You said: "The Hadiths are legal rulings based on the Koran."
Sorry, that is wrong. They are simply what Mohammed has stated and done and have nothing to do with the Koran itself. Let me quote the Muslims directly:
"These reports are known as Hadiths (meaning statements, but often called Traditions in English). They have been handed down to us from the Companions, the Muslims who lived at the time of the Prophet."
"Actually, a Hadith might be a report of what the Prophet (peace and blessings be upon him) said, did, or what he approved or disapproved of. The collection of the deeds, practices, and words of the Prophetknown from the Hadithsis known as the Sunnah, and it forms the second source of Islamic Law after the Quran."
http://www.islam-online.net/English/introducingislam/Prophet/Said/article01.shtml
See my link @ #202.