ORIGINAL: cartercg
Wheel spats are tiny and will not accept a normal 55mm wheel. I opened them up with a dremel . The one on the left has been modified. Not the greatest spats I've seen but they should be fine.
I agree, the Oxai spats are tiny. I don't know what others are using for wheels, but I had a set of light foam wheels from Aircraft-world where the hub was thin enough to fit without having to open up the spat hole. Mounting the wheel in the drill press and getting stuck up the foam with a sanding board got the wheel diameter and profile to the right size. They've seen two years of trouble free duty flying off grass, but I don't know if you can buy them anymore?