Originally Posted by
jakepounder
QUOTE=milkbaby;14817394]There's not going to be a big difference in performance in my opinion -- I have 105, Ultegra, and Red on my bikes and they all work great if you know how to set them up properly. You should try to ride each groupset and decide based on hood ergonomics and shifting feel. Some people are very sensitive to the shape of the hoods, d that can make a big difference in which you prefer. Also, some people prefer either STI or Doubletap shifting, so that is the other main criteria to consider, but explaining it won't help you decide because you gotta try it first hand to find out exactly how they feel and work. There is a weight difference, but that really isn't very important performance-wise.
What's the difference between sti and double tap?
Thanks. I am a bigger rider. And actually the main reason I'm going with the caad is because of the frames stiffness and weight. It only weighs 1150 grams. But i didn't understand what you meant from the fautigue part. Are you saying that bigger riders will get fatigued less quickly or the other way around?[/QUOTE]
stiffness can affect fatigue because the stiffer a frame is the more it translates road vibration and bumps to the rider. Over time, feeling this vibration can wear you out quite a bit. That is the biggest advantage that carbon fiber frames have over aluminum, that they tend to dampen road noise a bit.
this doesn't affect larger riders as much as smaller ones.
that being said, a stiffer frame also translates more of your body motion to directly powering the bike. It's all a system of compromises.