I have a solution for you but there's no way to convert a class I receiver to a class II and definitely not to a class III. You are in luck though there is a custom fit hitch available for your Coachman Cross Trail Motorhome. It is the Curt RV Bumper 2" Trailer Hitch Receiver item # E-100. This hitch bolts directly to your 4" square channel bumper. It has a 2" receiver and boasts a 350 lbs tongue weight capacity.
I recommend verifying that your bike rack is rated to be used behind a motorhome... view full answer...