |
| Weight, US M9 |
|
|
| Support |
| – |
| Plate |
| – |
| Surface |
| – |
| Release year |
| – |
Fig. 4 · Listed vs measured. Bars start at zero. Sources: Black Toe Running, Running Warehouse, Doctors of Running, RTINGS, i-run.
Sizing and fit
Take your usual size; check toe room if your feet swell or splay on long runs.
Length
True to size
Widths
standard
Toe room
Wide for a racer according to Doctors of Running and Front Runner, who note room for toe splay with a snug midfoot. The Run Testers found less space than in other On models.
Doctors of Running, The Run Testers, Front Runner
Full sizing notes from testers
Doctors of Running, RTINGS, Believe in the Run, Black Toe Running and Front Runner all found the length right in their usual size. RTINGS rates the fit at 9.7 out of 10 for accuracy.
Toe room divides testers. Doctors of Running and Black Toe Running describe a wide, anatomical toe box for a racer, while The Run Testers found it tighter than other On shoes and suggest half a size up for more room. RTINGS adds that the front can feel short as feet swell late in a marathon.
The shoe is sold in unisex sizes. Marathon Sports advises women to go about 1.5 sizes up from their women’s size. RTINGS lists no wide version.
Doctors of Running, RTINGS, Believe in the Run, The Run Testers, Marathon Sports, Black Toe Running, Front Runner
Vs Cloudboom Strike
A full redesign rather than a refresh: new midsole geometry, lighter foam, a new plate and a roomier, more forgiving fit.
| Cloudboom Strike 2 | Cloudboom Strike | |
|---|---|---|
| Support | Neutral | Neutral |
| Drop | 5 mm | 4 mm |
| Heel stack | 40 mm | 43 mm |
| Forefoot | 35 mm | 39 mm |
| Weight | 191 g | 210 g |
Reviewers rate version 2 better almost across the board. Keep the original only if you specifically liked its fit or its lower 4 mm drop; for comfort and stability over a full marathon, version 2 is the one they recommend.
Listed figures. Source: Strideprint catalogue (cat).
Version history: Cloudboom Strike to Cloudboom Strike 2
CloudTec Sphere replaces the open pods. Two channels split the midsole into three sections instead of On’s classic open pods. (Marathon Sports, Black Toe Running, Front Runner)
Lighter foam and plate. Helion HF is about 15% lighter, and the curved Speedboard is lighter and stiffer. Marathon Sports report 6.7 oz against 7.4 oz, about 190 g against 210 g. (Believe in the Run, Marathon Sports, Black Toe Running)
Roomier, more comfortable fit. Doctors of Running found a wider toe box, and Black Toe Running more heel padding and better forefoot lockdown. (Doctors of Running, Black Toe Running)
One more millimetre of drop. Black Toe Running report a 5 mm drop against 4 mm on the original. (Black Toe Running)
Tougher outsole. Doctors of Running found the outsole more durable than on version 1. (Doctors of Running)
Alternatives compared
Each one fixes one thing the Cloudboom Strike 2 does not do.
| On Cloudboom Strike 2 |  ASICS Metaspeed Sky Tokyo |  Saucony Endorphin Elite 3 |  Puma Deviate Nitro Elite 4 |  Hoka Cielo X1 3.0 | |
|---|---|---|---|---|---|
| Pick it for | This page | Faster | Softer | Lighter | More cushion |
| Drop | 5 mm | 5 mm | 8 mm | 8 mm | 7 mm |
| Heel stack | 40 mm | 39.5 mm | 39.5 mm | 38 mm | 48 mm |
| Weight | 191 g | 170 g | 207 g | 170 g | 198 g |
| Support | Neutral | Neutral | Neutral | Neutral | Neutral |
Questions runners ask
Does the On Cloudboom Strike 2 fit true to size?
Yes for length. Doctors of Running, RTINGS, Believe in the Run and Black Toe Running all ran in their usual size. Toe room is the open question: The Run Testers found it tighter than other On shoes and suggest half a size up for more room, while Doctors of Running found the toe box wide for a racer.
Cloudboom Strike or Cloudboom Strike 2: what changed?
Almost everything. The Cloudboom Strike 2 swaps the open pods for CloudTec Sphere channels, uses a Helion HF foam about 15% lighter, gets a lighter and stiffer plate, a wider toe box and more heel padding. Marathon Sports report it at about 190 g against 210 g, and the drop goes from 4 to 5 mm.
Is the Cloudboom Strike 2 good for heel strikers?
Not really. RTINGS measured a very narrow, soft heel that gives little support at first contact and calls the Cloudboom Strike 2 much less suitable for heel strikers. Its stability comes from the broad forefoot, which works best if you land on the midfoot or forefoot.
Is the Cloudboom Strike 2 good for a marathon?
That is what it is built for. RTINGS rate half and full marathon racing as its strongest use, and The Run Testers keep it for longer events. Reviewers value its stability and durable rubber over 42 km; runners chasing the most aggressive push may prefer a faster racer.
How much does the Cloudboom Strike 2 weigh?
The brand figure is 191 g for a men’s US 9, per Black Toe Running. Independent scales read a little higher in the same size: 198 g at Running Warehouse and 199.6 g at RTINGS. On 191 g, it ranks 14th lightest of the 170 neutral road shoes weighed in that size in our catalogue.
Can I train in the Cloudboom Strike 2?
For workouts, yes. Marathon Sports used it for uptempo runs and long runs, and The Run Testers credit its thick rubber for training use. For easy days, RTINGS find the carbon plate and stiff build poorly suited, so keep a daily trainer for recovery runs.
Sources
- Doctors of Running, On Cloudboom Strike 2 Review (Matt Klein, July 2026). Accessed Oct 13, 2026.
- RTINGS, On Cloudboom Strike 2 review. Accessed Oct 13, 2026.
- Believe in the Run, On Cloudboom Strike 2 Review. Accessed Oct 13, 2026.
- The Run Testers, On Cloudboom Strike 2 Review. Accessed Oct 13, 2026.
- Marathon Sports, On Cloudboom Strike 2 Review. Accessed Oct 13, 2026.
- Black Toe Running, On Cloudboom Strike 2 Review. Accessed Oct 13, 2026.
- Running Warehouse, On Cloudboom Strike 2, Unisex. Accessed Oct 13, 2026.
- i-run, On-Running Cloudboom Strike 2. Accessed Oct 13, 2026.
- Front Runner, On Cloudboom Strike 2. Accessed Oct 13, 2026.
- Strideprint, Strideprint running shoe catalogue (ranks computed on 2026-10-13). Accessed Oct 13, 2026.
- on.com · Drop, Weight, US M9, Support, Plate, and Release year, listed
- cat: Strideprint catalogue, 395 shoes
How we review. We read published tests, brand and retailer pages and lab measurements, cross-check the figures and flag where they disagree. We did not test this shoe ourselves. Last updated October 13, 2026.