The On Cloudboom Max is a race shoe worth buying for people running a full in 4 to 4:30 on race day. What decides it: the 40mm heel and 8mm drop. The Japan official also writes "for those aiming for sub-4:30 in a full marathon." It weighs 296g, and is the only one of On's 3 race shoes whose support is "stability."
The Shoe Nerd's top pick
If you run a full in 4 to 4:30 and buy an On race shoe, buy the Max, not the light Strike 2. The plate is not carbon but a resin with 8% fiberglass. On writes that it supports people who land on the heel and lets them run comfortably up to 4:30. The 105g weight is an understandable price for that build.
Key points
- Stack is 40mm at the heel and 32mm at the forefoot. The number is in On's announcement
- As a per-km pace, 4 hours is 5:41 and 4:30 is 6:23. On's target is this range
- Dividing the Japan price by the dollar price, the Max ($1) is about JPY 124, and the Strike 2 about JPY 141
Who is the Cloudboom Max for? A shoe with the target time on its product page
The Cloudboom Max is a buy for runners running a full in 4 to 4:30, as a race-day shoe. What decides it: a 40mm heel and an 8mm drop.
Product pages for race shoes usually write only "for people who want to run fast." The Max is different. On's announcement writes its own target: "serious marathon runners aiming to finish in 4 to 4:30."
This article reads this one shoe by official numbers only. A table of race and training shoes by target time is in the article on shoes by marathon target time.
Cloudboom Max weight and stack? The official numbers
| Item | Official numbers | Source |
|---|---|---|
| Release date | Aug 21, 2025 | On announcement |
| Price | JPY 28,600 (incl. tax) | Official Japan site |
| US price | $230 | On announcement |
| Weight | Men's 296g / women's 250g (one shoe) | Japan official, On announcement |
| Stack height | Heel 40mm / forefoot 32mm | On announcement |
| Drop | 8mm | Japan official, On announcement |
| Width | One (listed as “Regular”) | Official Japan site |
| Sizes (men's) | 25.0–31.5cm (14 sizes) | Official Japan site |
| Colors (men's) | 1 color (White | Black) | Official Japan site |
| Plate | Yes (Speedboard blended with fiberglass) | Official Japan site |
On's launch announcement gave the stack as 40mm heel, 32mm forefoot, 8mm drop. The subtraction checks out (40 − 32 = 8).
The foam is 2 layers of Helion HF, a material On advertises as "ultralight hyperfoam." It says the shape of the upper and lower layers was tuned to fit the running form of non-elite runners.
The support field is "stability." In On's explanation, it is the category with a good balance of stability and comfort for people who want confidence in running. The Japan official intro says "for the first marathon and for chasing a time too."
Image: Rakuten Ichiba
On Cloudboom Max
Lowest price on Rakuten is JPY 19,999 (as of 10/13), ranging up to JPY 28,600 depending on the shop. Prices change daily. Shoes are best tried on in the evening, when your feet swell, with your usual socks. Fit varies by brand, so check the return and exchange terms on the shop page before you buy.
RecommendedSee it on Super Sports XEBIOSee it on Rakuten IchibaSee it on Yahoo! Shopping Japanvs the original Strike: what changed from the previous generation
The Cloudboom Max is a new name born in 2025 and has no previous generation. On's announcement also says it "joins the Cloudboom family."
So I compare it with the 2024 original Cloudboom Strike, the starting point of On's marathon race shoes. What do you add and subtract from an elite shoe to make one for a 4:30 runner? Lined up from On's own materials.
| Item | Original Strike (2024) | Max (2025) | Difference |
|---|---|---|---|
| Weight | 210g | 296g | +86g |
| Heel stack | 39.5mm | 40mm | +0.5mm |
| Forefoot stack | 35.5mm | 32mm | −3.5mm |
| Drop | 4mm | 8mm | +4mm |
| US price | $280 | $230 | −$50 |
What is interesting is that the heel thickness differs by only 0.5mm (40 − 39.5). What changed is the forefoot, 3.5mm thinner (35.5 − 32). As a result the drop doubles from 4mm to 8mm (8 ÷ 4).
In other words, the Max is not a "thinner, cheaper version" of an elite shoe. It keeps the heel height, lowers the front, and tilts from heel forward. The shape matches On writing in the plate's explanation that it "supports people who land on the heel."
Weight is up 86g (296 − 210), about 41% (86 ÷ 210). Price is down $50 (280 − 230), about 18% (50 ÷ 280). Heavier, cheaper and tilted: that is the rework for a 4:30 runner.
How it differs from the Cloudboom Strike 2 and Volt
There are 3 laced Cloudbooms currently. Lined up by Japan official numbers.
Scroll the table sideways →
| Model | Weight | Drop | Plate material | Support |
|---|---|---|---|---|
| Cloudboom Max | 296g | 8mm | With glass fiber | Stability |
| Cloudboom Volt | 210g | 5mm | With carbon fiber | Neutral |
| Cloudboom Strike 2 | 191g | 5mm | With carbon fiber | Neutral |
The plate material differs
Of the 3, only the Max has a non-carbon plate. In On's announcement it is a polyamide (a nylon-family resin) blended with 8% fiberglass. The purpose is to support people who land on the heel and keep comfort for marathons up to about 4:30.
As On explains, the plate's job is to flex at the forefoot to store force and release it at toe-off. How stiff a plate suits you changes with running speed and landing. Dropping the carbon was to suit people up to about 4:30.
Turning the weight gap into the full distance
The gap to the Strike 2 is 105g (296 − 191), and to the Volt 86g (296 − 210). At a 1m stride, a full marathon is 42,195 steps, about 21,100 per foot. The gap to the Volt is 86g × 21,100 = about 1,815kg.
That is not a small number. 4:30 is a 6:23-per-km pace (270 min ÷ 42.195km) and 4 hours is 5:41 (240 min ÷ 42.195km). For people who run 4 hours or more at that speed, the numbers show the call to take tilt, stability and thickness before lightness.
- Full-marathon goal of 4 to 4:30. You land on the heel → Cloudboom Max
- Race day is 10km to the half. Also use it for fast training → Cloudboom Volt
- Aiming for well under 4 hours in a full → Cloudboom Strike 2 (Strike 2 article)
Image: Rakuten Ichiba
On Cloudboom Volt
Lowest price on Rakuten is JPY 26,400 (as of 10/13), ranging up to JPY 50,800 depending on the shop. Prices change daily. Shoes are best tried on in the evening, when your feet swell, with your usual socks. Fit varies by brand, so check the return and exchange terms on the shop page before you buy.
RecommendedSee it on Super Sports XEBIOSee it on Rakuten IchibaSee it on Yahoo! Shopping JapanWhat I like
The 1st is that it writes its target runner in numbers. Writing "sub-4:30" means faster runners stop buying. Knowing that, they made one race shoe for 4 to 4:30 runners, and that is the part I buy most.
The 2nd is the 40mm heel. On writes in another shoe's announcement that the limit usable in races is 40mm. The Max stacks foam right up to that limit and takes landing impact with thickness.
The 3rd is that the foam has the same name as the upper models. Helion HF is the high-rebound foam On uses for race shoes, and the Max uses it in 2 layers. They changed the plate material but did not lower the foam's rank.
The 4th is that the foot-wrap build suits long hours. The Japan official feature field lists "ankle pad that makes long-distance running comfortable" and "upper that fits flexibly with foot movement." On's announcement also writes that the upper is built to conform to the foot over long hours.
The 5th is how the price lands in Japan. Dividing the Japan price by the dollar price, the Max is about JPY 124 per dollar (28,600 ÷ 230) and the Strike 2 about JPY 141 (35,200 ÷ 250). Even among On race shoes, the Max converts cheaper in Japan.
Things to watch
The biggest is the 296g weight. It is on the heavy side among On's road shoes, only 15g from the stability Cloudrunner 3 (311g) (311 − 296). It is not a shoe to buy thinking "it's a race shoe, so it's light."
Point 2 is the few colors. The Japan official men's listing of Oct 13, 2026 had only 1 colors. The Strike 2 has 4.
The 3rd is the single width. The support field says "stability," but no wide version is out.
The 4th is that the use is worded loosely. The Japan official description says "the ideal pair for marathon training," while On's announcement says "performance on race day," so it is not settled whether it is for training or racing. Since the announcement calls the Cloudboom "a family of race-day shoes," I read it as a race-day shoe.
The 5th is that it costs more than a training shoe. Choosing a plateless daily shoe and racing in it is a perfectly workable choice at a 4:30 pace. Nothing in the official numbers says only this shoe will get you there.
Who is it for?
- Full marathon goal of 4 to 4:30
- You land on the heel. You are used to shoes with about an 8mm drop
- Want a separate pair with thickness and stability for race day
If you choose by lightness, the Strike 2, 105g lighter; if race day is up to the half, the Volt fits better. If your current training shoes already carry you through races, you have time to wear them out first.
Price and where to buy
| Shoe | Official price | Per gram | Rakuten price range |
|---|---|---|---|
| Cloudboom Max | JPY 28,600 | About JPY 97 | JPY 19,999–28,600 |
| Cloudboom Volt | JPY 26,400 | About JPY 126 | JPY 26,400–50,800 |
| Cloudboom Strike 2 | JPY 35,200 | About JPY 184 | — |
Per gram, the Max is the lowest of the 3. On's race shoes put a price on the weight they cut. The Max's price pays for the thickness, plate and stability build, not lightness.
The Japan official product page says that within 30 days of purchase, unused items can be returned with no shipping charge. There is only 1 color, but if you are unsure of size, buying from the official site lets you try again.
On Rakuten shops, colors and model numbers not on the official site sometimes appear. Choose after checking that the product name is "Cloudboom Max," not the Volt or Strike.
Image: Rakuten Ichiba
On Cloudboom Max
Lowest price on Rakuten is JPY 19,999 (as of 10/13), ranging up to JPY 28,600 depending on the shop. Prices change daily. Shoes are best tried on in the evening, when your feet swell, with your usual socks. Fit varies by brand, so check the return and exchange terms on the shop page before you buy.
RecommendedSee it on Super Sports XEBIOSee it on Rakuten IchibaSee it on Yahoo! Shopping JapanFAQ
How does the Cloudboom Max fit?
Choose the size on the same label as your usual shoes. The Japan official "Size and fit" field says "Regular. True to size," and On's announcement says "fits true to size." Men's run 25.0–31.5cm in 0.5cm steps, in one width.
How does the Cloudboom Max differ from the Strike 2?
Weight and plate material. The Max is 296g with a fiberglass-blended plate; the Strike 2 is 191g with a carbon fiber-blended plate. For 4 to 4:30, the Max; for well under 4 hours, the Strike 2, in line with the official split.
Can sub-4 and sub-5 runners use the Cloudboom Max?
Sub-4 runners are in the target. On's announcement names "4 hours to 4:30," and exactly 4 hours falls within that range. The stability rating and 40mm heel also apply to runners who are out on the course longer, like 5-hour runners.
Can the Cloudboom Max's 40mm heel be used in races?
It is exactly the limit On writes. On states in another shoe's announcement that the limit usable in races is 40mm, and the Max's heel is 40mm in the announcement's numbers. If you enter races where certified records matter, the rules section of the entry guide decides how it is treated.
