My computer is in for repair so getting hold of my "Favourites" links is a lot of work. I know I have posted a link to a Dutch bikeshop where they have stuff like that.
We have had similar problems with similar racks on big wheel bikes, you need a special rack or loong chainstays to have sucsess with such a bag.
Since you have a BF I would look into the front rack solution they have
http://bikefriday.com/thestore/index...dobL0&cPath=37 You wil not have the same problems carrying it in front as you have now. When loading a 16 or 20" bike I always load the front first and then rear, first of all the racktop in the rear. Search up some older threads about luggage
http://www.bikeforums.net/showthread...teur-rack-ebay