|i have been doing the math on the sacs available out there. they are all about the same weight and not what they claim. |
skylon claims 600lb: 20x50= 566 lbs.
-straightline claims 540 lbs: 20x50=566.
-get high sports claims big bump700-750 lbs: 18x66=606 lbs
-letsgoride v drive 500: 19x54=552 lbs but is not a true cylinder so 500 is probably accurate.
-fly high claims 600 lbs: 20x50=566 pounds
except for straightline and letsgoride.com, these companies are putting an awful lot of faith that you can hopefully stretch the sac to reach these weights. I myself do not believe it, especially if the bag is covered...
check the math if you want
radius x radius x 3.14 x length=cu. inches
the cu. inches / 1728=cu. feet
1 cu ft of water weighs 62.4 lbs
cu. feet x 62.4 = (false advertising with most companies).
|i think they just round it off |
|i agree but some of them round off pretty high. from about 540 to 600 would take 1 cu. foot more water which is a ton. the get high is rounding an awful lot.|
|i know that the sacs i have get real fat in the middle cause we fill em up full.|
The one I dont get is fluid concepts 1000# locker sac. They claim in a VLX it adds and addtl 300-400 lbs. I know they must of tested it but, in my boat, no way. The stock sac takes up all but about 12 to 18 inches of the locker. No way that FC pup adds that much more weight.
No possible way it adds that much.
|Well, if your locker were 3 feet wide by 18" deep and the sac extended an extra 18", that would be 420 lbs. |
So maybe it's not so impossible?
|the way i look at it, is in order for many of the sacs to reach 600 pounds, it would have to fit another 5 gallons. do you think you can fir a five gallon bucket within a sac after it is already completely full?|
Yeah, and if my aunt had balls she would be my uncle. She doesnt and shes not.
|old uncle dad??|
|I have been using one of these BG Wake Enhancer bladders in my BOW for years. It is a great bag. And, it can get HUGE. |
Bladder only is one $70!
|How are you doing your measurements, or are you going from the measurements from the manufacturer? I'm curious. Bags empty? filled? etc. |
There are several margins for error involved in measuring. I'm not saying you're wrong, and it's totally possible that companies may overrate their bags, but maybe they use a more accurate measuring method than you do. A scale perhaps.
|using their measurements... |
|I wonder how they measure then. Here's a thought: If they measure seam to seam, then they don't include what the extra space (green) where there is more potential weight. Most sacs weren't pefectly flat on the end, they're usually bowed out a little bit (i.e. green part). If they measure end to end and multiplied by Pi x R x R, then they're accounting for volume that isn't there (red). It would appear that most companys are only listing in their measurements the seam to seam (length) multiplied by the radius squared multiplied by Pi (blue). |
please excuse my crude drawing.
My theory is that most companys measure the sacs seam to seam, and tell us that they're smaller than they actually are, then they tell us that they weigh a little more than the actually do. They do this because what everyone ultimately wants is weight without losing space. I bet if you had the opportunity to weigh the sacs on a scaled they would be pretty accurate.
|maybe but 5 gallons of water is an awful lot to get to 600. |
the straightline says 540. skylon says 600.
they are the same size...
|I see what you're saying. |
maybe but 5 gallons of water is an awful lot to get to 600
From what to 600? Water weighs about 8 lbs per gallon.
|Fresh water- 8.33lbs |
Salt water- 8.55lbs.
Ty, my sacs stretch quite a bit.
Heh! I have a stretchy sac.
|Over a couple of beers my friend took a Skylon Phat Sac and filled it to capacity inside the bag. Then drained it out into five gallon buckets until empty. The result; 45 gallons of water. 45X8.34=375 lbs.. Of course they claim 500 lbs. I have seen in a magazine where the manufacturer had a claimed weight and a gallon capacity in the same sentence. For some reason they failed math as they were over 40 lbs off. Go Figure! |
Must be something like "magazine horsepower" were you build a small block by there ratings and it makes over 700 HP.
|You guys play with your sacks too much.|
|Pot meet kettle. Kettle meet pot. Don't make me tell them the tube story.|
|The middle of the Big sacks surpass the published diameter when filled. As well as the ends push into a dome Especially a uncovered sac such as a Get high sports one. I have no doubt that you can put an extra CU ft in the sack past the published measurments, we do it all the time. Most of use don't pack the sack as tight as it is possible. They round uo for convience. As for same size sacks with different publish weights, thats more for marketing|
|Hi Ty. On a related subject, how do you know you have 900 lbs in the bow locker? Did you guys measure the locker and calculate the volume? Or are you going off the sac dimensions? Or did you weigh your boat? Just curious. Thanx.|
|actually it is only 700 pounds. from the measurements, it is 727 before stretching and the lgr sacs do stretch pretty good. i figure we loase about 25 pounds in taper in the bow.|