Exploring Fishing Rod Weight and Casting Distance: A Newbie's Question

[rdchin71]

TL;DR Summary

My question is - if there are 2 fishing rod, one lighter than the other. Will the lighter fishing rod cast a lure/bait further than the heavier fishing rod, assuming the rod length, lure/bait weight and everything else is constant.

Hello, I am new to this forum.

I have a question, hope I'll find some answers here.

My question is - if there are 2 fishing rod, one lighter (physical weight) than the other. Will the lighter fishing rod cast a lure/bait further than the heavier fishing rod, assuming the rod length, lure/bait weight and everything else is constant.

Thank you for taking the time to reply!

 

[ZapperZ]

It isn't just the weight, but rather the stiffness and flexibility of the rod. If you are doing fly-fishing, for example, how much the rod bends allows you to store potential energy in it and so when it "unbends", all that energy can be transferred to cast your lure far away.

Light weight-material can have high stiffness (carbon fiber) the same way heavier ones do. So it isn't just about the weight, but also the material.

Zz.

 

[rdchin71]

Thank you for the reply.

As I have mentioned, everything else is constant which includes the flexibility of the rod.

 

[ZapperZ]

Thank you for the reply.

As I have mentioned, everything else is constant which includes the flexibility of the rod.

Then you have just asked an impossible question. Two objects of identical material and identical dimensions and shape can't have different weights.

Zz.

 

[sophiecentaur]

The performance and skill of the angler are by far the most important factors. Baseball and cricket bats are widely discussed in fora and iirc, it’s a matter of matching bat weight to the user’s characteristics.
Science and calculations are often Ill suited to these things, especially when an experienced user is involved.
The adverts will not be reliable sources of opinion.

 

[anorlunda]

Science and calculations are often Ill suited to these things, especially when an experienced user is involved.

Well said. That's the point @rdchin71 , it is not a science question.

 

[ZapperZ]

Well said. That's the point @rdchin71 , it is not a science question.

No, I disagree that this was his/her point. He/she posted this in a science forum, and specifically in the Classical Physics forum. What non-science motive can there be?

And I do agree that in the end, this is more of a skill issue rather than an equipment issue. But I still stand by my claim that given the parameters that the OP has stated, this is an impossible question.

Zz.

 

[berkeman]

As I have mentioned, everything else is constant which includes the flexibility of the rod.

Assuming that two rods of equal characteristics except for weight can be made, the heavier one will have a slower angular acceleration (given the same torque applied by the angler). That slower acceleration will result in a lower linear velocity for the lure end of the line, so it will travel a shorter distance.

If the angler can vary their strength (torque applied during casting), and can launch the two lures with the same linear velocity, then they will travel the same distance.

 

[Lnewqban]

I agree with berkeman.
Everything else being equal, including the weight distribution along the rods, as well as the input torque and angular displacement of both rods:
The lower moment of inertia or rotational inertia of the lighter rod would result in a greater angular acceleration.
That will produce a higher initial velocity of the bait, which should fly farther.
This is equivalent to how the mass of a body determines the force needed for a desired linear acceleration.

 

[sophiecentaur]

Well said. That's the point @rdchin71 , it is not a science question.

I agree and, of course, you will never get an 'answer' to the question but it is interesting to consider the question and posts like:

Assuming that two rods of equal characteristics except for weight can be made, the heavier one will have a slower angular acceleration (given the same torque applied by the angler). That slower acceleration will result in a lower linear velocity for the lure end of the line, so it will travel a shorter distance.

If the angler can vary their strength (torque applied during casting), and can launch the two lures with the same linear velocity, then they will travel the same distance.

and

I agree with berkeman.
Everything else being equal, including the weight distribution along the rods, as well as the input torque and angular displacement of both rods:
The lower moment of inertia or rotational inertia of the lighter rod would result in a greater angular acceleration.
That will produce a higher initial velocity of the bait, which should fly farther.
This is equivalent to how the mass of a body determines the force needed for a desired linear acceleration.

prove it. But neither post includes a fully characterised angler body with a known 'performance'. It would spoil the fun of the whole exercise to substitute the angler with an electric motor with a given power output and an optimised gear box to rotate the rod and ' let go' at precisely the right instant. I know all about incompetence and randomness in using a rod and reel, so I speak with great authority here.

 

[rdchin71]

Assuming that two rods of equal characteristics except for weight can be made, the heavier one will have a slower angular acceleration (given the same torque applied by the angler). That slower acceleration will result in a lower linear velocity for the lure end of the line, so it will travel a shorter distance.

If the angler can vary their strength (torque applied during casting), and can launch the two lures with the same linear velocity, then they will travel the same distance.

This is exactly what I thought.

Assuming I made a rod (rod A) that is X% lighter than rod B. They both have the same flex, same strength, same length, characteristic etc and I have the same person casting with each rod, common sense tells me that “rod A” should cast further as per Berkeman stated.

If I want to market “Rod A” as an invention that has superior casting capabilities compared to what is available in the existing market because it is physically lighter in weight and thus able to cast longer distances. How do I convince quoting a law of physics or the science behind it.

Thank you once again for the participation. I am not physics trained so I hope what I mentioned made sense.

 

[berkeman]

Hopefully you have seen from the replies in this thread that if you want to create a rod that casts very far, you don't just vary the weight. There is much more that goes into creating a great casting rod (including developing the skills to use it well).

How long have you been fishing, and what kind of fishing have you done so far? What is your favorite rod/reel for casting for Bass so far, and what do you like about it? Have you learned to fly fish yet? If so, what rod and line combination do you like the best?

https://www.bradwiegmann.com/images/stories/Bass_Pros/Cameron_Gautney/Cameron-casting.jpg

https://troutbitten.com/wp-content/uploads/2018/02/Troutbitten_Josh_Darling_Angler-Green-Casting.jpg

 

[256bits]

If I want to market “Rod A” as an invention that has superior casting capabilities compared to what is available in the existing market because it is physically lighter in weight and thus able to cast longer distances. How do I convince quoting a law of physics or the science behind it.

Didn't you just say

Assuming I made a rod (rod A) that is X% lighter than rod B. They both have the same flex, same strength, same length, characteristic etc and I have the same person casting with each rod

You are going overboard here, as to what is superior.
Lighter doesn't mean that the lure can be cast a farther distance unless you are comparing a "lighter" rod to someone using a telephone pole weight rod.<-- hyperbole if you didn't notice. The user would, change his style and torque on the rod to compensate. In addition, there probably is "feel" that each particular user would just like for a rod being made just for him. Some might like a bit of weight, and some might not. Too light of a rod, and you might get complaints that there is nothing there. As said before, it is not just about lighter being better for a cast, but many casts.

What comes into play with lighter is continued use, and less fatigue for the user over repetitive castings.

And some weight balance between lure weight and the rod and handle weight I suspect.

 

[sophiecentaur]

Assuming I made a rod (rod A) that is X% lighter than rod B. They both have the same flex, same strength, same length, characteristic etc and I have the same person casting with each rod, common sense tells me that “rod A” should cast further as per Berkeman stated.

If I want to market “Rod A” as an invention that has superior casting capabilities compared to what is available in the existing market because it is physically lighter in weight and thus able to cast longer distances. How do I convince quoting a law of physics or the science behind it.

Thank you once again for the participation. I am not physics trained so I hope what I mentioned made sense.

Here's a though that may add fuel to this fire and shows, even more, how there are too many variables for a Physics approach. One of the essential factors in a useful casting rod is the fact that it actually stores energy like a spring. It carries on delivering energy to the tackle, long after you can't put any more in from your muscles (your arm is now pointing out forwards but the rod tip may be just abeam of you). The weight (mass) of the moving rod contributes to the available energy at this stage. As with bats, there is a limit to muscle power available but, otoh, a massless rod would carry no Kinetic Energy; there will be an optimum, depending entirely on the angler's strength, arm length etc..
The position of your two hands on the rod will affect the torque you can exert and you will choose what feels best.

Casting length depends a lot on the mass of the sinker and anglers have a range of weights to give the best cast length for the wind conditions. Different weights would call for different rods.

The good news is that, as every angler knows, it is essential to own as many rods as you can actually carry to the fishing site and almost as many reels, lures, weights, snake oil bottles etc. All this goes to make the total fishing experience what it is and allows you to experiment during each session. You do the sums, unconsciously, in your head.