Hookless rims and the pressure ceiling
There is no single hookless maximum. The limit falls as your tire gets wider, and the published table runs from 79 psi down to 21 psi across nine width bands.
Find your width, read your ceiling, and then read the note under it — because your own rim and tire can set a lower one.
The limit falls as the tire gets wider
A hookless rim has no lip to hold the bead. It holds by friction and by the shape of the bead seat alone, and the force trying to push the bead off the rim rises with both pressure and tire width. So the wider your tire, the lower the pressure it may be run at — which is the part riders miss, because a single "hookless max" number gets quoted as if it were one figure.
ETRTO maximum inflation pressure, hookless / straight-side rims
| Tire width | Maximum | bar |
|---|---|---|
| up to 24 mm | 79 psi | 5.5 |
| 25–29 mm | 72 psi | 5.0 |
| 30–34 mm | 65 psi | 4.5 |
| 35–39 mm | 58 psi | 4.0 |
| 40–44 mm | 50 psi | 3.5 |
| 45–54 mm | 43 psi | 3.0 |
| 55–64 mm | 36 psi | 2.5 |
| 65–74 mm | 29 psi | 2.0 |
| 75–84 mm | 21 psi | 1.5 |
Maximum inflation pressures for hookless / straight-side rims, as published by Schwalbe and corroborated by ENVE, which names ETRTO as the source and states the same road bands — 72 psi for 25–29 mm and 65 psi for 30–34 mm. Both retrieved 14 September 2026. Converted at 14.5038 psi per bar.
Your rim and tire come first
This table is a ceiling, not a recommendation, and it is not the only one that applies to you. If your rim maker or tire maker publishes a lower maximum than the row above, theirs is the number. Hookless also requires a tubeless-ready tire approved for hookless use — not every tire is, and a tire that is not approved has no safe pressure on that rim at all.
Find out whether the ceiling is anywhere near you
A ceiling only matters if you are near it. Set your width, your weight and the ground you ride, and this shows what the calculator would hand you against what the rim allows — including the case where the two collide.
Close, but under it. You have 3 psi of room before the rim’s limit — near enough that a heavier load or a smoother surface would reach it.
Move the width down into the twenties and put a heavier rider on smooth tarmac and you can watch the clamp engage. Move it back out to gravel widths and it disappears. That is the shape of the whole problem: the limit is real, and for most riders it is nowhere near.
You will probably never reach it
Here is the reassuring part. On the widths most people ride hookless, the pressure you actually want is nowhere near the ceiling. A 40 mm gravel tire at a normal weight lands in the thirties, against a limit of 50 psi. The ceiling is not a constraint on that ride, it is a guard rail well off to one side.
It bites in one place in particular: narrow tires on hookless road wheels. A 28 mm tire under a heavier rider on smooth tarmac can genuinely ask for more than 72 psi, and that is the setup where the limit is doing real work.
The clamp is the last thing that runs
Tell the calculator you are on hookless rims and this ceiling is applied after every other layer — after your weight, your width, your casing, your surface, and after anything your own ride ratings have taught it. Nothing downstream can push the number back up through it.
If your answer comes out at the limit rather than below it, the app says so rather than quietly handing you a capped number. That is worth reading when it happens: it means the pressure you actually want is higher than the rim allows, and the honest fix is a different tire or a different wheel, not a smaller number. The clamp is the last layer the engine runs, which is why nothing downstream can undo it.
If your front and rear differ, the wider one sets it
Running a wider rear than front is common on gravel and normal on a mountain bike. When the two ends differ, the ceiling is taken from the wider tire and applied to both wheels. The wider tire has the lower limit, and one ceiling protecting two wheels has to be the lower of the two or it is protecting neither.