The On Cloudboom Strike 2 goes on sale July 30, 2026 at €250. Five days before the official launch, we break down everything On has reworked: Helion HF foam, a curved carbon Speedboard and a revised CloudTec Sphere geometry. This preview is based on official technical data and the first reactions from the international running press.
On Cloudboom Strike 2 Review: Helion HF, Curved Speedboard, 191 g
8.5/10
The essentials in 3 sentences
The Cloudboom Strike 2 starts from scratch with Helion HF foam that is 15% lighter than the previous generation and a carbon Speedboard with a brand-new curve that releases energy earlier in the stride. At 191 g with a 5 mm drop, it clearly targets the marathon and half marathon for demanding runners chasing energy return and precision. At €250, it joins the super shoe club alongside the Saucony Endorphin Elite 3 and the Puma Deviate NITRO 4, with a snappier, more precise profile.
8.5
/ 10 · RunMorph overall score
Who is it for?Road racers (half marathon, marathon) targeting sub-3:30, comfortable with a 5 mm drop and looking for maximum energy return.
Who should skip it?High-mileage daily training (go for the On Cloudsurfer 2 instead), trail, or runners used to a high drop (8-12 mm).
The Cloudboom Strike 2: On starts from a blank sheet
On Running has always built its reputation on a singular philosophy: where most brands stack millimeters of foam, On bets on geometry and mechanical precision. With the Cloudboom Strike 2, that approach reaches a new level. Due July 30, 2026, it's more than an update of the Cloudboom Strike LS: it's a completely redesigned shoe, from materials to sole geometry.
Its positioning is crystal clear: this is On's premium road racing shoe, built for the marathon and half marathon. It sits alongside the LightSpray version (€310, 158 g), reserved for very fast legs, and speaks to a broader group of competitive runners in the 3-hour to 3:45 marathon range.
RunMorph's advice: if you're training for a marathon with a sub-3:30 goal, the Cloudboom Strike 2 deserves a spot in your race-day rotation. For your regular long runs, stick with a more cushioned shoe like the On Cloudsurfer 2 or the Saucony Triumph 24.
Technical specs
| Feature | Strike 2 standard | Strike 2 LightSpray |
|---|---|---|
| Release | July 30, 2026 | July 30, 2026 |
| Price | €250 | €310 |
| Weight | 191 g | 158 g |
| Drop | 5 mm | 5 mm |
| Foam | Helion HF (new generation) | Helion HF (new generation) |
| Plate | Curved carbon Speedboard | Curved carbon Speedboard |
| Outsole | CloudTec Sphere | CloudTec Sphere |
| Upper | Engineered mesh | Bonded LightSpray jersey |
| Use | Road racing | Road racing |
Helion HF: 15% lighter, same cushioning
The technological core of the Cloudboom Strike 2 is its Helion HF foam. The HF formulation (for High Flow) is a deep overhaul of the original Helion: On claims a 15% weight reduction with equivalent cushioning properties. In practical terms, that means a shoe that weighs less and rebounds faster on every stride.
Helion HF follows the trend of supercritical foams that have dominated the racing segment for several years. It isn't pure PEBA like some rivals, but it shares their key qualities: low weight, responsiveness and better resistance to repeated impacts. On also promises improved compression resistance over the previous generation, which means greater durability for a racing shoe.
Note: the scores in the card above are based on official technical data and the first reactions from the international press. Our real-world test will be published right after the first post-launch runs.
Curved carbon Speedboard: geometry as a propulsion weapon
The carbon Speedboard is On's differentiator in the super shoe world. On the Strike 2, the Swiss brand reworked its geometry with a more pronounced curve under the forefoot. The goal is twofold: release energy earlier in the stride cycle and cut ground contact time. The shoe pitches you forward before your push-off is even finished.
On also claims a stiffer, lighter Speedboard thanks to optimized layering of the carbon fibers. The tuning between Helion HF and the curved Speedboard aims to avoid the excessive bounce sometimes criticized in the most aggressive super shoes: the target ride is snappy yet intuitive, suited to marathon pace as well as intervals.
CloudTec Sphere: an outsole optimized for transition
The CloudTec Sphere outsole is the visual signature of the Cloudboom Strike 2. Its semi-spherical, high-density EVA pods are arranged to maximize ground contact at landing and propulsion at push-off. On the Strike 2, On reworked the layout and density of these pods to complement the dynamics of the curved Speedboard.
The expected result is a smoother heel-to-forefoot transition, with a roll that adapts to your stride rather than imposing one. With a 5 mm drop, the Strike 2 naturally encourages a midfoot strike, a perfect match for competitive marathon and half marathon runners.
Cloudboom Strike 2 vs. the competition
| Model | Price | Weight | Drop | Foam |
|---|---|---|---|---|
| On Cloudboom Strike 2 | €250 | 191 g | 5 mm | Helion HF |
| Saucony Endorphin Elite 3 | €250 | ~185 g | 8 mm | IncrediRUN 40 mm |
| Puma Deviate NITRO 4 | €230 | ~190 g | 8 mm | NITROFOAM Elite |
The main difference: the Strike 2's 5 mm drop, well below most of its rivals (8 mm for the Endorphin Elite 3 and the Deviate NITRO 4). If you naturally land on your forefoot or midfoot, you'll be right in your comfort zone. If you're more of a heel striker, plan a 2 to 3 week adaptation period before racing in it. Also check out our roundup of the best interval shoes of 2026 for an overview of the segment.
Who is the Cloudboom Strike 2 for?
The sub-3:30 marathon racer
The Cloudboom Strike 2 is designed first and foremost for runners who stack speed sessions during the week and races on weekends. Its low weight and responsiveness make it an ideal weapon between 3:30/km and 4:30/km. If your goal is a sub-3:30 marathon or a sub-1:40 half marathon, this shoe is right in your wheelhouse.
The 10 km to half marathon runner
Over shorter distances, the Strike 2 shows its full potential. The energy return of Helion HF combined with the curved Speedboard delivers an almost mechanical sense of acceleration that fans of speed work will love. It works just as well for 5 x 1,000 m sessions as for a 10 km race where every gram counts.
The On runner looking for an accessible super shoe
If you already train in the On Cloudsurfer 2, the Strike 2 is the natural step up for race day. The drop (5 mm) is identical, the On geometry stays familiar, and the transition won't throw you off. It slots neatly into a rotation: Cloudsurfer 2 for daily volume, Strike 2 for performance.
How to fit the Cloudboom Strike 2 into your RunMorph plan
The Cloudboom Strike 2 is not a daily trainer. Its ultra-optimized, performance-first design means you should save it for high-intensity quality sessions and races. Recommended uses:
- Road races: marathon, half marathon, 10 km on asphalt. This is its home turf, where the weight-to-responsiveness ratio makes all the difference.
- Speed sessions: 400 m to 2,000 m intervals, tempo runs at marathon pace. The curved Speedboard's responsiveness makes every footstrike snappier and transitions smoother.
- Long runs late in your build: once or twice in the three weeks before your goal race to get used to the feel, but keep a more cushioned shoe for your regular long runs.
RunMorph plans always separate carbon-plate sessions from easy aerobic runs, to protect your joints and maximize adaptations. If you want a program that smartly integrates the Strike 2 for your level and goal, check out our personalized training plans.
RunMorph verdict: a very promising preview
On paper, the On Cloudboom Strike 2 is very convincing. On takes a distinctive approach: less foam, more geometry. The lighter Helion HF combined with the curved Speedboard promises a snappy, precise and intuitive ride, clearly distinct from its rivals. All in a 191 g, €250 package, in line with the premium super shoe market.
The main watch-out before the real-world test: the 5 mm drop may surprise runners used to 8-10 mm. We'll publish the full real-world review as soon as we've logged the first runs, planned for early August. Early score: 8.5 / 10, based on specs and press reports.
Key takeaways for your training
- Helion HF 15% lighter: On's new-generation foam is lighter at equal cushioning, improving the shoe's responsiveness-to-weight ratio.
- Curved carbon Speedboard: the carbon geometry releases energy earlier in the stride for better-calibrated propulsion than the previous generation.
- 191 g and 5 mm drop: a clear racing profile, worth factoring in if you're used to a higher drop.
- €250 on July 30, 2026: upper-mid range for super shoes, in line with the Saucony Endorphin Elite 3 at the same price.
- Smart rotation: Strike 2 for races and carbon sessions, a more cushioned daily trainer for everyday volume.