The 01 to late model 04 have a frame issue still ongoing today. The frame tubing behind the passange floorboard cracks. The nature of this frame issue is that all is fine today, but next week, next month, the frame could be cracked....so frame inspections prove nothing but that the frame isn't cracked yet. Trailer pulling is not the cause of these frame cracks. I have read about just as many failures from owners who don't pull trailers.
There is no recall from Honda on this issue...in fact Honda isn't saying a word to anybody about this problem and most dealers are clueless as well.
Honda changed the frame design in late 04 to correct this problem. There have been no frame problems of any kind that I have read about with the redesigned 05 and up frame.
I would not buy a 01 to 04 model unless the frame has been replaced by Honda with the newer spec frame from the 05 and up models...otherwise it's best to just buy a 05 and up model....not worth taking the risk with the affected models and having to deal with Honda over a cracked frame with a bike out of warranty...IMO
Honda has so far been replacing cracked frames out of warranty, but who knows how long Honda will continue to do this with the affected 01 to 04 model
Here is a picture of a 01 to 04 model with a cracked frame. This is a 03 model with 35K miles. This is on the right side of the frame behind the passanger floorboard looking up from under the bike.
Here is the same spot of the frame looking from the outside of the bike.....right side of the bike.
Here is a 05 frame after Honda redesigned the weak area of the frame.