Author Topic: Adding weight to a SUP ...  (Read 16554 times)

PonoBill

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Re: Adding weight to a SUP ...
« Reply #30 on: October 22, 2014, 12:49:14 PM »
f = M a
 8)
Yes indeed, and given a force applied to the rail by chop, a heavier board will accelerate more slowly. The force required to correct the movement will be exactly the same in both cases--it will be equal to the upsetting force, but the counter force can be applied over a longer period of time.

Using cars as an example is a little flawed, the first compliance element in a car is the tires, and they react to a tiny unsprung weight--the amount of tire being deformed. But in all cases when designers create a luxury car, they don't build the wishbones out of carbon fiber unless it's for cosmetic reasons. Everything unsprung is pretty massive, and it's not just because it has to be strong and steel is cheap. It's because the natural period of a more massive wheel system is long, which gives a much smoother ride. Linter wants a Caddy, not a Ariel Atom.
« Last Edit: October 22, 2014, 12:57:00 PM by PonoBill »
Foote 10'4X34", SIC 17.5 V1 hollow and an EPS one in Hood River. Foote 9'0" x 31", L41 8'8", 18' Speedboard, etc. etc.

stoneaxe

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Re: Adding weight to a SUP ...
« Reply #31 on: October 22, 2014, 12:59:09 PM »
Linter doesn't need a masters class in vibration control to know that a heavier board feels good to him over a lighter one. This has NOTHING to do with sprung vs unsprung weight or even engineering.....it has everything to do with the subjective feel of a given board based on a given individual. The question isn't about what's better for performance light vs. heavy.....that answer has already been established......for Linter it's heavier.

There is obviously a difference in performance in heavy vs light.....not sure WTF the argument is about...Linter likes heavy and wants to experiment....sheesh.
Bob

8-4 Vec, 9-0 SouthCounty, 9-8 Starboard, 10-4 Foote Triton, 10-6 C4, 12-6 Starboard, 14-0 Vec (babysitting the 18-0 Speedboard) Ke Nalu Molokai, Ke Nalu Maliko, Ke Nalu Wiki Ke Nalu Konihi

PonoBill

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Re: Adding weight to a SUP ...
« Reply #32 on: October 22, 2014, 01:03:19 PM »
Hey, I'm just screwing off, trying not to write the next chapter of Riding Isabella, which is proving to be a slippery little bugger.

But while I'm in an arguing mood, for anyone looking to refute my claim about lead recycling, try here: http://www.epa.gov/wastes/conserve/materials/battery.htm  Lead-acid batteries are top of the list for percent recycled, both in terms of total recyclability of the material and percentage of the total production stream that is recycled. 98 percent of the lead, 96 percent of the total components, 97 percent of the production stream. Nothing else comes close.

I just figured out my problem with Riding Isabella--it's the title. The book is set in France, and should therefore be called Riding Anouk in honor of Anouk Aimee. I'm saving Isabella (Rosellini) for book three, which I guess has to be in Italy.

« Last Edit: October 22, 2014, 01:11:25 PM by PonoBill »
Foote 10'4X34", SIC 17.5 V1 hollow and an EPS one in Hood River. Foote 9'0" x 31", L41 8'8", 18' Speedboard, etc. etc.

Bean

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Re: Adding weight to a SUP ...
« Reply #33 on: October 22, 2014, 01:06:24 PM »

...much faster than the 20 lb board, which you have to pump like a short-boarding fool just to get close to the speed the older one gets with plain old point and shoot.
   that's what i'm after.


Linter, is it possible that some of the difference in speed is also attributable to rocker, plan shape etc.?  It almost sounds like you are comparing a traditional nose-rider to a performance long-board. 

And yes, this is a great topic.  I'm looking forward to hearing about your actual test results.

PB, I think you are perfectly capable of multitasking.

Subber

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Re: Adding weight to a SUP ...
« Reply #34 on: October 22, 2014, 01:16:38 PM »
f = M a
 8)
Yes indeed, and given a force applied to the rail by chop, a heavier board will accelerate more slowly. The force required to correct the movement will be exactly the same in both cases--it will be equal to the upsetting force, but the counter force can be applied over a longer period of time.

That is what I was thinking.  I think some don't realize that Linter wants a board that reacts more slowly to him moving about on it - to be more stable.  So the more mass, the more force it takes to move/change the location of the the board. - it will react a bit more slowly.
Jimmy Lewis Black & Blue Noserider 10'1"x31"x4.25," 164 liters, 24 lbs, 1 box
Pearson Laird Surftech Longboard 10'6"x23"x29.75"x18"x4.375," 154 liters, 24 lbs, 3 boxes
Takayama Ali'i II Surftech 11'x21.375”x28.5”x17.25”x 4.25,” 162 liters, 26 lbs, 3 boxes

supuk

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Re: Adding weight to a SUP ...
« Reply #35 on: October 22, 2014, 01:17:40 PM »
j-bird: i don't know the theoretical underpinnings of all this.  what i do know is that i have two boards that are the same length and the same width and roughly of the same shape.  one weighs 20 lbs.  i am very unstable on it, especially when there's any ruffle at all on the water.  moreover, on the wave, i absolutely hate the way it feels.  i'm a longboarder at heart.  i don't want anything zippy.  if i could attain elegance, that's what i'm after.  and the 20 lbs board offers me none of that.
   and then there's my 30 lb board.  a world of difference.  the utmost in stability in the roughest seas i personally will go out in.  plus, on the wave, it almost drives me crazy with happiness.  like honey, it just flows. and once in trim, it's faster than hell.  much faster than the 20 lb board, which you have to pump like a short-boarding fool just to get close to the speed the older one gets with plain old point and shoot.
   that's what i'm after.
   anyway, i'm obviously siding with bill here.  so, thanks, bill, for your response.  makes sense to me.  for my first go-out, i think i'm going to try one sheet of lead midway up near each of the rails, with a third sheet on the tail of the board.  it'll be fun to see what happens.
   btw / the lead sheets are about 3/32" thick.
   this has been a lively discussion!

personally it just sounds like your just describing two different boards, differences don't have to be huge to give the board a totally different feel its just you like heavy one which all good but i dont think that what you like is directly related to the weight.  Adding weight so it sits lower or taking out volume will make the board feel more stable in chop, aim to get the water line so it laps over the deck most of the time and you will get affected by chop and wind a lot less.

linter

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Re: Adding weight to a SUP ...
« Reply #36 on: October 22, 2014, 01:49:27 PM »
  it could be the difference in the two boards but i don't think so.  or at least the diff doesn't count for all of it.  i'll be able to tell as soon as i strap 10 lb of weight to the bottom of the lighter board.  the lead is supposed to arrive next monday.  will report back!

supthecreek

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Re: Adding weight to a SUP ...
« Reply #37 on: October 22, 2014, 08:13:49 PM »
Thanks for the replies to my sidetrack... it is an interesting topic to ponder during our current Nor'easter. Linterland is becoming a hotbed of weighty issues.

linter

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Re: Adding weight to a SUP ...
« Reply #38 on: October 23, 2014, 02:24:46 AM »
more like a hotbed of hot air, creeky.

meanwhile, a few final thoughts on weight.

1/ i'm an idiot.  you know that 20 lb board i kept comparing to a similar board that's 30 lbs?  i forgot (doh!) that all last winter i rode the ***exact*** same board as the 20lb one but it was 5 lbs heavier.  both are wardog hammers.  identical but for weight.  and the heavier one i preferred x 2 to the 20 lb one for all the reasons i've already stated about the 30 lb board (which i prefer to the 25 lb one x 2 as well).  wow.  the mind is a terrible thing to lose.
   the way i see it, that cements it: weight is the deciding factor, if only for the type of riding i do and the feeling i like to get from my boards.

2/ for what it's worth, i found this on another forum:
   "Eva Hollman, (boardlady.com)  once told me about an interesting mod with lead weights that she did on a surftech board.  At a customers request and since the board was in for repair anyway she put several lead discs in the center of the board in a row perpendicular to the stringer so that the overall weight of the board went up by quite a few pounds but the swing weight was mostly unaffected. She said the feedback from the customer was quite favorable."

 thanks again all for your input.  it's been both thought provoking and helpful!

SlatchJim

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Re: Adding weight to a SUP ...
« Reply #39 on: October 23, 2014, 09:01:17 AM »
But while I'm in an arguing mood, for anyone looking to refute my claim about lead recycling, try here: http://www.epa.gov/wastes/conserve/materials/battery.htm  Lead-acid batteries are top of the list for percent recycled, both in terms of total recyclability of the material and percentage of the total production stream that is recycled. 98 percent of the lead, 96 percent of the total components, 97 percent of the production stream. Nothing else comes close.
I would never want to get into a mental pissing match with PonoBill, mostly because I think my stream would eventually fall short.  Being a veep for one of the largest haz waste and recycling private companies in California, I was ashamed that I didn't know those percentages, and assumed that everthing was between 50 and 70 percent like aluminum and steel.  Good thing I didn't step into it. Bill is in fact a hair low.  Recent figures list lead acid batteries at 98% recycled.  My company recycles tons of waste batteries a year for local companies, I should have known more.

However, the position I have puts me in the crosshairs of a number of state agencies always looking to make headlines.  I guarantee you that if I strapped some lead on a surfboard, used it for a year, and tossed it in a dumpster, I'd be wearing conjoined steel bracelets in a matter of hours.  My caution and regulatory jitters often overflows to those around me.

pdxmike

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Re: Adding weight to a SUP ...
« Reply #40 on: October 23, 2014, 10:13:36 AM »
But while I'm in an arguing mood, for anyone looking to refute my claim about lead recycling, try here: http://www.epa.gov/wastes/conserve/materials/battery.htm  Lead-acid batteries are top of the list for percent recycled, both in terms of total recyclability of the material and percentage of the total production stream that is recycled. 98 percent of the lead, 96 percent of the total components, 97 percent of the production stream. Nothing else comes close.
I would never want to get into a mental pissing match with PonoBill, mostly because I think my stream would eventually fall short.
What do you do if you win a mental pissing match?  Yell, "WE'RE NUMBER ONE!" ?

SlatchJim

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Re: Adding weight to a SUP ...
« Reply #41 on: October 23, 2014, 12:34:49 PM »
What do you do if you win a mental pissing match?  Yell, "WE'RE NUMBER ONE!" ?

So this is what Bud Abbott felt like?

pdxmike

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Re: Adding weight to a SUP ...
« Reply #42 on: October 23, 2014, 02:07:19 PM »
What do you do if you win a mental pissing match?  Yell, "WE'RE NUMBER ONE!" ?

So this is what Bud Abbott felt like?
I don't think I even need to mention--if you get in a mental pissing match with someone, NEVER talk shit, or you'll end up number two.

« Last Edit: October 23, 2014, 02:12:34 PM by pdxmike »

peterwSUPr

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Re: Adding weight to a SUP ...
« Reply #43 on: October 23, 2014, 04:06:00 PM »
Wow, busy thread, I'm just catching up on this now.  Here's a thought that I don't think anyone has specifically stated.  If you like the WEIGHT of a heavy board then the mass distribution of the lead might not be too critical.  If you like the side to side stability of a heavier board then its the higher moment of inertia that you like.

On the heavy board that you like, there's probably more weight all over the board.  The extra weight in the middle does not add much to this. You can get a higher "roll" moment of inertia of the board (side to side tipping) by adding mass out near the rails.  The key here though is that if you get the right feel with 10lbs spread out all over the heavy board, if you weight out near the rails, all the extra wight out away from the center of rotation means that you won't need 10 lbs to get the same moment of inertia for side to side roll.  The moment of inertia is affected by the weight of the added mass multiplied by the distance from the center of rotation squared.  This makes a big difference.

This sounds like an interesting experiment, and if you can experiment with only about 5 lbs in various locations, (nose,tail, middle, rails, usual standing area etc) you might be able to figure out what property, other than just weight it is that you like the feel of, and you might achieve this without having to go to as heavy a board as you think.

Peter

stoneaxe

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Re: Adding weight to a SUP ...
« Reply #44 on: October 23, 2014, 04:38:28 PM »
Wish I had said that.... :D....what I was thinking about distributing the weight.....spread the moment. Weight will be more effective at the rails.
Bob

8-4 Vec, 9-0 SouthCounty, 9-8 Starboard, 10-4 Foote Triton, 10-6 C4, 12-6 Starboard, 14-0 Vec (babysitting the 18-0 Speedboard) Ke Nalu Molokai, Ke Nalu Maliko, Ke Nalu Wiki Ke Nalu Konihi

 


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