Ghoulardi

I'm in the process of losing weight. I'm currently 6'0 and 255 pounds. I've dropped 27 pounds so far.

I've been riding my heavy tank of a commuter bike, regularly pumping up those tires to as high a PSI as acceptable.

At some point, I'd like to start riding a road bike when not performing utilitarian tasks (though I'll probably still commute on my tank...just want the road bike for longer, faster, fun rides.)

I will probably buy some 20 year old bike from the LBS, nothing new and fancy. At what weight can I expect to be able to do this without being super worried about pinch flats, exploding tubes and spokes flying every which way?

(I plan on eventually getting down to 175-180 pounds.)