Loop size relative to Speed up and stop
It's said that "loop size depends on how far the rod tip travels during the speed up and stop (SUAS)". Yet the seeming lack of a clear definition of SUAS begs a few questions in my mind.
Do we begin speeding-up at the beginning of the stroke or only at the end?
When does the SUAS begin and when did the rest of the casting stroke end (leading up to it)?
I teach loop size differently in a manner more consistent with the way Bruce Richards describes it. The size of the loop is a result of where the rod stops relative to the path of acceleration, which must be straight.
Therefore if a line is tight end to end and accelerating forward, where the leading device (rod tip) stops defines how large the gap will be between the upper and lower leg of the loop.
So even if a rod was 100ft long as long as it's deflection tracks a striaght path and stops close to the path, the loop will be tight.
If the rod deflects the line away from the path, well... that's a technique problem. I do however agree that in most cases it's more difficult to maintain the deflection to path with a longer rod, but that is the fault of the caster and in skilled hands not significant in the 11ft to 15ft length differential we are discussing here.
If someone has a horizontal final snap motion, which (like you) is the way I interpret the SUAS, then the loop will not be opened in a downward deflection. If fact it's kind of a 'cheat' I use to keep loops very tight with a two-hander. I use the metaphor throwing a frisbee on a stick to describe it.
Conversely, even if someone doesn't really speed-up at the end of the stroke the loop can be opened up dramatically by dropping the rod tip with a constant rate of acceleration (smooth). In fact many trout casts use final accelerations and rod positions to make the line go in every which way even opposite the rod direction (reach casts, aerial snap mends, etc).
The snap-t reverses the tension and the final SUAS is directly opposite the line's direction. Clearly it's the rods position relative to the line's path that defines the size of the snap shape.
In digging deeply into this topic, which I believe a good instructor would do, I find it harder to accept the SUAS mantra. It has the merit of simplicity, however it suffers from lack of clarity. I don't find the following difficult to say or understand, and believe it is more accurate:
The size of the loop is a result of where the rod stops relative to the path of acceleration, which must be straight.
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