In case anyone is wondering, a Triban RC520 road bike will clear mudguards/fenders and 700x38 slicks (albeit the monumental toe overlap). Here is mine, all ready for fall/winter. : r/bicycling
Help a Beginner Upgrade his Triban RC 520 into a lighter Gravelbike : r /gravelcycling
Triban's new RC500 and RC520 are UK-friendly and surprisingly cheap - BikeRadar