so i notice that when i ride a stepthru or "girls bike" there is a certain amount of frame flex, especially if its an older cruiser, like my early 60's hawthorne (or my WIFE'S hawthorne). the frame is solid, but at my 215lbs, sometimes it is a little unsettling. is some amount of frame flex normal for earlier "girls bikes"? i checked everything out and its all straight, but i do notice a little, as on my early 80's clairidge "girls bike". i figured that simply by design, they are not as ridgid as a conventional frame. just wondering, thanks.