Do you fill up your spool?

[Ratherbfishing]

An optimist says the spool is half full while a pessimist says it is half empty.

[Team9nine]

7 minutes ago, Ratherbfishing said:

An optimist says the spool is half full while a pessimist says it is half empty.

And a measurebator says, "How will that difference affect my fishing?"

-T9

[.ghoti.]

John, your lever example applies. When pulling line against the drag, the further the line is from the spool center, the easier it is the "move the rock". 

In addition, centrifugal braking force changes as line is removed. Your bait is moving the fastest at the beginning of the cast. If the spool is only half full, it has to rotate faster to keep up, producing more braking force from a centrifugal system, and from a centrifugally activated magnetic system.

This would be why some recommend using a half filled spool for pitching.

[J Francho]

2 hours ago, cutbait said:

" Reel drag systems are governed by the torque equation (torque  = force x radius).  In the case of reels, the radius is actually the distance from the center of the spool to where the line exits.  This explains why the more line there is on the spool, the less drag you exert.  All else being equal, if the diameter on the spool is reduced to half, then the line tension would double."

That's well put - I can get my tiny brain around this.  Thanks posting it up.

[fissure_man]

For the dorks, here's the math behind it:

F = normal force applied to drag stack (star drag setting)

P = pressure on drag washer (assumed to be uniform)

R_i = inside radius of drag washer

R_o = outside radius of drag washer

μ = drag coefficient of friction

The strength of the drag amounts to the resistive torque it can develop due to friction on the drag washer surface.  To calculate this, consider the washer broken down into infinitesimally small ‘rings,’ of thickness ‘dr’, radius ‘r’.

The surface area of each of these rings ‘dA’ (infinitesimal approximation) is given by:

dA = (2πr)*(dr)

Total area of the washer is given by

A = (π)*(R_o² – R_i²)

The portion of the drag stack force (F) that acts on the infinitesimal ring can be called dF.  Recall that the uniform pressure on the drag washer is ‘P’.  Force = Pressure x Area:

dF = (P)*(dA)

substitute from above:

dF = (P)*(2πr)*(dr)

Likewise, for the whole washer:

F = (P)*(A) = P*(π)*(R_o² – R_i²)

P = (F)/(π)*(R_o² – R_i²)

Frictional force is calculated as coefficient of friction (μ) x normal force.  At the slip point of the drag, the frictional force from each infinitesimal ring is therefore (μ)*(dF).  The resistive torque produced by this force (call it dT) depends on the radius of the ring (r):

dT = (μ)*(r)*(dF)

subsitituting for dF:

 dT = (μ)*(r)*(P)*(2πr)*(dr) = (μ2πP)*(r²)*(dr)

The total resistive torque supplied by the drag (T_drag) is calculated by integrating the incremental torque over the area of the drag washer, from r = R_i to r=R_o:

T_drag = (μ2πP)*(1/3)*(R_o³ – R_i³)   

subsitituting for P:

T_drag = [(F)*(μ2π)*(R_o³ – R_i³)]/[(3)*(π)*(R_o² – R_i²)]

simplify:

T_drag = (2/3)*(μ*F)*[R_o³ – R_i³]/[R_o² – R_i²]

SO: the max frictional torque supplied by the drag (T_drag, about the crank shaft) depends on the coefficient of friction (μ), the normal force (F - drag star setting), and R_o/R_i which define the surface area of the drag.  This makes sense, and is unaffected by spool diameter.

 

Now we work from the other end (the line).  This is much simpler:

A = tension (force) on the fishing line

R_eff = effective spool radius (distance from the spool shaft axis to the ‘pull point’ of the line)

G = gear ratio (main gear vs pinion gear)

Pulling on the line applies a torque to the reel’s drag system, working in the opposite direction to the frictional torque of the drag.  When this torque equals the max frictional torque, drag slip occurs.

Torque around the spool axis (T_s) is calculated as:

T_s = (A)*(R_eff)

Multiply ‘T_s’ by the reel’s gear ratio (G) to determine the resulting torque around the crankshaft (T_c) (recall that ‘T_drag’ is relative to the crankshaft as well).

T_c = (A)*(R_eff)*(G)

At the onset of drag slippage, T_c = T_drag.   Substitute, then rearrange:

A = (T_drag)/[(R_eff)*(G)]

This equation shows that for a larger effective spool radius (R_eff), such as a full spool vs. a half-empty spool, the tensile force required to induce slippage (A) is lower with the same drag setting.  Interesting side note:  the same logic applies to the gear ratio – higher gear ratio reels will achieve lower drag resistance, all other variables being equal (this also applies to the “max” drag under full lockdown). 

We can also confirm that A and R_eff, are inversely, linearly proportional.  Doubling R_eff results in halving the tensile force to induce slippage (A).  J Francho – do your results confirm this?

 

This still doesn’t get into drag consistency in actual use, as any sane bass angler will offset the difference in ‘A’ (tension to induce slippage) by adjusting the drag star (increase/decrease F), which increases/decreases ‘T_drag’. 

Consider a reasonable example to test the idea of a full spool offering more consistent drag performance:

Filled spool effective diameter: 1.4 (R_eff = 0.7)

Under-filled spool effective diameter: 1.2 (R_eff = 0.6)

Spool width = 1.5

Let’s consider that a cast with the filled spool results in a drop of 0.1 in R_eff, due to line leaving the reel.  This corresponds to a certain ‘volume’ of line, as it sits packed on the reel.  Assuming line on both reels is ‘packed’ to similar density, we can determine a corresponding decrease in effective radius for the same length cast with the less-filled reel.

Volume of a cylindrical shell (similar to the area of the washer discussed above):

V = (π)*(a²-b²)*(h)

where:

a = initial R_eff (pre-cast)

b = final R_eff (post-cast)

h = spool width

With the assumption above for the fully spooled reel, we calculate the volume of line involved in the cast:

a = R_eff = 0.7

b = R_eff – 0.1 = 0.6

h = 1.5

V = (π)*(0.7²-0.6²)*(1.5) = 0.613

With the less-filled spool, this volume should be unchanged (assumption).  We can then solve for b in the less-filled scenario:

0.613 = (π)*(0.6²-b²)*(1.5)

b² = (0.6²)-[(0.613)/(1.5π)]

b = 0.48 (this is the final R_eff for the less-filled case, post cast)

 

Recall the equation to determine tensile force to induce drag slippage (A):

A = (T_drag)/[(R_eff)*(G)]

For the same cast, with a full spool:

R_eff = 0.7 (pre-cast), 0.6 (post-cast).  A_post-cast = (0.7/0.6)*(A_pre-cast) = 1.17 times greater drag resistance

For the same cast, with a less-filled spool:

R_eff = 0.6 (pre-cast), 0.48 (post-cast).  A_post-cast = (0.6/0.48)*(A_pre-cast) = 1.25 times greater drag resistance

 

So, for a full spool, with the measurements as described, the range of drag resistance achievable during your cast ranges from 1-1.17 times the amount you set it at when you have no line out.  With a less-filled spool, the achievable drag resistance ranges from 1-1.25 times the amount you set with no line out. 

In summary, the difference in drag performance for varying effective spool sizes for any size reel is significant if the drag mechanism (drag star) is not adjusted to compensate.  The saltwater posts above give good examples of this, where effective spool size changes substantially over the course of bringing in a strong fish, necessitating adjustment ‘on the fly’.  However, as it applies to bass fishing and prior discussion, the difference in ‘drag consistency’ between a full and partially filled spool doesn’t appear very dramatic.

 

[J Francho]

saw it on wikipedia.  Had no desire to go through it all, lol.

[rippin-lips]

[J Francho]

Knuckle Draggers!

[Team9nine]

Fissure_man for President!!    

That response will teach people not to ask simple preference questions here on the forums ever again  

 

-T9 (anxiously awaiting the results of the science experiment tonight from the 9 y.o.)

[WRB]

Then you add wet multiple disks with double sides and heat, the formulas change. The difference between drag styles and disk materials can vary widely with the same reel manufacturer due to cost and design features. No 2 drags operate with same friction coeffient because you must add heating to the equation.

Bottom line; fresh water bass bait casting reels only need to operate efficiently to prevent line breaking when the bass is near the boat because that is when the forces can raise dramatically.

Largemouth, Spotted and Smallmouth bass can only swim about 15-20 mph for a few seconds, they don't make long fast runs, they make hard quick turns and jump out of the water on occasion.

Spinning reels is where a good smooth drag becomes important because of lower strength line is usually used and subject to failure more often.

Tom

 

[Jaderose]

[Further North]

9 hours ago, fishballer06 said:

Does 5.46 inches of crank make a difference?

Well, 30 IPT is around what a standard 7:1 reel recovers per turn. 24.54 IPT is around what a standard 5:1 reel recovers.

Going one step further, a 120 foot cast with 30 IPT would take 48 cranks to retrieve. That same 120 foot cast with 24.54 IPT would take around 59 cranks to retrieve. 

OK, I get that...but we're talking about the difference between a full spool and a 1/2 full spool on the same reel, with the same retrieve ratio.

I'm probably missing something obvious, but it's been a long day.

[fissure_man]

2 hours ago, WRB said:

Then you add wet multiple disks with double sides and heat, the formulas change. The difference between drag styles and disk materials can vary widely with the same reel manufacturer due to cost and design features. No 2 drags operate with same friction coeffient because you must add heating to the equation.

Bottom line; fresh water bass bait casting reels only need to operate efficiently to prevent line breaking when the bass is near the boat because that is when the forces can raise dramatically.

Largemouth, Spotted and Smallmouth bass can only swim about 15-20 mph for a few seconds, they don't make long fast runs, they make hard quick turns and jump out of the water on occasion.

Spinning reels is where a good smooth drag becomes important because of lower strength line is usually used and subject to failure more often.

Tom

 

Pfft .  No fun :-P

I'm not familiar with all types of reel drags, but I think the fundamentals are largely the same, definitely in terms of how spool diameter affects drag performance.  Anyway, it's not a comparison of different reels, it's the same reel with more or less line spooled up.

Managing and dissipating heat is important drag design, but consider the temperature constant in the analysis above.  It's not really a factor in calculating relative amounts of line tension to achieve initial drag slip, and if needed, would be accounted for in the coefficient of friction.  (Again, we're talking about the same reel with different amounts of line - it cancels out). 

Good point about the spinning reel.  The same logic would apply to those if your casts are long enough (or your spool is small enough) that the effective spool diameter is significantly changed during the course of fishing.

A situation that comes to mind where baitcaster drag performance is important on a long cast (not beside the boat) is jerkbait fishing - I have a jerkbait casting setup that I use for smallmouth fishing, spooled with braid, typically with a light mono or copoly leader, light wire hooks.  A big smallie hooked at the beginning of a cast will pull drag, and there's not much give in the braid. 

[WRB]

The drag comparison is largely hypothical regarding fresh water bass because they don't make long hard runs without turning every 10 to 20 feet, rarely run directly away from the angler more then 20 feet. If you hook into a fresh water fish that heads over the horizon it's not a LMB, Smallmouth or spotted bass, it could be a very big stripe bass, musky but even those fish stop and turn within 100 feet. Big off shore fish can and do run directly away from the angler several hundred yards at high speed and the reel drags over heat and can stop working becoming glazed....bye bye fish and all your line.

Tom

[fissure_man]

I kind of agree, but there's a reason you don't just lock down your drag on all bass reels.  If you're using light line or light hooks, having a smooth and consistent drag is important, even if the bass is going to give up its run long before it burns out your reel.

None of this is about drag performance during long, blistering runs from offshore fish (where heat dissipation is a major factor).  My posts are about line tension to achieve initial drag slip, which is very relevant to bass fishing.

[WRB]

24 minutes ago, fissure_man said:

I kind of agree, but there's a reason you don't just lock down your drag on all bass reels.  If you're using light line or light hooks, having a smooth and consistent drag is important, even if the bass is going to give up its run long before it burns out your reel.

None of this is about drag performance during long, blistering runs from offshore fish (where heat dissipation is a major factor).  My posts are about line tension to achieve initial drag slip, which is very relevant to bass fishing.

Bass fishing is simple; you set the drag at 1/3 rd the line strength for mono dia's and forget it.

I have caught more DD bass then any other member on this site and used 10 to 12 lb line with the drag set at 3 to 4 lbs using a scale without any drag related issues over 40 year period. End of discussion!

Tom

[fissure_man]

16 minutes ago, WRB said:

I have caught more DD bass then any other member on this site and used 10 to 12 lb line with the drag set at 3 to 4 lbs using a scale without any drag related issues over 40 year period. End of discussion!

Tom

The thread is about the pros and cons of filling or underfilling your spools.  This led to discussion of the potential differences in drag performance for filled vs. underfilled spools, which I think is an interesting question.  Nit-picking? Sure. Negligible? Probably.  But still fair game to talk about.

The number of DD bass you've caught and your chosen drag settings not only don't end the discussion, they are irrelevant.

OP: sorry for the hijack 

[WRB]

1 hour ago, fissure_man said:

The thread is about the pros and cons of filling or underfilling your spools.  This led to discussion of the potential differences in drag performance for filled vs. underfilled spools, which I think is an interesting question.  Nit-picking? Sure. Negligible? Probably.  But still fair game to talk about.

The number of DD bass you've caught and your chosen drag settings not only don't end the discussion, they are irrelevant.

OP: sorry for the hijack 

Irrelevant! You are barking up the wrong tree.

The spool diameter does affect the torque applied to a drag washer.

Lets use extremes; 3" diameter spool with 1" diameter drag washer.

The line pulling on the OD of  a full spool of line  at 3"  verses the same reel at 1" diameter of line on the same spool that equals the drag washer diameter. What do you think the torque differential will be equal to the full 3" diameter spool or less than the 3" diameter spool with only 1" diameter of line? The answer should be obvious.

The surface area of the 1" OD diameter drag washer doesn't change, the lever arm of line pulling the spool around changes as the spooled line diameter changes, the only force available, directly affects the torque applied to the spool shaft.

Tom 

PS, let know if you have ever caught a bass, this is a fishing forum.

[fissure_man]

48 minutes ago, WRB said:

Irrelevant! You are barking up the wrong tree.

The spool diameter does affect the torque applied to a drag washer.

Lets use extremes; 3" diameter spool with 1" diameter drag washer.

The line pulling on the OD of  a full spool of line  at 3"  verses the same reel at 1" diameter of line on the same spool that equal the drag washer diameter. What do you think the torque differential will be equal to the full 3" diameter spool or less than the 3" diameter spool with only 1" diameter of line? The answer should be obvious!

I'm aware of this, in fact it's been beaten to death in the above posts (mine included).  What matters is the tension on the line to induce drag slippage.  The same tension can be achieved for different spool diameters by adjusting the drag setting.  Considering that anglers adjust their drags to their preferred line tension, regardless of spool diameter (or 'fullness'), the question becomes: is there any difference in performance and consistency of a properly set drag at different levels of spool 'fullness'.  For more on this, re-read the thread.

Edit for clarity:  I'm of course not saying that the discussion of spool diameter and how it affects drag performance is irrelevant to the thread (should be obvious from my posts), I was referring to your DD record and your 3-4 lb drag tension setting, which you presumably employ with spools of all diameters.

48 minutes ago, WRB said:

PS, let know if you have ever caught a bass!

Good one. 

[WRB]

16 minutes ago, fissure_man said:

I'm aware of this, in fact it's been beaten to death in the above posts (mine included).  What matters is the tension on the line to induce drag slippage.  The same tension can be achieved for different spool diameters by adjusting the drag setting.  Considering that anglers adjust their drags to their preferred line tension, regardless of spool diameter (or 'fullness'), the question becomes: is there any difference in performance and consistency of a properly set drag at different levels of spool 'fullness'.  For more on this, re-read the thread.

Good one. 

The real problem with pre set drag force is leaving the force set for days without loosening the pressure. The drag bevel or cupped washers take a set creating very high initial breakaway forces that result in line or knot failure. This is a real issue not a hypothical, not related to spool line diameter.

Tom

[fissure_man]

8 hours ago, WRB said:

The real problem with pre set drag force is leaving the force set for days without loosening the pressure. The drag bevel washers take a set creating very high initial breakaway forces that result in line or knot failure. This is a real issue not a hypothical.

Tom

Real, but unrelated to spool diameter.

My "hypothetical" claims are about to be proven by Francho's 9-year-old, just you wait. 

Edit: Please leave a note when you edit your posts, especially after they've been replied to.

[WRB]

9 hours ago, fissure_man said:

Real, but unrelated to spool diameter.

My "hypothetical" claims are about to be proven by Francho's 9-year-old, just you wait. 

Edit: Please leave a note when you edit your posts, especially after they've been replied to.

Don't need to wait, know the answer.

I often edite my post after getting a chance to read them, you just wait.

Tom

[fissure_man]

1 hour ago, WRB said:

Don't need to wait, know the answer.

Great, can you clarify then what you're even disagreeing with?   I'll do the same:

19 hours ago, WRB said:

Then you add wet multiple disks with double sides and heat, the formulas change.

Yes, but the relevant fundamentals are the same.  Frictional heat generation is not a factor in determining the tension to induce initial drag slip.  Your own posts imply that that rising drag temperature is not a huge factor in most bass fishing situations, because they don't make long runs, and I agree.

19 hours ago, WRB said:

No 2 drags operate with same friction coeffient because you must add heating to the equation

Fair enough, but we're comparing the same reel with different amounts of line.  See above comments on heat.

19 hours ago, WRB said:

Bottom line; fresh water bass bait casting reels only need to operate efficiently to prevent line breaking when the bass is near the boat because that is when the forces can raise dramatically.

This is the most critical time that your drag will be tested, but my experience with smallmouths/low stretch braid/light leaders/light hooks shows that a decent fish can pull through the drag away from the boat as well.  Hence the validity of at least discussing how spool fullness might or might not impact drag performance (ie: at the start or end of a cast, EDIT: and for spools filled to varying levels at or below their max capacity).

19 hours ago, WRB said:

Spinning reels is where a good smooth drag becomes important because of lower strength line is usually used and subject to failure more often.

Agreed.  But most of this discussion could apply to spinning reels as well.  And I'd argue that light line baitcasting is not unheard of, and is a rising trend in NA.

16 hours ago, WRB said:

The drag comparison is largely hypothical regarding fresh water bass because they don't make long hard runs without turning every 10 to 20 feet, rarely run directly away from the angler more then 20 feet.

It's not "hypothetical" or irrelevant to bass fishing, unless you've never had a bass pull through your drag.  Drag performance, especially the consistency in tension to induce slippage is very relevant to bass fishing.  An improperly set or poorly performing drag can cause you to lose bass, even if they're not towing you around the lake.  On the other hand, your comments about heat generation and dissipation are not especially relevant, for the reasons you are stating.

11 hours ago, WRB said:

The line pulling on the OD of  a full spool of line  at 3"  verses the same reel at 1" diameter of line on the same spool that equals the drag washer diameter. What do you think the torque differential will be equal to the full 3" diameter spool or less than the 3" diameter spool with only 1" diameter of line? The answer should be obvious.

This is essentially the same scenario I gave a detailed explanation of and expanded on in prior posts.  The answer is obvious; how it could affect drag performance in actual use, is not.  Which brings me back to the original question: which of these claims are you saying is false? 

(PS: nit-picking, but the torque around the spool shaft generated by line tension is independent of the drag washer diameter)

[J Francho]

I think we're done here...