SPG 720/780 Taper Question

Re: SPG 720/780 Taper Question

feeds@yuku.com (pearow) — Thu, 14 May 2009 15:57:27 GMT

Thats my favorite configeration also; a 780 plus 6 inches; and a 780 plus 3 inches; both 6 weights or approximate-p-

Re: SPG 720/780 Taper Question

feeds@yuku.com (taniwha2) — Thu, 14 May 2009 14:16:43 GMT

I'm with you in the 720 vs 780 and I get the the gist of the formula. But a 780 extended 6" seems faster and much more powerful ....

Re: SPG 720/780 Taper Question

feeds@yuku.com (Nijinski) — Thu, 14 May 2009 10:23:19 GMT

Thanks Tom!

Appreciate the engineering side of it...now I'll just have to try to wrap my head around that formula!

AK

Re: SPG 720/780 Taper Question

feeds@yuku.com (jgestar) — Wed, 13 May 2009 21:00:33 GMT

Yes, the taper increases and that 6" portion of the rod will flex "less" than any other 6" portion of the rod. But flexing less is still flexing. So the overall flex of the rod increases - you are adding the total flex of the 720 rod to the flex of the additional 6" portion. That small amount of deflection of the 6" portion, when leveraged through the remaining 72" of rod blank is a big movement at the tip.

Since you asked about the engineering,...

Re: SPG 720/780 Taper Question

feeds@yuku.com (Nijinski) — Wed, 13 May 2009 20:28:02 GMT

But with adding extra material at an increasing taper, aren't you adding material that will flex less than the thinner part of the taper, giving you a blank that does not bend as far down in proportion to the overall length of the rod? Also, what started this for me, is I can't understand how adding material at an increasing taper will decrease the power of the blank (i.e. 720 rating at 5/6 and 780 rating at 3/4).

The wooden...

Re: SPG 720/780 Taper Question

feeds@yuku.com (gypsy) — Wed, 13 May 2009 18:08:43 GMT

Think of two wooden dowels of the same diameter but one longer than the other. The longer one is more flexible than the other one.

Re: SPG 720/780 Taper Question

feeds@yuku.com (jgestar) — Wed, 13 May 2009 17:52:06 GMT

Think of it this way. If the 720 and 780 have the same basic taper, but the 780 is 6 inches longer, you have added 6 extra inches of fiberglass to the 780. Fiberglass bends. The first 72 inches of the 780 rod blank will bend at least as much as the 720 PLUS you will have the additional bend that can occur in the extra 6 inches. That results in a more flexible rod.

Tom

Re: SPG 720/780 Taper Question

feeds@yuku.com (pearow) — Wed, 13 May 2009 14:49:55 GMT

well, I was with you on that until i was corrected by more knowlegeable folks on this board. Shortening the rod actually makes the rod faster. Like i said I thought like you, but it does. I was wrong. I'm not an engineer but you can take a 720 and test it on the Cents scale; cut off 6 inches and test it again and it'l take more pennies to bend it 1/3 its length. Makes me scratch my noggin, but it does. I have found that on the 720 and 780 blanks the only consistency is inconsistency....

SPG 720/780 Taper Question

feeds@yuku.com (Nijinski) — Wed, 13 May 2009 12:59:29 GMT

I've built up a couple of the spg 720's and 780's lately, and I've now got myself quite confused. In examining the two blanks, it appears that they have the same taper, but the 780 is just 6" longer than the 720.

It seems the general conscensous is the 720 makes a good 5/6, and the 780 makes more of a 3/4. My question is, if these two blanks do have the same taper, how is it that the 720 is supposedly a more powerful rod?

I'm fairly green in...