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Out of interest, who came up with the ratio of ten pounds line strength for every ounce that's cast. Is there an actual scientific equation to back up this advice? Depending on your style of cast you can cast surprisingly good distances without a leader. I'm not saying we should all go out and ditch our leaders, because that would be stupid, but it would be nice to see some evidence to back up the advice.
 

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Pass. Another thing people tend not to think about is bait size, a big cod bait will sometimes be as big as 4oz maybe more, so when used with 8oz lead this would in theory need a 120lb leader using the ratio of 10-1. I tend to stick to 80lb up the Bc and have never had a problem.
Do they use the same ratio in casting events when not using bait? If so then maybe it's just as importanmt when fishing, if not more.
 

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The formula has to do with the actual loading put on the lead during the cast by the lead weight, rod (flexing) and the mechanics of the cast.

I'm not an expert in dynamics but I would not question something that is deemed by most anglers as 'gospel'.:notworthy

I did find this from one fishing site:-

'The strength of your shockleader is dictated by the weight of the lead you are casting and your casting style.

The oft-quoted formula for leader breaking strains is 10lb for every ounce of lead cast. In other words, a 5oz sinker needs a 50lb shockleader and a 6oz lead needs a 60lb line.

For power casting styles that involve generating compression in the rod and more speed in the lead, which is achieved by swinging the lead in a wide arc (pendulum), then a further 10lb is usually added to the overall leader breaking strain as a safety cushion.

There is an allowance for common sense here. There is no comparison between a full-blooded power pendulum arc on the tournament field and a simple back swing from the pier or beach.

On the field the lead in not encumbered by rig, bait or wind direction and can therefore generate awesome power and more danger. On the beach a baited rig, the awkward stance, surrounding obstructions, a strong wind and unsure footing all reduce the power input, but can heighten the dangers.

For short-range rock fishing, or where less powerful overhead casts are used, it is possible to reduce the shockleader strength safely.

Anglers using Continental-style overhead casting methods use leaders as low as 40lb.

Even when you take precautions things can go wrong. Line damage, a thumb slipping off the reel, losing the grip of the rod or simply slipping over during the cast can all result in accidents.'


I'm sure that there will be someone out there that can baffle you with the science of how the calculation is done.:nerd: But do we realy need to know the nitty-gritty when the work has already been done for us?

Just my thoughts.
 

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If the gauge of wire used on a pulley swivel dictates the safety of a rig body does the gauge of a tip ring have any bearing on a shock leader?
Very slight, if you look at a cast in motion, and pause the point of maximum pressure, the tip ring is near enough pointing at the lead, and the subsequent rings are taking the shared load,
if this is what you meant?
 

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So theoretically can you use a lower breaking strain leader with a softer tipped rod?
yes and no, you cant powercast an 8oz lead on a soft rod designed to cast 4oz, so stick to the formula and balance the tackle to the situation
 

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yes and no, you cant powercast an 8oz lead on a soft rod designed to cast 4oz, so stick to the formula and balance the tackle to the situation
I agree, although not exactly what I was asking mate.

To put it another way would a soft tipped 4/8 oz rod impart less pressure at the tip on the leader than a stiff tipped 4/8 oz rod if both blanks had the same tip ring and overall power and were both fully compressed?
 

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I agree, although not exactly what I was asking mate.

To put it another way would a soft tipped 4/8 oz rod impart less pressure at the tip on the leader than a stiff tipped 4/8 oz rod if both blanks had the same tip ring and overall power and were both fully compressed?
No, it's not the tip that powers the cast, it's the power coming through from the butt. Both tips would be pointing at the lead
 

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Out of interest, who came up with the ratio of ten pounds line strength for every ounce that's cast. Is there an actual scientific equation to back up this advice? Depending on your style of cast you can cast surprisingly good distances without a leader. I'm not saying we should all go out and ditch our leaders, because that would be stupid, but it would be nice to see some evidence to back up the advice.
First time I saw it published I think was in "Angling" in the 70s but damned if I can remember who wrote it ... I know that I've certainly seen John Holden quote the figure just a few times ... plus 10lb as a safety margin for damage to the leader.
 

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So theoretically can you use a lower breaking strain leader with a softer tipped rod?
In theory ... but whatever rod you use to get a 150g lead x amount of yards the leader must be under pretty much the same amount of strain. The difference with the softer rod is that it just applies that strain to the leader smoothly and acts as a better shock absorber. The slower and steadier you load nylon the better for the breaking strain ... if you load it quickly it doesn't stretch evenly along its length and so its more likely to snap.

Badly explained but think of breaking out of a snag ... much easier to do when snagged 30 yards out than 100, thats because the stretch absorbs the pulling .... its the same with leaders ... floppy rods load it slower and allow it to stretch between lead and spool.

In practice only a nutter takes that kind of risk ... why bother just to reduce the leader diameter?
 

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plus 10lb as a safety margin

that's the trouble when designing anything.... people keep putting on extra safety margins.

the 'calculation' is very unlikely to have come up with a value of exactly 10, it has been rounded up to give 10 which is easy to multiply with.... it could have been 8.73... so there is already a safety margin built in.... and the calculation itself will have included a safety factor for wear and tear, difference in quoted line strengths,etc. ( if such a calculation has ever been carried out, which I doubt )

the formula is probably correct for people built like brick outhouses who are pandemonium casting over grass but is probably twice the real figure for ordinary anglers using safer methods of casting.
It is one of those figures that has become 'fact' by constant repetition, ..... and has led to the lunacy of people insisting that heavy leader should be used when flicking a lure around on soft rods, or by people flounder fishing in the shallows.
 

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plus 10lb as a safety margin

that's the trouble when designing anything.... people keep putting on extra safety margins.

the 'calculation' is very unlikely to have come up with a value of exactly 10, it has been rounded up to give 10 which is easy to multiply with.... it could have been 8.73... so there is already a safety margin built in.... and the calculation itself will have included a safety factor for wear and tear, difference in quoted line strengths,etc. ( if such a calculation has ever been carried out, which I doubt )

the formula is probably correct for people built like brick outhouses who are pandemonium casting over grass but is probably twice the real figure for ordinary anglers using safer methods of casting.
It is one of those figures that has become 'fact' by constant repetition, ..... and has led to the lunacy of people insisting that heavy leader should be used when flicking a lure around on soft rods, or by people flounder fishing in the shallows.
The safety margin is designed for things like abrasion in your leader or hitting the ground during the cast .... the calculation could well have been 8.whatever and it could equally have been 10.4 in which case you might well be chancing your arm .... the lunacy comes with cutting corners and realising you got it wrong when its too late.

I don't think anybody here was talking about flicking lures but when you are flinging lumps of lead around on a beach you have to be pretty selfish to risk other people around you for the sake of 10 or 20lb of leader strength.
 

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I thought years ago they used to say for every ounce of lead 8lbs of breaking strain in magazines and books? I will say the modern rods are phenomenal compared to older rods and ok some of those were bloody good. Would a really powerful caster exert more load on a leader? someone must have calculated it at somepoint maybe the line manufacturers?
 
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