Originally Posted by
BigAura
I'll stand by statement that the racks on carbon-racing bikes is a bad idea. That "handling getting more squirrelly than it'd be otherwise" is going to result in stresses to the frame that the designer's never intended. It's not that carbon isn't strong, its that the designers are using it for it's lightness to make it better for "racing".
The problem that I observed wasn't flexing, it was how off balance everything got due to the bike being so light. Keep in mind that I also abused the living crap out of those bikes and they only died due to me crashing one too many times.