Arrggghhh! mega assumption !
Apples to apples if you please. A fit rider that is 200lbs will greatly exceed a fit rider at 140. Every study I have read supports the fact that bigger riders put out more watts. Magnus Baksted comes to mind. Ask how many frames the guy broke last year. A big rider may or may not go faster on those hills but he will be putin out the watts regardless. Weight limits are needed and I would like to see the same thing done with frames and forks. The needs of a very big or small rider are not met when all the info you get from the bike company it that X frame is now 10% lighter and 13% stiffer and other useless stuff without any real comparison. With a weight limit I can assume that the bike was designed for a guy my size (big, small or average). Also how many bike owners have a way to measure power? Not the best way to market safety if 85% of your target buyers do not know what they produce as a peak power. We should also consider the fit heavy weight rider sprinting at 1200 watts plus will loose more power to the flex in a ti spindle as compared to a cromo that offsets the gain made by the slightly lighter wieght of the ti spindle. Again the same with frames and forks. So my point is that if you are over the wieght limit you are in most cases better served by the cromo spindles unless your a real dog in the power dept. But then why do you want a ti spindle?