Quote Originally Posted by ggh View Post
I don't really know much about this, so I have a a question. If you have to use a heavier weight line (e.g., a 6 weight line on a 5 weight rod) so that fast rod will perform better, isn't what you really have done is transform the fast rod into a slower action rod--which maybe a lot of us would find better to start with? Or am I missing something (as I often do)? Just asking......
Changing to a heavier or lighter line does not change the action of a rod. Rod action is an inherent physical property of the rod.

It may change how you perceive the action. Same as of you put a line on the rod and change the amount of line outside the rod tip.

If put a 5wt line on a 5wt rod, strip of 30 ft of line and cast it, the road will bend and unbend (load/unload) a certain amount. Strip off 35ft and it will bend more. Only 25 ft it will bend less.

Now put a 6wt line on the same rod. You will find that 25 ft of a 6wt will feel about the same as 30 ft of the 5 wt line. The action has not changed. You have just used a shorter length of a heavier line to provide the same load as a longer length of a lighter line.

Changing lines doesn't change a rod or make it better or worse. It may make it better or worse for you though, which is good enough reason to experiment.