Originally Posted by
AlexanderLS
At this point you should just focus on dieting/power walking. Maybe some hiking.
At your current weight, you should be able to enjoy a good amount of food and still lose weight. I've never weighed quite that much but when I was at about 280 the weight came off really fast with just mild dieting. If you need some help you could use FatSecret or a similar website designed to help you track calories and set goals.
Alexander, Given that the guy has had PTs and medical doctors, and maybe even a registered dietician, who are 1) trained and experienced in medicine, 2) legally licensed to give medical advice and care, and 3) familiar with the OP's medical history and have the advantage of a physical exam of the OP, are you REALLY suggesting you know better? Are you really willing to give medical advice? Sheesh.
To the OP: A bike has the advantage of cardiovascular and resistance training without total weight-bearing, which is why I suspect your docs and PTs suggested it. I would recommend a steel-framed bike with 36 spokes/wheel minimum (as others have suggested). Probably a mountain or cross bike. If you find a couple you like, call the mfr's customer service line and explain your situation and ask if the bike has a weight limit and if they would suggest that bike as their best selection.
The latest and greatest gearings are 11spd rear cog, but the chains and cogs aren't as thick as perhaps some vintange 8,9, or 10 speeds. Save your money for now, and buy that 14lb CF racing bike when you're down to 180. I'd avoid fancy suspension - a solid "diamond" (standard bike setup) frame, and no shocks on the front.
Good luck.