The V3 & WiFi framesets have 70mm clearance between the chainstays, so a 29x2.25" tyre is the biggest we can recommend in combination with the 60mm mudguards!
Without mudguards it is possible to fit a 29x2.35" tyre (depending on tread pattern) but the clearances are tight, so expect some tyre buzz.
To play it safe, just stick to 29x2.15" tyres like the factory spec Schwalbe Big Ben Plus.
