The spec sheet promises a 10 mm drop and a weight kept to around 280 grams, the classic pitch for a comfortable stability shoe for your Sunday easy run. Lab measurements tell a different story: a real drop of 7.9 mm and a measured weight of 329 grams. RunMorph cross-checked these figures against field reports to see what the Cloudflyer 5 really delivers.
© On, official photo used for editorial purposes
The On Cloudflyer 5 delivers stability through guidance rather than correction, with a wide, firm heel that frames your stride without an aggressive medial post. Responsiveness takes a back seat: a stiff heel one independent tester called "clunky", and measured energy return below the category average. At a list price of 180 euros for a moderate stack with no premium foam and no plate, the value disappoints next to better-equipped rivals.
On has always sold the Cloudflyer line as its stability option, distinct from the neutral Cloudsurfer and the max-cushion Cloudmonster. The 5th generation keeps that positioning but changes the method: no old-school rigid medial post, but a widened heel platform, a reinforced heel counter and dual-density Helion foam, firmer on the medial side, softer on the lateral side. Independent lab testing backs up this approach: a stability score of 91/100, one of the highest in its comparison, achieved without a classic medial post.
An experienced American tester, who had found the Cloudflyer 4 too heavy and too firm to keep in regular rotation, sees real progress on the 5: a smoother forefoot transition, a better upper and a clearer sense of stability. He still has one clear reservation: the heel stays firm, with a pronounced bevel that makes heel landings a little rough, which he calls "clunky".
RunMorph's advice: if you land squarely on your heel and mainly want guidance without excessive restriction, this firm heel shouldn't bother you. If your foot strike drifts toward the midfoot or forefoot during a run, as one independent tester noticed on his own runs, the ride can get harsher as the kilometers pile up.
© On, official photo used for editorial purposes
The official spec sheet and French retailers list a weight between 275 and 285 grams and a 10 mm drop. Independent lab measurements tell a clearly different story, itself backed by a separate independent weigh-in of 300 grams on a US size 9.
| Data point | Claimed | Measured (lab) | Gap |
|---|---|---|---|
| Weight (standard men's size) | 275 to 285 g | 329 g | +44 to 54 g (up to +19%) |
| Drop | 10 mm | 7.9 mm | -2.1 mm (-21%) |
| Heel / forefoot stack | 31 / 21 mm | 33.2 / 25.3 mm | in line at the forefoot, the heel is closer to 33 mm than 31 mm |
In practice, the Cloudflyer 5 is neither as light nor as steep as its spec sheet suggests. A real drop under 8 mm pushes the shoe toward a more neutral transition profile, even though it's marketed as a high-drop benchmark for heel strikers. This double gap isn't documented anywhere in the brand's official communication.
| Spec | Value |
|---|---|
| Category | Moderate-stability daily trainer (guidance, no medial post) |
| Measured weight (men's) | 329 g (11.6 oz) |
| Measured drop | 7.9 mm |
| Measured stack (heel / forefoot) | 33.2 mm / 25.3 mm |
| Midsole firmness (HA scale) | 28.0 HA (firmer than the category average, 20.1 HA) |
| Heel energy return | 48.3% (category average 58.7%) |
| Heel shock absorption | 108 SA (category average 131 SA) |
| Wet traction | 0.41 (category average 0.53) |
| Breathability | 4 / 5 |
| Measured outsole wear | 0.8 mm (category average 1.1 mm, so better wear resistance) |
| Overall independent lab score | 78 / 100 (Daily 83, Tempo 40, Race 28, Stability 91) |
| List price | 180 euros (seen from 118 euros at some retailers in October 2026) |
This is the core profile On is targeting. Camille Cholbi, the French tester at 21Run, describes a shoe that's comfortable from the first kilometers, with cushioning that feels natural once you're rolling, and a real sense of stability on long runs.
The lab scores leave no doubt: 83/100 for daily use against 40/100 for tempo and just 28/100 for racing. The Cloudflyer 5 isn't meant for intervals or a threshold session.
A wide, well-padded upper and a thick gusseted tongue that keeps the laces from biting: both field tests we read agree on a generous, comfortable fit, at the cost of a weight that stays high for the category.
RunMorph read 3 independent sources on this exact model in full, on top of the independent lab report used for the measurements and the overall score: the French field test from 21Run (Camille Cholbi, daily runs plus a long run the day after a 25 km session), a detailed review by an American tester (run-and-walk protocol, direct comparison with the Cloudflyer 4), and the aggregated page from Runnea (numeric sub-scores across 10 criteria).
All three sources agree on stability and fit comfort: 21Run calls it a "very pleasant" shoe over several runs, the American tester gives it an A- for stability and fit, and Runnea shows a stability sub-score of 7/10 and a cushioning sub-score of 9/10. Where they split is heel firmness: 21Run doesn't raise it as an explicit criticism, while the American tester clearly calls it the shoe's central flaw, with a performance grade capped at C+. RunMorph flags this split rather than smoothing it over: it most likely depends on your foot strike and on the distance of the run tested.
The number is clear: 48.3% heel energy return in lab testing, against an average of 58.7% for the daily trainers compared. Combined with firmer-than-average foam (28.0 HA vs 20.1 HA), it confirms the American tester's impression: a heel that absorbs less than it could, felt as "clunky" on hard landings. The lab's Tempo (40/100) and Race (28/100) scores point to the same limit: this shoe doesn't come alive beyond easy pace.
A 180-euro list price for a moderate stack (33.2 mm at the heel), with no premium foam and no plate, puts the Cloudflyer 5 above the average price of its category on the US market (170 dollars against a 157-dollar average). The B- value grade from the American tester reflects this gap between price and technical performance, even if stability and outsole durability remain solid.
© On, official photo used for editorial purposes
Both shoes come from the same On range but serve different needs: the Cloudsurfer 2, already reviewed by RunMorph, is a versatile neutral daily trainer, while the Cloudflyer 5 fully owns its stability positioning.
| Criterion | Cloudflyer 5 | Cloudsurfer 2 |
|---|---|---|
| Positioning | Stability daily trainer (guidance) | Versatile neutral daily trainer |
| Measured weight | 329 g | Lighter, neutral profile with less material |
| Drop | 7.9 mm measured (10 mm claimed) | CloudTec Phase profile without Speedboard |
| Ideal use | Easy runs and long runs, heel strike | Daily runs at any pace, neutral stride |
For a neutral runner looking for versatility, the Cloudsurfer 2 remains RunMorph's On benchmark. For a runner who needs real heel guidance, the Cloudflyer 5 is still the brand's only stability option.
| Criterion | On Cloudflyer 5 | Brooks Adrenaline GTS 25 | Asics Gel-Kayano 33 |
|---|---|---|---|
| Measured weight | 329 g | 295 g | Lighter thanks to the dual FF Blast foam |
| Stability (method) | Platform-based guidance, no medial post | GuideRails, external guidance | |
| List price | 180 euros | 160 euros | Equivalent premium positioning |
| Responsiveness | Low (lab Tempo score 40/100) | Decent for a comfort stability shoe | Boosted by the dual FF Blast foam |
At 295 g measured for 160 euros, the Brooks Adrenaline GTS 25 does better on weight for the money. For a bigger budget but clearly more responsiveness, the Asics Gel-Kayano 33 remains the premium stability benchmark in the RunMorph catalog.
Based on the list price (180 euros) and an estimated lifespan of 500 to 550 km for a stability daily trainer at this level (a reasoned estimate, not measured over a pair's full life by the sources we read), the cost per kilometer comes to around 0.33 to 0.36 euro. That's well above the Kiprun Cushion 500 (0.07 euro/km) and above the Brooks Ghost 18 (0.19 euro/km), two daily trainers already reviewed by RunMorph, which confirms the price gap identified above.
© On, official photo used for editorial purposes
The Cloudflyer 5 belongs on easy runs and Sunday long runs, where stability and fit comfort matter more than responsiveness. In a structured plan, it isn't built for tempo or interval sessions, where its lab score drops sharply. To organize your paces across a full training cycle and know when to bring out a livelier pair, the RunMorph training plans lay out, zone by zone, the sessions where a stability daily trainer like this one fits.
The On Cloudflyer 5 keeps a real promise of guidance-based stability, confirmed by both lab testing and the field reports read for this article. But two gaps weigh on the verdict: a measured weight far from the claim, and responsiveness that tops out early, consistent with below-average energy return for its category. Add a high price for what it delivers, and it ends up reserved for a specific use: easy runs and long runs for heel strikers. 7.8/10: the score rewards stability and durability, not responsiveness or value.
© On, official photo used for editorial purposes