Originally Posted by
Cadillac
I suggest you try a 3-wheel recumbent such as a Catrike. It will be much easier on your knees and can easily accommodate your weight. Also, sitting in the "cradle" of the Catrike will be much easier on you than a DF (diamond frame) bicycle with its relatively narrow seat. As well, the sitting position in a Catrike is better for your back.
I think this is sound advice. I have a neighbor who's back is one large fusion. Four years ago he gave up his "bike" for a recumbent trike. He now rides 15,000 miles per year, singing all the way. Another friend bought a custom trike from a local manufacturer three years ago and is now in the best shape of his life. He's 58 and hadn't exercised since high school.
Good luck. There are lots of good times waiting for you on whatever bike you ride.