Parabolic action ?

Discussion of sea fishing rods, boat, beach, surf casting and spinning rods.
Post Reply
PaulS
Member
Member
Posts: 8
Joined: Fri Nov 20, 2009 12:00 am

Parabolic action ?

Post by PaulS »

If a rod review describes a rod's action as mainly parabolic, what does this mean, what other types of action are there and what does it affect ?



manic_muppet
Honorary Member R.I.P
Posts: 3722
Joined: Mon Apr 07, 2008 12:00 am
Location: Bradford, W/Yorks

Post by manic_muppet »

Good question paul, and the answer would appear to be one of many, check this out.
http://www.physicsclassroom.com/mmedia/vectors/bds.cfm

Dont ask me what it all means, but theres lots more to this. :-/

eccles
Advanced User
Advanced User
Posts: 3537
Joined: Thu May 19, 2005 12:00 am
Location: East Devon

Post by eccles »

Rather silly description to apply to a rod, the word is usually used to describe the characteristics of objects such as astronomical telescope mirrors and lenses, also certain other shaped mirrors such as those used in spotlights and car headlamps. A parabola is a curved line of which the gradient of the curve continually changes according to a calculus formula. I guess the guy who wrote it might be referring to it's having a fairly floppy tip but not sure.

essexkenny
Regular
Regular
Posts: 357
Joined: Sun Sep 23, 2007 12:00 am
Location: Canvey del Sol, Essex

Post by essexkenny »

Well looking at a few pages online, a parabola is a shape which looks a lot like two sides of a triangle with the corner between them turned into a curve if that makes much sense............
So I would say that a parabolic ationed rod, would be a rod with a stiff butt and a relatively stiff tip but a flexible middle, so it bends more in the middle rather than the tip actioned rods which bend at the tip and have a stiff butt.

mac47
Occasional
Occasional
Posts: 115
Joined: Sun Dec 28, 2008 12:00 am
Location: jedburgh

parabola

Post by mac47 »

In Economics we use a bell curve as a visual aid to display the effect of increasing or decreasing inputs. As Kenny said it is a V with a curved bottom = a parabola.
The shape of the parabola can alter dependant on the data inputs:
more carbon = wider parabola - the V widens
Less carbon = narrower parabola - the V narrows
Thus the higher carbon content reduces the bend but increases the potential (in this case) energy.
Inputting the variables of strength, build and casting skill of the enduser will alter the parabolic action of any specific rod. This obviously makes determining the mean parabolic action of the rod difficult, as no two people have the same physique or skill.
The conclusion must be that in this case eccles has got it right and it is 'silly'. An alternative hypothesis is that it is marketing bull.... :)

Mac.
Ps. This answer has been developed using similar research as the marketing person who thought of using 'parabolic action' for a fishing rod ;)

Iknowagoodplaice
Regular
Regular
Posts: 409
Joined: Sun Jul 26, 2009 12:00 am
Location: Surrey

Post by Iknowagoodplaice »

If it's any help, the path a sinker follows on a cast is a parabola. (If you really want a mathematical definition see Wikipedia or a million other sites).

As to what it means for a fishing rod, I doubt the reviewer even knows. I imagine if you hang a lead off the end it will bend into a parabolic shape, which probably applies to just about any useful fishing rod.

As others say, probably marketing waffle. But I sometimes wonder how rodmakers go about designing rods. They presumably do have some parameters behind all the guff in tackle catalogues.

joliroger

Post by joliroger »

I thought it was to do with drinking to much!!!!!!!!!!! =D>

kirk
Member
Member
Posts: 46
Joined: Thu Oct 11, 2007 12:00 am
Location: Herts

Post by kirk »

Don't think that a rod could ever be parabolic, they are tapered and this would prevent it taking a parabolic curve. It might make it hyperbolic however, possibly elliptical, and it would depend on if it is at rest with a weight or under a load when casting.
The "classic" parabola is x=y^2.

joliroger

Post by joliroger »

THERE TOLD YOU, I WAS SURE IT WAS TO DO WITH DRINKING TOO MUCH!!!!!!!!!!!!!!!!!!! >:)

mac47
Occasional
Occasional
Posts: 115
Joined: Sun Dec 28, 2008 12:00 am
Location: jedburgh

Post by mac47 »

joliroger wrote:THERE TOLD YOU, I WAS SURE IT WAS TO DO WITH DRINKING TOO MUCH!!!!!!!!!!!!!!!!!!! >:)
Before I end up drinking too much >:) can someone please tell me what a ' T ' curve is? I've got a rod that claims T curve technology but it has me baffled. Cos no matter what angle I look at it I can't see the curve in the T .

Mac

PaulS
Member
Member
Posts: 8
Joined: Fri Nov 20, 2009 12:00 am

Post by PaulS »

OK, Thanks for your efforts. For the record I know what a parabola is, I just couldn't see how it applied to the action of a fishing rod.

For the record I was looking at lure rods on the Decathlon website where there rod descriptions refer to parabolic action to assist casting and point action to assist accuracy. No doubt I'm about to be slated for using Decathlon instead of a proper tackle shop but soorry, I live in Spain where my limited experience of tackle shops is pretty disappointing.

Paul

mac47
Occasional
Occasional
Posts: 115
Joined: Sun Dec 28, 2008 12:00 am
Location: jedburgh

Post by mac47 »

Hi Paul,
You will not get slated on here cos its obvious none of us has a clue how a parabola or T curve for that matter is related to a fishing rod. Hence the digs at the rod manufacturers for coming up with very tenuous claims and psuedo - scientific descriptions for rods.
The older hands amongst us and I suppose some of the younger tackle tarts have all been caught out at one time or another with descriptions of tackle.
My failing was to buy rods that were way to powerful for me to bend and ultimately cast i.e Tcurve.
What decathlon rods are like I don't know but if you want to play it safe I would stick to better known names like Daiwa, Shimano etc. I have a couple of friends who use Garbolino sea rods and reckon they are brilliant. They are an Italian firm and maybe they will have an outlet somewhere near you in Spain.
Mac

robc22
Advanced User
Advanced User
Posts: 623
Joined: Wed Oct 15, 2008 12:00 am
Location: the beach

Post by robc22 »

slow taper rod that bends down to the handle.....usualy made of glass not carbon fibre.Great delicate bait slinging rods

PaulS
Member
Member
Posts: 8
Joined: Fri Nov 20, 2009 12:00 am

Post by PaulS »

Thanks again.

Being relatively new to shore fishing can anybody recommend any good books that go into the tschnicalities of different rod qulities, and reels for that matter ?

I've read a couple that cover basic knots, terminal rigs etc but nothing technical about rods and reels or how to determine what's suitable for what.

Post Reply