I am placing this in a new thread so as not to perpetuate the one that predictably devolved into internecine squabbling. My observations are based on the recollection that this story of stolen bicycles caused a similar kerfuffle on the forum that preceded this one.
I am fairly sure that Mark Roland was correct when he postulated that the Rivendells were kept at the Carter residence in Plains and the story of replaced and stolen bicycles at the Carter Center in Atlanta was unrelated. Unfortunately the linked article from January, 2009, included a photo of President Carter on his Riv. That photo has been separately identified as being taken in Plains. In addition, a google search brings up a short youtube video of President Carter arriving in downtown Plains on his Riv.
Based on his health issues, I doubt that President Carter has ridden any bicycle in some time. I have no idea where his Rivendells are now, but based on his track record I would guess that they have been passed on in a responsible and meaningful way.
I had hoped someone with more first hand knowledge and/or research skills would set the record straight, but since that has not happened I decided to share my observations. If they are inaccurate, I will be happy to be corrected.
David