Thanks Gareth, your help is truly appreciated.
I'm thinking of putting some additional supports up from where the rack would bolt on near the rear axle, something like this......
..... sorry for the VERY crude drawing
I got the idea from looking at this picture......
....... of a "Heavy Duty" trailer hitch from >>
Tony's Trailers <<
I think this would really make things solid, but it might make using the rear rack impossible...... Then again, I could always use the Cannondale with the rear rack if I need to make a run without the trailer...