In a message dated 97-10-22 05:11:56 EDT, you write:

> Hello everybody from Spain. I have recently joined the Rodmakers, and I
>  will be very grateful if  somebody could give me some information about
>  Stress curves.

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I posted this last month, but with all the questions popping up
about stress curves, I decided to repost it. If everyone agrees
with my analysis, perhaps we should put it on the Web Page?
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In it's most basic use a stress curve shows you how close
a split cane rod is to breaking with the weight and length
of line you specified. Garrison believed 200,000 ounces
per square inch was a good, safe upper level. In reality 
you can go up to 220,000 or 230,000 without any problems. 
Garrison himself went up to 220,000 on his lighter rods.
Garrison believed that below the 140,000 point the bamboo 
stopped flexing.

As you get deeper into stress curves you can begin to pick out certain
characteristics that tell you what kind of action the rod has, or will have

if it hasn't been made yet. A Garrison rod, which I consider to be slow, 
has a well rounded "hump" near the tip and a fairly slow drop off as it 
goes towards the handle. Let's see if I can do this with ASCII art.

|
|             *  *  
|          *           *     *
|         *                        *     *
|        *                                        *      * 
|       *                                                         *    * 
|      *
|     *
|    *
|   *
|  *
_*______________________________________________


The rod that I'm always raving about, the Cattanach 7' 0"
4 wt, I consider to be fairly fast. It has a stress curve like this:

|
|             *    
|          *     *
|         *          *   
|        *                 *  
|       *                       *   
|      *                              *                     *
|     *                                      *    *    *          *  *   *
|    *
|   *
|  *
_*______________________________________________


The blip near the handle is the Cattanach hinge, and it greatly 
enhances roll casting. Don't forget to  put it in. I did and the rod 
I made was a terrible roll caster. It isn't as necessary on longer 
rods, but on shorter rods it's definitely needed.

A Paul Young Para 15, what is described as a parabolic action 
looks like this:

|
|             *  *                             *  *
|          *         *                       *        *
|         *             *                 *            *
|        *                  *           *                *
|       *                        *  *                       *
|      *
|     *
|    *
|   *
|  *
_*______________________________________________
 

Looking at this rod, and never having cast one, I would guess 
that it would feel fairly slow, due to the enhanced bending near 
the handle, but able to throw a lot of line, due to the stiff mid 
section. I would also guess that it could roll cast really well.

There are as many variations of stress curves as there are 
rodmakers. This covers the slow, fast and parabolic actions. 

Darryl Hayashida

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