Hmmmmm... I don't mean to burst anyone's bubble, but if a 25 km climb is 8.3%, it's an average, so it's likely that there are 11, 13, 15% (or more) climbs for a few hundred meters (or more) within the climb...

But : you still rock, no matter how steep or long the climb, by the simple fact that you try it and conqueer it!!