On Wed, 08 Nov 2006 20:59:00 +0200, Jarmo Hurri
wrote:


Robert He used an example that if one held a fly rod rod truly
Robert horiz., and gave the handle a very quick upward (I think he
Robert means backwards; toward ones head) pure rotation, the tip
Robert momentarily goes Downward.

Robert Does it ?

According to Don Phillips' "The Technology of Fly Rods" (page 87), yes
it does. He says that he demonstrates this by having someone hold a
piece of paper rear of the stroke direction and then initiating a cast
with a rapid pulse (it does not have to be up, sideways will do as
well). If you are interested in this, I think it is relatively easy to
make a convincing experiment to confirm this.

Phillips also says that this phenomenon has practical importance: if
you initiate a cast too quickly, it will cause slack.

Robert Why does it, if so ?

I have some guesses, but since I am not a physicist I will pass and
leave this issue to be resolved by someone more educated.

Ok, I just happened to have a 9' 3wt Winston standing up behind my desk, and
next to my glass collection it's the slowest rod I own (even my 2 weights are
faster). I put it together, stood at one end of my office with the rod held
reasonably horizontally, with the tip lined up with a detail feature on a
closet door. Once the rod was steady I gave it a quick wrist-flip to rotate
the rod, while observing the tip.

Whoa! The tip dropped close to a foot before heading upward!
Yikes! How totally non-intuitive, I couldn't have been more wrong.

/daytripper (head-scratching time...)