|Peter... Each and every fly rod/line standard, listed in the AFFTA or AFTMA classes is based on the DT line, and that sets the rating, and the casting performance. If it didn't there would be one hell of a mess. And since a DT line is heavier than the rating there is an optimum load for each rod and with 5# it happens to be 210gns. The rating is 140gns, and that's the weight of the first 30' of the line.|
And if you use a WF line 30' head you SHOULD upline the rod by at least 2 weights. That's "because" of the casting weight difference between a DT line and a WF line with a 30' head, which is still rated at the AFFTA standard.
Its pretty simple stuff really, and false casting is designed to get the right load on the rod by velocity/load change, from the rated weight to the optimum load over time.
This change from the rated weight, like the 5#, 120gns to the optimum load, 210gns, is really the GDE, the Grain Delivery Envelope. Which relates to ALL types of lines.
And bear in mind that 210gns is the bottom of the 8# GDE, which is 210/315gns.
But if you put the proper load on the rod, the optimum load, you can cast it just as well and as far with only one or maybe two backcasts. Is the way fishing is done, since most fishes don't wait for anglers to flip/flop a fly line around the ocean.
Me I'm only interested in fishing, not casting, but I'm also interested in truth in whatever we are about.