Author Topic: Board width variable  (Read 10532 times)

sterbo

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Board width variable
« on: March 04, 2015, 02:15:29 PM »
Curious what the consensus here is as to what an acceptable deviation from a given board manufacture's width specification would be.
For instance, my SIC Bullet 12 6 is specced at 28.25 inches but is actually 28.75.
In addition to the website specifications, the bottom of the board is imprinted with length, width, volume. Both the website and board call outs are consistent.

Seems to me, for a board of this type and cost, the tolerance would be much tighter - perhaps .25 +-

Thoughts?

SlatchJim

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Re: Board width variable
« Reply #1 on: March 04, 2015, 02:36:19 PM »
It could be in imperial inches...

There's a $100,000 joke there somewhere.

pdxmike

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Re: Board width variable
« Reply #2 on: March 04, 2015, 02:48:03 PM »
28.75 is less than 2% greater than 28.25.  Personally I wouldn't be concerned until a difference got large enough it would influence performance so much that I'd choose a different board, and 1/2" doesn't seem like that big a deal.  Plus width is the easiest thing to measure on a board.  Rocker, rail shape at any given point, width at any point other than the widest, thickness at any given point, etc. could all vary lots from board to board and nobody would ever know since those measurements aren't typically given and they're even hard to measure from board to board.  And from what people have said volumes often are quite a bit different than advertised, but they're difficult to measure.  So a 1/2" difference isn't something to dismiss entirely, but on the other hand two boards that are 1/2" different in width might be more similar overall than two that were exactly the same width. 
« Last Edit: March 04, 2015, 02:54:09 PM by pdxmike »

TallDude

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Re: Board width variable
« Reply #3 on: March 04, 2015, 03:16:16 PM »
One typical race or touring board can have a different 'water line' width depending on what the weight applied to it.  Unless the rails are a straight up and down 90 deg angle, the outer most wetted surface line will change. So where would you measure width it if the rails curve? I'm 240 lbs so most board would probably measure wider at water line. Maybe SIC puts 180 lbs (average male paddler) on a board and measures the waterline?
It's not overhead to me!
8'8" L-41 ST and a whole pile of boards I rarely use.

sterbo

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Re: Board width variable
« Reply #4 on: March 04, 2015, 04:03:29 PM »
As I understand it the measurement of the width is taken from the widest point, fore/aft and at the outermost point (apex) of the rails.

That said, and just to clarify, I'm not concerned about a half inch (in this case) or so regarding performance. My question is really just academic insofar as typical board construction is concerned.

Most boards, with the obvious exception of those that are truly custom, are fabricated via CNC. All of the components - glass, carbon, etc. are a reasonably known quantity therefore the whole of the assembly, in this case width, should result in a spec that's virtually dead on - hence what I, as a building contractor would consider to be .25

TallDude

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Re: Board width variable
« Reply #5 on: March 04, 2015, 06:34:38 PM »
When you CNC a board, you still have to finish sand it. Depending on the cutting head or cutting wheel, and how many passes the machine makes, there can be a lot of sanding/ detailing left to do. Depending on who detail sands it, you will end up with varying dimensions. BTW, like myself, there are a lot of contractor / amateur shapers on this forum. Some not so amateur.

We allow 3/8" tolerances here..   
It's not overhead to me!
8'8" L-41 ST and a whole pile of boards I rarely use.

supsurf-tw

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Re: Board width variable
« Reply #6 on: March 04, 2015, 06:37:43 PM »
One thing to realize is that the stated dimensions are shaped dimensions so after glassing things will change generally a bigger number
Boards:

 
8-10 x 31 Egg
8-11 X 32 Double wing Fangtail Tom Whitaker
8-6 X 30 1\2  Inbetweener Tom Whitaker
8-4 x 30 Hyper quad Tom Whitaker (wife's now)
8-4 X 31 1\4.  Round (wide) Diamond Tail Quad Tom Whitaker
 9-4 X 30 1\2. Swallow Stinger Quad Tom Whitaker (ex wifes now)
10-0 Brusurf for teach

Area 10

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Re: Board width variable
« Reply #7 on: March 05, 2015, 12:00:25 AM »
Curious what the consensus here is as to what an acceptable deviation from a given board manufacture's width specification would be.
For instance, my SIC Bullet 12 6 is specced at 28.25 inches but is actually 28.75.
In addition to the website specifications, the bottom of the board is imprinted with length, width, volume. Both the website and board call outs are consistent.

Seems to me, for a board of this type and cost, the tolerance would be much tighter - perhaps .25 +-

Thoughts?
We've had this issue before with SIC and other brands. The X14 used to be advertised as 29.5" wide I think, but is actually 28.75" wide, as far as anyone can tell. After this was pointed out on this forum, Flow Sports (who distribute the SIC production boards) changed the advertising material.

More recently, Starboard appear to have even a bigger inconsistency between actual and advertised widths with the Ace GT 17fter. The inconsistency there may be several times bigger than the one you are discussing.

In general, it seems that advertised widths of SUPs are rough guides, rather than guaranteed dimensions. Brands tend to round up or down their numbers, according to what they think will sell best. And then some advertised values are typos. And some might just be outright marketing flim-flam. Some boards aren't even the advertised length. For instance a SIC Bullet V1 14 is actually closer to 13ft 10" if measured the same way as yields a 14ft length for the Bullet V2 14.

If I am demoing a board now and really want to know it's dimensions I take a tape measure with me. It's hard to get a very accurate measurement that way but at least I rule out the worst examples of disinformation.

There seems to be wide spectrum of opinion as to how annoying it is to be misled by claimed dimensions. Personally it bugs the hell out of me when I'm told something that is patently untrue. But many other people seem to not care much. And of course then there are the brand fanboys and dealers who will defend their brand no matter what.

I like SIC boards a lot. I own three. But I think that Flow Sports probably take a rather casual attitude to describing the dimensions of them. I'm pretty sure that if your ordered a custom board from Mark Raaphorst and asked for it to be 28.5" wide, then that is what you'd get. So it does puzzle me that this isn't the case for many brands' production boards. But as I say, many people just don't seem to care, even though they might be the same people who would make a fuss if they were served a beer that was smaller than advertised. Go figure.

PonoBill

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Re: Board width variable
« Reply #8 on: March 05, 2015, 12:59:16 AM »
Generally in hand-built consumer composites a five percent variance is considered acceptable and two percent is good. The variance in your SIC example is 1.77 percent. While "production board" sounds like something extruded from a glopita-glopita machine, these are actually hand built, meaning a CNC-ed blank is sanded and then laid up by hand. there are no molds involved. Most of the production boards are built this way. the boards with more advanced sandwich construction involving multiple layers are even more prone to variation in dimensions and weight.

Conversely, the hollow SIC boards hand built on Maui are built in molds, so the tolerance is tighter.

Last, but not least, there are no industry standards on where and how width is measured. It's often a fairly casual thing.
« Last Edit: March 05, 2015, 01:04:27 AM 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.

Area 10

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Re: Board width variable
« Reply #9 on: March 05, 2015, 02:30:25 AM »
Ok, so let's have a go at answering the OP's question about consensus. In general, is there anyone out there who would strongly disagree with the following, and assuming the board width is straightforward to measure (some designs aren't)?

Actual width up to 0.5" wider or narrower than advertised: to be expected.

0.5"-0.75" discrepancy = not great, but don't call the cops.

0.75-1.0" discrepancy = should do better.

1-2" discrepancy = the retailer might start to listen to you if you wanted to return the board as not as advertised.

2" or over discrepancy = the board width isn't as advertised.

eastbound

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Re: Board width variable
« Reply #10 on: March 05, 2015, 04:53:45 AM »
more concerned re weight discrepancies, and failure of some manufacturers to publish weights
Portal Barra 8'4"
Sunova Creek 8'7"
Starboard Pro Blue Carbon  8'10"
KeNalu Mana 82, xTuf, ergoT

supthecreek

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Re: Board width variable
« Reply #11 on: March 05, 2015, 06:14:38 AM »
I am NOT a race board guy.... but inches matter to me.

2" isn't even in the same game.... let alone ballpark.... heck 1" can be the difference between love and hate.

as I re-read this, I can hear the snickering from my house  ;D



PonoBill

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Re: Board width variable
« Reply #12 on: March 05, 2015, 08:55:39 AM »
I think that's pretty much right on Area10. Width and thickness are harder dimensions to hold within tolerance. For a 10' X 30" board a two percent variation is 2.4 inches in length and 0.6" in width. Moreover, more people care about length being accurate than width, and almost no one is going to measure the thickness. You can expect what you inspect--that works for the market in general as well as individuals.

Weight variation is very substantial. Ke Nalu paddles blades and handles are made in precision aluminum molds, and the shafts are wound on tapered aluminum mandrels. The weight variation when I was associated with the company was ten percent with the occasional flyer on either end that went beyond that.

The folks trying to set rules for SUP racing have gone so far as to specify where width should be measured. If anyone paid attention to them the design of raceboards would be even further compromised and even further favor light paddlers since design would then devolve to making the most out of a rigid width-forward design template.
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.

pdxmike

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Re: Board width variable
« Reply #13 on: March 05, 2015, 10:14:26 AM »
It could be in imperial inches...

There's a $100,000 joke there somewhere.
I believe there are 36 imperial inches in a Scotland yard.

pdxmike

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Re: Board width variable
« Reply #14 on: March 05, 2015, 10:46:35 AM »
Ok, so let's have a go at answering the OP's question about consensus. In general, is there anyone out there who would strongly disagree with the following, and assuming the board width is straightforward to measure (some designs aren't)?

Actual width up to 0.5" wider or narrower than advertised: to be expected.

0.5"-0.75" discrepancy = not great, but don't call the cops.

0.75-1.0" discrepancy = should do better.

1-2" discrepancy = the retailer might start to listen to you if you wanted to return the board as not as advertised.

2" or over discrepancy = the board width isn't as advertised.
Area10--I also think you summed it up well.  Plus your comment about rounding is important.  It doesn't make much sense for a company to state a width in increments smaller than 1/4", so the actual size might be up to 1/8" off from that if measured exactly.  Add another 1/8" margin of error or rounding in taking your own measurement (and 1/8" is a very small amount) and the difference is already up to 1/4", and that's just for measuring the same individual board. 

 


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