Hooked or hookless gravel wheels: approved tyres, the 5-bar road cap and when a tube is allowed
On a hookless rim the tyre decides as much as the wheel. Schwalbe allows only its TLE and TLR tubeless tyres on hookless rims, gives the ETRTO road cap of 5 bar even when the sidewall allows more, and notes that many rim makers ask for tyres of at least 28 mm. Whether you may fit a tube differs by maker: Schwalbe allows tubes inside TLE/TLR tyres on hookless rims, Zipp only with an approved tyre and within the rim's pressure limit.
Schwalbe's hookless guidance, read on 5 November 2026, says hookless rims have a straight inner sidewall and usually a wider rim, that only its TLE and TLR tyres may be fitted, and that the rim maker's tyre widths, especially the minimum width, must be respected; many rim makers recommend at least 28 mm. The 5-bar ETRTO cap it cites is for road bikes, and Continental's road tyres show the cap falling further as width rises, to 58 psi at 35 mm in our Road tires reference. So the exact pairing of rim and tyre model, width and pressure is what needs the approval, not the word tubeless. When rim, tyre and standard give different limits, the lowest applies; none is a recommended riding pressure.
A tube does not change tyre retention
Schwalbe says its TLE and TLR tyres can be ridden with inner tubes as well as tubeless on hookless rims. Zipp is stricter: it allows a tube on its hookless rims only with an approved tyre and within the rim pressure limit. An emergency tube belongs in your repair plan only when both your tyre maker and your wheel maker allow it.
Check availability of a second suitable tyre
For a GRARO build, first satisfy frame clearance and intended terrain, then the wheel/tyre approval. Find an available replacement tyre and save its exact size. If your preferred winter or travel tyre is excluded, include that limitation in the decision.
