On Cloudboom Strike
£260
UK RRP
Midsole to scale · mm · red dashes mark the 40mm road limit
- Weight
- 210 g
- men's US 9
- Stack
- 39.5 / 35.5 mm
- heel / forefoot · drawn above, against the 40mm line
- Drop
- 4 mm
- Plate
- carbon fibre
- Foam
- Helion HF
- Stability
- balanced
- Competitive life
- ~250 km
- before the foam stops giving it back
- Built for
- Half · Marathon
Verdict
A genuinely competitive marathon racer and the first On shoe that belongs in this conversation on merit.
■ Caution
Narrow through the midfoot even by racing shoe standards. Expensive for what it is against the Adios Pro 4.
Straight answers
- Is the On Cloudboom Strike legal for road racing?
- Yes. The On Cloudboom Strike measures 39.5mm at its highest point, 0.5mm inside the World Athletics 40mm road limit. The limit only binds Applicable Competitions; most club and local races apply no shoe rule at all.
- How much does the On Cloudboom Strike weigh?
- 210g in a men's US 9 (UK 8), by the manufacturer's stated figure. Weight moves roughly 3.5% per UK size step, so a UK 11 weighs materially more than the spec sheet says.
- What is the stack height and drop of the On Cloudboom Strike?
- 39.5mm at the heel and 35.5mm at the forefoot — a 4mm drop. A carbon-fibre plate runs through Helion HF.
- How long does the On Cloudboom Strike last?
- We estimate roughly 250km of competitive life — the point at which the foam has degraded enough that you are no longer getting the benefit you paid £260 for, not the point at which the shoe falls apart. Spread over race cycles, that is what the cost-per-race figure on this page is built from.
- Is the On Cloudboom Strike good for a marathon?
- Yes — the marathon is one of the distances it is built for (half marathon and marathon). A genuinely competitive marathon racer and the first On shoe that belongs in this conversation on merit.
Legality by event
Cloudboom Strike at 39.5mm · every panel drawn to one scale
Road racing
40mm · 0.5 clear
Track events
20mm · 19.5 over
Field events
20mm · 19.5 over
Cross country (spiked shoes)
20mm · 19.5 over
Cross country (non-spiked)
40mm · 0.5 clear
Race walking
40mm · 0.5 clear
Mountain and trail
no limit
Drawn from the manufacturer’s stated stack height, which is not the measurement World Athletics takes — the rule is measured on a men’s US 8.5 sample, and larger sizes may legally exceed it. An indication, not a ruling. Limits bind Applicable Competitions; most club and local races apply no shoe rule at all. What that means in practice.
Reading — what would the Cloudboom Strike save you?
Time bought back
−2:32 – 3:53
Off 3:45:00, that lands you at 3:41:07 on the optimistic end.
- Per race
- £66
- ~3.9 races in the foam
- Per second
- £0.34
- whole-life basis
- Sticker
- £260
- UK recommended retail
Economy gain 3–4.2% v. a traditional flat, adjusted for pace and your current shoes. Full method.
Manufacturer-stated specs unless marked estimated · last reviewed 2026-09-04 · prices are UK RRP; check the retailer for the live figure.