First I have to say, bikeforums gets neater everytime I log on... I mean... how cool is it to find a forum dedicated to 200lb+ cyclists?!
I started riding BMX (freestyle) when I was about 12 or so and stopped around 17 years old. In my 20's I got heavily (pun intended) into competetive bodybuilding where my competetive weight was 185lbs with 4% bodyfat and my "offseason" weight was about 205-210.
I've pretty much been into motorcycles (on and off road and racing) for the last 10 years and gave up bodybuilding some time ago. The wife and I still workout heavily in the gym and we do about +/-100 miles per week; myself on a track bike/fixed gear. I still ride freestyle BMX on a 20" bike (yes, I look like a bear on a unicycle!).
At my current weigth of 230lbs at 5'9" - I'm stocky and broad like Mike Tyson. I feel leaner, faster, quicker, and more agile as I ever did. I can skip rope like a boxer, blast hills on my fixed gear and ride flatland BMX sessions on my 20" for hours on end where most of it is spent rolling and balancing on one wheel at a time standing on footpegs (I got back into BMX about 6 months ago and it all came back!).
It looks like any serious weigh won't be coming off - but maybe getting down to a solid 210/215 is good (I actually have a six pack at that weight).
I'm stoked to have found this forum, because there really isn't much for the serious cyclists that don't have "the look" of a cyclist. I really wish they'd make cycling clothing that fit folks like us, though