Petite trouvaille rigolote: je voulais voir la différence entre ma config et les recommandations d’un tableau comme celui partagé ici:
Et comme je ne connais pas l’ETRTO du Dirt Wizard par coeur, j’ai fini chez Surly pour le trouver.
Je suis tombé sur un fichier d’instructions générale (https://surlybikes.com/cdn/shop/files/80-001542_INST.pdf?v=16469442113454319732) qui indiquait des correspondances pneus/jantes et de la marge minimum à la fourche:
Citation
The Information below is a guidline as you look to pair Surly tires with the appropriate rim.
Narrow Touring/Gravel (41mm)—Designed for use with rims 23–30mm wide
Wide Touring/Gravel (2.3–2.7")—Designed for use with rims 25–50mm wide
Plus tires (2.7–3.0")—Designed for use with rims 35–65mm wide
Fat tires (3.7–4.3")—Designed for use with rims 50–100mm wide
Fatter tires (4.5–4.8")—Designed for use with rims 65–100mm wide
Fattest tires (6.0–6.2") are designed for use with 90–100mm wide rims
When you mount a new tire or inspect your bike, look for the actual clearance between the rotating wheel and tire and all
parts of the frame and fork. Only use a tire that provides enough clearance — when considering lateral rim flex, frame flex,
and a wheel or rim that may be out-of-true. Surly recommends no less than 6mm tire clearance for bikes designated as off-
road and above.
Donc en théorie, ça passerai même avec la jante KH XC tant que j’ai au moins 6mm de marge pneu/fourche (selon les critères vélo… 
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