I’ve had big wave leashes break on me anyway. I read that a leash can be about 4kg of drag. How’s about reducing that a bit? Glass the tail heavy to reduce the rail saver, perhaps? Use weaker leashes and replace every 50 stretches, say?
Any way to relate board design to the leash? Have the leash out of the water somehow or anything?
Have the guys at “Stay Covered” tie you a “Calf Leash” in their big wave leash material. Then install an extra leash plug(that would be two). Attach the leash with two strings. One to each leash plug. Some of the Calf Leashes have a leader at the calf that is stiff and helps to hold the leash up and away from the board and water(drag). Got to be some other reason that you are going thru leashes. Buy a better or best quality leash and make sure the string that attaches it to the plug is good quality string or Parachute Cord. Buy a new leash every season when Winter surf starts to show. I am also wondering what type of board you are riding? If you’re like our Inland Portlanders up here in Oregon; You would be riding a heavy “Boardworks” longboard in overhead surf. If that is the case no leash will hold up in double overhead surf.
Umm, I tend to doubt that 4 KG drag number. You’d notice that much as a pull on your leg.
Put two 2 kg bags of sugar in a shopping bag, sit down in your comfy chair, put your foot through the straps and do a couple of leg lifts. Right, that’s substantial. You’re not feeling that while you’re surfing. Here,in some seasons, we have an algae we call ‘mung’ that catches on leashes and causes substantial drag, but even then ( haven’t measured it ) it’s not that kind of drag.
If you want to test it? Get a fishing scale and find a fast-moving stream - want to have some fun? Test one of those curly leashes versus a straight one.
Typically, unless you’re attaching the leash to something on the bottom like your fin screw ( don’t) . pretty much all of the leash is gonna be skittering along on top of the water, minimal drag. I wouldn’t worry about it. The only time you feel the leash pulling is when you fall and the wave takes your board. Which brings is to-
Heavy leashes versus light ones. A little physics and engineering theory here - Hooke’s Law: F=kx*, where F is force exerted on a spring ( your leash) , k is a spring constant for that spring and x is the length that you compress or stretch that spring…
Still with me? Okay, now, the wave takes your board and exerts force F on it. How far it goes is governed by two things, the spring constant k of that particular piece of urethane strand that makes up your leash and just how long the ultimate stretch of it is before it stops stretching and then breaks. A thin leash of a given length will stretch further with a given force than a thicker one, as you might guess, but it runs out of stretch easier. You can make up for that by making your thin leash longer. But eventually you get to where you have a helluva long thin leash that really does drag quite a lot and it’s stretchd long enough that you’re a danger to people paddling out.
And oh yeah, that thinner leash has a lower strain to its ultimate stretch and it’s easier to break. Typically you have a leash stretching as far as it will go and then it kinda hangs there if it’s in perfect condition…but they never are. You wrapped it around the tail of the board to carry it, it got a little abrasion from your fin or fins and that’s where it breaks.
Oddly enough, a trick climbers use to see if their lines are starting to go is to run their lines across their lipe- wear and abrasions and loose strands can sometimes be felt and its time to replace the line. Lips being more sensitive than fingers.You might be able to pick up abrasions on your leash the same way.
Which is why you have heavier leashes. k goes up. They take up the same force without the board going halfway to the beach. Typically they take more force to get them to their ultimate stretch and unless your dog chews on 'em, they take more to break. You feel more pull on your leg. You pays your money, you takes your chances.
Rail saver drag - pretty much nonexistent. unless your rail saver used to be a twelve foot hoisting strap. It’s a flat piece of synthetic webbing that (again, unless it’s attached to your fin somehow) will skitter on top of the water and the drag is negligable.
Okay, you’re still concerned about it? Some others are too, though if there’s any reason to is questionable… Which is how the surf accessoies people manage to sell the ‘longboard leashes’ that go around your leg higher up rather than your ankle, holds the leg end of said leash up higher out of the water. You may find you’re more prone to getting said leash tangled around your feet - again, you pays your money…
hope that’s of use
doc…
*****Robert Hooke was a physicist among other things and a good one who made serious contributions to our understanding of mechanics, optics and a whole lot more. Issac Newton hated him with a passion ( Newton was a very strange man and something of a prick) and did his best to suppress and discredit Hooke’s accomplishments and discoveries. Look him up.
Or you could buy a floating leash , they dont all sink .
You see leashes skipping across the wave in videos. They spend a lot of time in the air.
But this slightly off topic response is to highlight a very real instance of drag.causing a problem.
I installed one of the early Shark shield devices about 10 years ago. There is a device that plugs into a tail pad on the board and trails a 6’ aerial out the back. This aerial is some 1/2" in diameter and weighs around 1/2lb. You can actually feel the drag when you are paddling and sometimes when you are riding.
I was surfing pwerful 6’ barrelling surf and pulled into one, got a bit high on the face and went over the falls. The lip got the board and exploded it into two.
I’m convinced that the drag of the sharkshield aerial put the board into the sitation where it was in the power of the lip that snapped the board.
Modern versions of these devices have the aerial glued into the board.
I disagree with the premise of the opening post. I know from my own experience that there is no noticable drag pulling on the back foot when you are up and riding a wave. From a practical standpoint the leash is skimming and dancing on the surface of the wake created by the board or is nearly airborn. If anything, the only area where leash drag is of any issue at all is when paddling the board. To that I say, get fit.
I’ve gotten into surf photography a bit in recent years so I took a peek through some recent shots to see if I could find any that illustrate the leash in motion.
This shot of my son illustrates it pretty well. If you look closely you will notice that the lower portion of the leash is skimming along on top of the water in the wake caused by the board displacing water. You will even note that the leash is not stretched tight on either the half attached to the board or the half attached to his leg. If there were drag being exerted on the leash while up and riding the leash would be stretched tight.
Well observed, and well stated.
It looks like there should be no drag… Anyway, this is special situation, but when surfing straight on a tidal bore (with longboards or sups), and you have time to feel things over several minutes on the same wave and the wave gets weak at some points, many people (including myself) are pulling their leash out of the water once standing, because the drag is very noticeable : less speed, foam on top of the wave, the leash is not bouncing on top of the water as on the photo but more under water.
In the attached photo, 2 out of 4 surfers hold their leash in their hands, and the difference is very noticeable. So I would say it depends.
