Normand,
Out of curosity I weighed the first 30 feet of the fly line that comes with the Sage Smallmouth Bass rod and it weighed 1/32nd of an inch past 280 which is what a 10wt is suppose to weigh according to the scale. Since it went past the 280 mark just a little, I have to assume the first 30 feet is 290. According to my scale a 11wt line is suppose to weigh in at 330. The rod is marked as 290. Unfortunately, I do not have any 10wt line to compare the 2 lines to see if there is any difference between the 2 when layed side by side. This probably does not answer your question, but, I have always wanted to weigh the first 30 feet and your post gave me the initiative to do it, so, thanks.
Warren
Fly fishing and fly tying are two things that I do, and when I am doing them, they are the only 2 things I think about. They clear my mind.