Good morning to all who read this post. yesterday i posted my thoughts on the spiral wrap and can say that i seem to have struck up a what seems to be a hot topic within certain circles in the rod building community ive been reading the posts and can safely say i opened pandoras box with my post.now ive been recieving Toms magazine for sometime now and have learned quite alot from each issue. i am currently designing my latest project still only on paper but its a rewrap of an old spinning rod that i have its an old fenwick hmg-908 fast taper rod and was debaiting whether or not to try a spiral wrap but after reading all the posts this morning ive decided to go ahead and try a simple spiral for myself. thanks to all who replied to my post it was both interesting and informative i will post pictures once i figure out how. thanks again. Alex

Emory,

What you say is true, but the larger diameter also creates greater resistance to twist. (A larger diameter does not guarantee that you'll have thinner walls - these two are not automatically related. An offshore rod with a large diameter also has very thick walls.) The additional force by the slightly greater moment arm is not linear in respect to the additional resistance to twisting that moving in diameter provides. This is why lighter bass and other freshwater and light saltwater rods generally exhibit actual twist more than heavy rods, even though the heavier rods are carrying far greater loads.


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Tom,
You are right that the relationship between wall thickness and diameter is not linear. Both the power and the hoop strength will increase roughly directly with increased wall thickness but the power will increase roughly at the 4th power of diameter, doubling the diameter will result in 16 times the power. So a small increase or decrease in diameter will require a much larger increase or decrease in wall thickness to maintain the same power in the blank. The increase in torque is roughly directly proportional to diameter because the moment arm is increasing directly with the increase in radius.
However, in some circumstances the torque created by a spiral wrap can actually be higher than the torque created by a conventionally wrapped rod because of where the line tends to ride in the guides. With a conventionally wrapped rod the line tends to ride at the bottom of the guides closest to the blank while with a spiral wrap it tends to ride in the guides at a point farther from the blank which means that the moment arm is longer therefore the torque is higher. But in either case, spiral or conventional, when the line is in the same plane as the center of the blank there is no moment arm so there is no torque.

Jim:

Sunject: Responce to Jims "Would have show up better if?"

My pic was not specifically designed to support any particual aspect of the spiral wrap but merely to show the line path moreover how the neutral 180 degree guide is in fact not carring a load even with the rod blank flexed deeply. (which might have shown up better froma side shot if that were my intent) Furthermore, the path traveled is fairly straight even when flexed and as the name of the guide inducates "Bumper" the guide produces more of a bump in an otherwise straight line path, where as, a rod employing a spiral wrap that has a series of guides between the top guide and the 180 degree guide, are said to be "Transition" guides slowing transitioning the line from the top of the rod to the botom. On the simple spiral the Bumpers guide is a mere speed bump in the otherwise straight line path of the line

Emory,

The torque will never be higher with a spiral wrapped rod because the line will always ride in the bottom of the guide. If the fish swims off to the side the angler is just going to turn a few degrees and then the fish is below or directly off the rod tip again, and the line is back in the bottom of the guide.

It's useless to try and infer that anyone is ever going to have to battle more torque with a spiral wrapped rod than with a conventionally wrapped rod - it won't happen. With the spiral wrapped rod you can relax your grip and the reel will always stay in a position where you can use it. With the conventionally wrapped type, you relax your grip and the reel is going to wind up somewhere under the rod. Argue torque all you want, but with a spiral wrapped rod the angler will exert far less effort in subduing a fish and his reel will always remain upright. Not so with a conventionally wrapped rod. This is the fact of the matter under actual fishing situations.

If you experience any torque with a spiral wrapped rod, just relax your grip and the rod will turn a few degrees and torque will disappear - but the reel will still be where you can comfortably use it. Try that with a conventionally wrapped rod sometime.


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Edited 1 time(s). Last edit at 01/30/2007 11:39AM by Tom Kirkman.

I love these conversations between Tom and Emory... I learn so much!

Regards......Doug@
TCRds

Tom,
I agree that the fisherman can ALMOST always turn so that the rod is pointing at the load in which case with either a conventionally wrapped or a spiral wrapped rod there will be no torque. However, I will say again that if the load is at an angle to the rod the torque will actually be higher with a spiral wrap than with a conventionally wrapped rod because the line will be farther from the center of the blank and therefore the moment arm will be longer.
I do not believe that the issue of spiral wrapped versus conventionally wrapped rods is black and white. I think that there are some situations where the spiral wrapped rods have significant advantages over conventionally wrapped and also situations where conventionally wrapped rods have advantages over spiral wrapped rods.

Chris Karp Wrote:
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> reduces torque totally but there is a neutral area
> that has to have the load bridged by the blank to
> the load bearing bookending guides. The 1st bottom
> 180 degree guide is neutral carring no load even
> when the blank is heavily flexed as depicted, note
> the line coming in contact with the 1st 180 degree
> botom guide at the 9:00 o'clock position, This
> means the blank supports the load for a double
> space between the 1st stripper gude on top of the
> rod and the 2nd180 degree guide on the bottom of
> the rod.
>

Chris,,,, if that bumper wasn't there, bet it would be more toward 6 than 9 on the 180 and it would be carrying more load. At least that's what my rod has been telling me for a few weeks as I have been playing with the options and positioning. That's exactly what has me playing with rub rails now. Letting the line go where it wants and as close to the blank as possoble, because flex in that transition zone causes optimal bumper position to change and every MM of bumper height contributes to more indirection in how the line carries on the 0 and first 180 guides.