I received this five-piece beauty and made a romantic pairing with my grandfather's Dam Quick from 1973, then did a little swapping for a Martin MG-8.
This 7 1/2' rod has a narrow butt and flexes easily into the grip, and is rated for 1/8 - 3/8 oz lures or six weight fly line. I hate to say it, but it feels darned good as a six weight fly rod! I wonder if it shares a common blank with something like the FF756? I look forward to fishing it as a fly rod, but it will see most use tossing spinners for bass.
It's a testament to the Aetna Foul-Proof guides that they came through unscathed after the seller jammed the rod into the tube with force. I thought for sure a couple would be seriously damaged.

Nice looking rod and setup there. Out of curiosity, what letter does the serial number start with.

That's a sweet looking Fenwick.

Old post, I know. I have a Fenwick 5-piece just like this as well as a Fenwick 4-piece eight foot pack rod also spin/fly for 1/8 to 3/8 lures.

IMHO these are both noodle rods with spin gear. Just for fun, I put them on the wall added different weights to the end and measured the flexural characteristics.

Short answer is that these rods bend a lot more like fly rods than spinning rods. You could use it either way but there are better casting rods if your primary intent is spinning gear.

If my primary intent was going to be with a fly line, I would grab one of the Fenwick's in a heartbeat.

So many variables, and so many personal references. A fishing rods performance in any situation (relative to a different rod) is dependent upon the rods materials of construction, geometry guides spacing and size; weight of lure and bait; line tensile strength, flexibility and diameter; reel and spool dimensions, and specific fishing conditions. I don't think there is anything controversial or new with this statement. Every rod maker has and continues to make a variety of model rods trying to hit that sweet spot for all of us.

Unfortunately, rod design is kept as much a mystery as possible and the consumer is left with trying as many as possible until he or she finds the "perfect" rod. We defend this decision with our honor.

I have have tried to decipher some of the mystery by reverse engineering some of the specifics of the rod itself that leads to the performance I prefer. My previous post was just one simple observation on the Fenwick rod in the OP. No offense taken by the subsequent poster whose opinion is just as valid.

It is possible to calculate the actual deflection of any item (such as a fishing rod) if you know a few constants in the equation such as: geometry of the item, modulus of elasticity of the material of construction, and the mass applied during the test, and the placement of the mass during the test.

Example: The equation to determine the deflection at the end of a cantilevered fishing rod with a weight placed at the end would be: PL cubed divided by 3EI
P being the load applied
L being the length of the rod
E being the modulus of elasticity
and I being the section modulus of the material
I won't bother you with the details of the units and any actual calculations because they are not important to this discussion or the reverse engineering I am messing with.

What is important is that if you are examining rods of the same length, then L is the same of those rods, Likewise if you use the same weight and place it at the end of the rod, then P or the mass of the load is also a constant. The number 3 is also a constant.

This leaves the only variables left in the equation to be the physical geometry of the rod itself and the modulus of elasticity of the material. In actuality how these two factors achieve a certain deflection (or bend in the rod) is immaterial except a higher modulus material such as graphite, will need a smaller section modulus to achieve the same deflection. This means lighter rods with the same performance can be made out of graphite. Nothing new here.

Every rod make since bamboo has messed with different materials of construction and different geometry to woo us into buying their perfect rod. By adjusting both the E and the I in the equation, they can create a rod that bends where and by as much as they want. There are practical limits of course.

So back to measuring actual deflection. By doing this, you can physically see where the bend (deflection) of any rod occurs and how much that bend is. Rods with similar deflection characteristics perform very similarly when all of the other variables are the same. i.e. the same reel, same line, and same bait on any given water and with any given expected fish (P).

By examining the deflection characteristics of the rods I prefer for certain applications and comparing them to other rods, I have not used before, I can quickly select an application that the rod might be best suited for.

My earlier comment did not elaborate, but a fiberglass fly rod with a soft and forgiving presentation typically bends more uniformly throughout its length and less at the tip. Some graphite rods are much more aggressive and show less deflection in the butt section. Fiberglass spinning rods typically are stronger in the butt section with less deflection there and about the same deflection in the tip as a similar length fly rod. Thus my observation on the Fenwick. Similar end deflection, but a weaker butt section which tends to make it noodle(y) in my view but, not necessarily bad.

I could go on in this vein, but I am already running off at the mouth. Hope these observation prove useful to someone. If anyone wants more detail on my data feel free to send me a PM.

Bulk modulus as you are using it is the modulus of elasticity times the moment of inertia. Not sure what you think I said that is not true?? The equation I cited is a standard cantilever deflection equation for a load placed on the end.

I skipped over rod taper (but am not ignorant of it) simply because a deflection curve also takes into account the taper and any other rod specific variables such as changing materials of construction through-out its length. i.e. the changing bulk modulus or taper.

Perhaps you are missing the point that I wanted to make which is: in response to the OP and the Fenwick (nice by the way) originally shown, that it performs more like most conventional glass fly rods than most conventional glass spinning rods.

My follow up post was intended to demonstrate that without going into all of the details of design, you can physically measure a rods performance simply based on deflection characteristics. This is useful for older rods of unknown design for which there is no other practical way to obtain the flexural characteristics without cutting it into an infinite number of pieces. Simply a practical way to compare how one old rod will perform in relation to another.

Not trying to initiate a fishing rod design course here.