What is more important?

You have 3500.00 in your pocket and are ready to buy a new boat. What is more important, The weight of the canoe? Or the Quality? From a performance standpoint I think we can leave the "my boat is best" out of this argumant. No boat is best, The paddler makes the boat. So having said that I am curious how much stock we put into the weight of the canoes, Some builders are making very light boats that require you to be extra careful with the boat to keep from dinging them, or having structural issues. Others are building a boat that will last many more years. In a sport that has no financial incentives, is having the lightest boat possible really that important? Where do we draw the line between going as fast as possible, and having quality products?

Submitted by OceanOhana on Mon, 11/26/2007 - 12:14pm



I bang my boat on everything no matter how careful I am. I get dings when I don't even remember banging my boat. I'd rather have a better built boat than a few pounds light. Plus when I'm 4 miles offshore I'll feel a little bit better about being 4 miles offshore.

I had a friend whose boat split on the seam 2 miles off portlock. He had to swim for 2 hours in the dark.


#1 Mon, 11/26/2007 - 1:58pm


Ohh if you didn't catch it in my first post I bang my boat all the time. I don't even remember banging my boat but I guess I bang it all the time. Bang.

Poopie


#2 Mon, 11/26/2007 - 1:59pm


I dont think 3 to 5 lbs. one way or another makes a boat faster. A slightly heavier boat is probably going to last longer ,assuming the seams are strong . A while back in one of these threads people were talking about the difference between the 200 lb. Mirages and the 400 lb ones. Someone said that the 200 lb boat accellerated well but, lacked glide.
I find this to be true with the one man canoes too. I have 2 double carbon Fuzes built by Karel in Hawaii and several Chineese built Fuzes , the weight difference (3 or 4 lbs) is noticeable when you pick up the boat but in the water it
s very hard to tell the boats apart. Also , the pure carbon boats require alot more care when ground handling, loading , unloading onto vehicles.


#3 Mon, 11/26/2007 - 2:37pm


Damn Fuzerider, you ARE THE Fuzerider.


#4 Mon, 11/26/2007 - 3:12pm


I have to have the fast canoe and have half a chance to race with the big boys. And a lighter oc has that little bit moor. Know the training has the biggest part to racing but the bells and whistles on a boat really makes that little difference if you believe in your canoe is important and to have the best paddle you cane get. If that is what you want. I guess what I’m saying is you have to put as much training in as you put $ in you equipment. So yes I would say get the lighter one...


#5 Mon, 11/26/2007 - 4:16pm


I'd go with quality over weight if funds are limited and you are restricted to buying one canoe. Equipment failures or failures in design will really detract from your paddling experience while durable canoes will give you years of relatively pain-free runs. Soggy or hole-ridden canoes or canoes with ill fitting pieces are no fun either. Think about buy a lighter canoe when funds permit.

I had a buddy with two of the same canoes. One was an ultralight designed for one season of competition. The boat was delicate but was awesome in performance compared to stock which goes to show you that the "I'm 245lbs. Weight doesn't matter" argument is not necessarily or entirely true....but that's another argument.


#6 Mon, 11/26/2007 - 5:39pm


Quality and lightweight are two completely different issues. A quality engineered and constructed boat should be safe in all ocean conditions for which these craft are reasonably expected to see regardless of weight.


#7 Mon, 11/26/2007 - 5:51pm


Isn't the real goal for any builder to give you both light weight AND durability? I guess the old adage is true: durability, light weight, or inexpensive - you can only choose two.
Lighter boats have relatively better acceleration at the expense of a more consistent glide, but the advantage gained by that extra "glide" in a heavier boat just doesn't make up for the extra 2-4 lbs. pulled over the course of 8 - 20+ miles. Lighter IS faster.
Find a builder you trust, with good customer service and communication. Then buy the lightest boat they make that fits into your budget. They should be completely up front with you about any durability issues, and what to expect from contacts and collisions, both on land and in the water.

All that being said, in the quest for lighter weight, just concentrate on losing some of that 5 - 10 lbs. of holiday excess on your belly, butt, hips and thighs. THAT'S the cheapest way.


#8 Mon, 11/26/2007 - 7:01pm


o ya, carbon is stiffer and that translates to speed. But I get what you mean by cost. it makes no sense to have the high end canoes especially if you translate it to rent or groceries. but sometimes in life you have to make mistakes and what a mistake. I had a hurricane for a season sold it [crack's] . I’m 225 lbs . recently slid into a Pegasus[nice...]. I’m trying my best not to regret it, but I can't whip this smile of my face.

peac


#9 Mon, 11/26/2007 - 9:53pm


Billy Robello always paddled a 23-24 lbs. boat. It’s ironic because his customer would want the lightest boat he could make and yet he would go out every week and be top 3 in a heavy boat. He always said a light boat is good but stiffness is more important. He always put stiffness ahead of weight Then again very few boat builders actually use there boats, and he would pound his up the wall four times a week, and does Makapu`u runs in conditions most of us would call insane.


#10 Mon, 11/26/2007 - 10:17pm


holy smokes, i think someone else found the google translator.


#11 Mon, 11/26/2007 - 10:29pm


water, canoe, paddle, me,= traslates to the perfect day


#12 Mon, 11/26/2007 - 10:39pm


^^ Yawn, only when the ocean turns white.


#13 Tue, 11/27/2007 - 7:54am


Theres another angle.....what if you could have a 15-17lbs hull that is stiffer, and stronger and more resistant to dings..........
but cost $1000-$1500 more. Its doable, but is there a market?


#14 Tue, 11/27/2007 - 8:36am


I agree with Goto. I see guys stress about 2 or 3 lbs of extra weight on their boat, but who could easily stand to lose 20 or 30. Skip the next two burgers and buy the more durable boat. Then when there are no other variables standing in your way, go for the lighter boat. You can only buy so much speed. Eventually, you have to train.

The above opinion is in no way meant to imply that I, myself, have done this.


#15 Tue, 11/27/2007 - 8:40am


tough choice.............


#16 Tue, 11/27/2007 - 9:51am


if it takes a while to make the choice maby not?

holly smoking yawn^^^^


#17 Tue, 11/27/2007 - 5:29pm


here is a little data for you, Using a Fuze that has a hull weight of 26.8 lbs with seat and rudder, I did 8 .15 mile sprints with a rest time of 1 min 7 seconds on average. I did a about 11 minute / .9 mile warm up that included two .15 mile sprints. I took a 5 lb weight that was attached to the seat and placed it on a floating platform, I then did eight .15 mile sprints, Sprints 1,2 and 5, 6 had regular hull weight. The 3,4 and 7,8 had the added 5 lbs. The conditions were pretty perfect for this testing, Open bay, no wind no tidal flow, No chop. deep water.
Here are the numbers.
Max speed w/o weight 7.7 max speed with weight 7.9
Fastest Time, W/o weight 1:21 with weight 1:21
Max Heart reate w/o weight 178 with weight 177
The averages
W/o weight Time 1:22 Max Speed 7.63 HR Ave. 156 max 173
with weight Time 1:23 Max Speed 7.7 HR Ave. 160 max 174

I also did two .68 mile runs one with one without the weight.
Time without weight 6.08 max speed 7.3 Ave HR 172 max 181
Time with weight 6:13 Max speed 7.2 Ave HR 167 Max 178

A lot more data needs to bo collected, I would love to see someone else do the same type of testing, Longer pieces, maybe a larger weight,

You can see all the data at this link
http://trail.motionbased.com/trail/invitation/email/accept.mb?senderPk.p...
The first test sprint without weight starts with Lap 4.

Have fun with this,


#18 Fri, 11/30/2007 - 6:15am


so what was the conclusion?


#19 Fri, 11/30/2007 - 6:51am


Not sure yet, I was however surprised that the numbers were so close. I also kept track of the number of strokes it took, I tried to keep the same amount of strokes per side, Starting 20 each side for first two side, then 15 for two, then 10 after that. I noticed when the boat had extra weight I id the .15 distance in 90-92 strokes, with the unweighted canoes it was closer to 96 strokes. My guess is this has to do with the momentum, This can also be why my absolute fastest speed at 7.9 was done while the boat was weighted and on my last run.
I think the best test will be longer 1 mile repeats. where you get more into a rythem that wilbe more like long races than the sprints. One thing I forgot to add, The last two long pieces the start was a moving start rather than from a stand still.
In the future I want tto repeat the test with someone timing rather than hitting the lap on my own, also to start times with a boat already at speed to take the stress of teh start out of the equasion. This i think will also better simulate real paddling. Unless of course we are trying to determin exceleration.


#20 Fri, 11/30/2007 - 7:04am


catching up on some of the recent interesting posts, a few things are
apparent:

(1) like many equipment intensive endurance sports, there's a
pathological concern with weight
(2) there's a lot of great boat building expertise posting here
(3) poopoo, goto and gang are witty goons, funny, but goons all the
same

so a long winded question for the physiologists, boat builders and old timers...

if you shave 6lbs off a 28lbs canoe, you reduce the weight by ~21%. sounds impressive... however... the boat doesn't move without the paddler. i weigh 180lbs (cause i have 5+lbs of beer gut right now, gotta go back to pot, but only in low fat olive oil based brownies so i don't hurt the lungs). so, 6lbs off boat + paddler (208lbs total) is actually less than a 3% reduction. 6lbs of body weight is also 6lbs of metabolizing slob... it takes a cut of oxygen every breath and wants some grinds too. additionally, fat is a little less dense than water, so 6lbs of blub is somewhat more than 4"x4"x10" of additional body volume through which the heart must profuse blood every stroke. extra body weight isn't simply a matter of extra mass fighting gravity. a 6lbs linear addition to boat weight, on the otherhand, can have a cubic effect on volume, most of which is air, which greatly lowers density of the boat+paddler combo without cardio-pulmonary strain, which improves buoyancy. in a boat moving water out of the way is a bigger deal than the work of moving away from the earth's substantial gravity (the latter captured nicely by F=m * g * sin(theta) times distance to make it "work" in the physics sense, but on water theta is often close to zero, at least along the vector between start and finish lines)... more buoyancy, less hull in the water, lower planing speed, less electrostatic friction between hull and water, etc... unless, maybe, you're one of those people frequently paddling large, long period swell (let's take 6'@14seconds-- not untypical for many parts of the pacific), in which case you may actually be paddling uphill quite a bit... a 14s wave is about 1030' long, roughly half uphill... 6'/515' is on average a 1% grade, pretty shallow compared to huffing up the typical cinder cone beer gut in tow... but the wave's steeper near the peak of course, which can certainly bring a boat's speed right down as we all know. furthermore, a 14s wave is moving at about 22kts (this isn't coincidental relationship since speeds of the wave generating wind sets wave period, or length if you prefer). so to think about either coming to a stop near the crest, or to begin surfing coming down-- to surf coming down you need to not only reach an ideal planing speed, velocity needs to be in addition to the 22kt wave speed (since one is outrunning the water). obviously gravity plays a pretty big role near wave peaks where sin theta is much closer to 1 and the boat+paddler mass and earth's gravity are fully interacting... which hurts going up when F is human generated and doesn't make a difference coming down when g (acceleration here on earth) is dominated by the planet's mass... and anyway this isn't the case for the majority of a a paddle run or many paddler's typical outings. the main affect of weight in a typical run is how much it causes a boat to sink and cause drag, and that's better modeled as functions of pressure, surface area, density... not strictly weight.

all this to say the world is complicated and weight a pretty crude criteria... and why we can get our asses kicked by guys/gals with heavier, cheaper boats. oceanohana... nice experiment. i'm also curious about the following. the general belief is that malias are heavier and thus slower (though it's certainly not like malias come in last place behind every fiberglass boat!) my guess is that any slowness comes from their density, er... weight/volume. if i actually cared to really know, i'd like to look at an unloaded malia next to a comparable fiberglass boat. it would be nice to do in a small pool where displacement of the water could be measured (of course an unloaded, stationary boat is really a partial story). my guess is that the malia just rides lower in the water, ie. more drag. so, basically, i'm skeptical of this momentum theory of glide vs acceleration in a boat given small percentage mass change of paddler+boat. maybe when going from a 100lbs boat to a 30lbs boat, but not 30lbs boat to a 24lbs boat.

so, with advent of lighter building materials, i wonder how much of the advantage has been simply to shave mass, which i'm guessing within a few percent is really only substantially beneficial near the crests of waves, versus keeping weight the same and increasing hull volume in an effort to get boat plus paddler out of high friction, high drag water?


#21 Fri, 11/30/2007 - 7:26am


Very interesting. At first glance I would say perhaps, knowing youre weighted, you pulled harder. But that wouldnt account for a lower heart rate. Very very interesting.


#22 Fri, 11/30/2007 - 7:29am


I would say quality but weight is in the decision. maybe tested in a pool with a motor and not a man and timed precisely and scientifically in a controlled environment or maybe just watch the races and see which wins moor. I thought at one time which feel right but
when I took my Pegasus for a test run I didn’t care for it and the next day I kept thinking about it and how it felt and preformed and went back an got one. and now I love it.
hmmm?


#23 Fri, 11/30/2007 - 6:56pm


Donald.....no ack.


#24 Fri, 11/30/2007 - 8:14pm


I have paddled both a 35 lb fiberglass version and 26 lb carbon version of the same boat. It makes a difference, a big difference. There's more to it than just linear motion and water displacement. The heavier boat has increased angular momentum and is less responsive on all axes. The cumulative effect when surfing downwind is remarkable and immediately obvious.

Name calling is pointless. Regardless, these pompous, long winded, "Dennis Miller"-esque, stream of consciousness diatribes are very tiresome.


#25 Fri, 11/30/2007 - 9:04pm


solid and light will always beat heavy and flopie?


#26 Fri, 11/30/2007 - 9:01pm


haha poopsie and goto, he called you goons... and you're all the same.

serves you right!

The Malia argument holds water, errr, displaces, anyway.

ILH teams race in Malia's all year, then whup everyone in High School State Championships. Are they in effect using resistance training? Especially since during the state regatta, Mirages are used. Ah but never mind, cause when the ILH is the host conference, they make everyone race in Malia's, and the result is the same. Dang, thought I had something there.


#27 Fri, 11/30/2007 - 11:28pm


What is "angular momentum"?


#28 Sat, 12/01/2007 - 8:24am


Whitewater good question:

http://en.wikipedia.org/wiki/Angular_momentum

Basically adding 10 lbs to a rider can't be equated to adding 10 lbs to a boat, because the rider's mass is all located near the boats center of mass and the 10 lbs added to the boat is averaged over the whole 20 ft length. Imagine holding a 20 foot pole in the middle and swinging it up and down and left to right. Now imagine adding 2 lbs of weight on each end of that pole and doing the same. It's not that much weight but when you consider the long lever, the effect is very noticeable. So when the boat is heavier, not only is the rider dealing with accelerating the additional mass, but also dealing with a mass that is more resistant to changes in direction.

A more dramatic, but much less analogous example would be adding a gallon of water to the hull vs. adding a gallon of water to a pack on the rider. The effects of that 6 lbs of water sloshing to and fro inside of the hull will have a much greater effect on performance than the 6 lbs of water tied to the rider.


#29 Sat, 12/01/2007 - 2:56pm


One article mentioned that there is a downward limit for boat weight.

It stated that for every paddler's specific weight a boat has an ideal weight; but that weight was not necessarily the lowest weight possible.
When the boat gets too light for the paddler, other factors such as vibration of the hull start to matter.

So I'd take the lighter boat, but not the lightest.

BTW, I recently saw two Hurricanes open - belly surgery.
One had a 'paperthin' hull near the foot wells, the other one had a really strong hull. Maybe one was once made for special competition, maybe they experiment over time how to do the hull, I do not know.
But I'd take the sturdy one in this case.


#30 Sat, 12/01/2007 - 3:15pm


hi kd... let me eat crow and offer my apologies to you.

i feel truly badly if you took offense. given the jeers, taunts and regular unfriendliness offered up by some here, i hadn't suspected that my seemingly mild epithet that i thought i had rolled into what was in fact a compliment ("witty" and "funny") would have bothered the seemingly thick skinned folks it was directed to or that i had crossed the lines for community norm.

you are absolutely, 100% correct. name calling has no place and my word selection poor. my observation that a few of the most frequent posters have little hestitation in ruling their playground by ganging up and serving it up in spades to those who have different ideas, opinions, or that they just plain don't like should have been given not in a noun but in an adjective as "goonish".

if we ever meet, if you allow, please, beers on me (assuming you're a drinking man).


#31 Sat, 12/01/2007 - 7:43pm


hey... kd... i almost feel this should go in a private email, but what they hey. you seem like a charger and someone as comfortable with calculus as algebra and probably have an interesting comment on it... i've thought a bit about your good point on angular momentum...

here's something i don't understand about angular momentum, perhaps you can help? angular momentum is given by:

L = m * r^2 * angular_velocity

but, in fact, this is for an ideal point. a better model of a real object would require summing all the mass "points" along the object from the radius to the outside edge. so for instance, if for simplicity sake we thought of a canoe as just a rectangler 20' log, the 30 lbs boat is 1.5lbs/ft and the 20lbs boat 1lbs/ft. using whatever favorite numerical method for reimann sums, with radius playing a much bigger role than mass and angular velocity equal for the two logs, it looks to me that the angular momentum of a 20' 20lbs log is about the same as a 30lbs 16.25' foot log. of course, a canoe isn't shaped like a log, the bow and stern have pretty small circumferences and don't carry most of the mass (which is towards the center of the boat). so, ballpark without doing too much multivariate math... the angular momentum of a 20lbs 20' boat is about equal to a 30lbs 19' boat. maybe you can make a suggestion on my thinking here?

definitely, you're right... abstract models aside what counts is what you feel with the boat and i definitely always found the carbon fiber stingray easier to lift back on the rack than the comparable fiberglass model i have used. on the water? i'm not quite as sure about it as you.


#32 Sat, 12/01/2007 - 7:56pm


Oh how I love the scientific point of view! The thing is, the more important stuff is spiritual/emotional. Any observatiuon of a top team will lead to this conclusion,


#33 Sat, 12/01/2007 - 9:13pm


Donald, I did another rough estimate. If you consider that angular momentum can be defined as:

L = Iw

where I is the moment of inertia and w is the angular velocity and we only consider rotation of the canoe up and down -- ie the axis that runs from your left side to right side as you sit on the canoe -- we can make an estimate of the angular momentum without much calculus.

The I value for a hollowed out cylinder (see wikipedia) is linearly dependent on the mass of the canoe. Since we think of our two different weight canoes as the same shape hollow cylindar, our angular momentum equation can be rewritten.

L = constant * mass * angular velocity

So this means a 30 lb canoe will have 50% higher angular momentum over a 20 lb canoe... of course that's neglecting the angular momentum of the paddler -- which in reality, I don't think is such a bad estimate since the person is close to the center. Even if it's not the greatest estimate, my conclusion is that the weight of the canoe does affect angular momentum a fair amount. How much this changes your race results is a whole different thing though... It would interesting to record data of the angle of your canoe over the course of a race.

Anyway, I don't really know what I'm talking about and could be entirely wrong, but I do think trying to understand everything is more important than the spiritual/emotional stuff. ;)


#34 Sat, 12/01/2007 - 10:51pm


Right on Keizo. I think that's what we are really looking to define, the moment of inertia, not necessarily angular momentum. (my mistake)

I think the standard formulas for rod shaped objects are a better fit.

Regardless the result stays the same. Linear correlation between mass and moment of inertia.


#35 Sat, 12/01/2007 - 11:41pm


^^ "rod shaped objects are a better fit."

Sorry, couldn't help it. I'm still in preschool.


#36 Sun, 12/02/2007 - 12:01am


Donald,

No worries. And if you are buying the beers, I'll be happy to drink them. :)

Fortunately, wikipedia has a wealth of information. As already discussed, the key piece to angular momentum is the calculation of moment of inertia. The link Keizo beat me to providing, has the integral formulas already resolved their algebraic functions for many common shapes. Which gets me off the hook since I haven't done any serious calculus since '97.


#37 Sun, 12/02/2007 - 12:44am


Here's a seat-of-the-pants quantification. You're neck and neck with a paddler between Hawaii Kai and Kaimana on a big day. The quicker manuverability of the lighter boat allows you to crank at the last second, a 20 degree turn and jump onto a wave that puts you into the lead by 20m. The boat just paid for itself, and you didn't even have to stop eating at MacDonalds.


#38 Sun, 12/02/2007 - 9:45am


said perfect


#39 Sun, 12/02/2007 - 11:31am


how does the boat pay for itself? Oh, you got 1st place at a race offering $3000 cash prize. Sweet.

Back to real world, some killer info in this thread, mahalos to you mathematicians for putting the brain power into these never ending questions.

One thing I struggle with; in flat water conditions I can feel the weight, wind, balance, drag, technique and fitness level all play a role in the hull speed. All variables that we try to perfect. And when I think I have a good enough understanding, conditions rock my confidence ....specifically upwind.

There seems to be an aditional force (other then wind) holding me back. The nose of my hurricane points up, while the stern is 90% underwater (in heavy headwind). At 6'3 187 its hard to move the seat forward, and I havent found it helpful.

Now, what if I was to add 5Lbs of weight to the nose?

Eckhart, any suggestions?


#40 Sun, 12/02/2007 - 8:00pm


^ Paid for itself = It was worth the extra money for the premium layup. But yeah, thats a valuation to be made by each individual paddler.

I disagree wih the premise of the original post.

It begins with the statement: "SOME builders are making very light boats that require you to be extra careful with the boat to keep from dinging them, or having structural issues. OTHERS are building a boat that will last many more years."

Then leads to the question: "In a sport that has no financial incentives, is having the LIGHTEST boat possible really that important? Where do we draw the line between going as fast as possible, and having QUALITY products?" (my capitalizations)

First, a heavier layup does not directly equate to quality. I look at the handful of boats from the top builders/designers in Hawaii, and I do not see lightweight coinciding with "structural issues" or a compromise in boat life. Quality and lightweight are not OPPOSING characteristics that cannot exist together in the same boat.

A light carbon boat is stiffer and more lively than a heavier non-carbon boat. The lighter boat is more responsive. It rewards good technique, knowledge of the water, and aggressive paddling. Does it require more care in transport to and from the water? Yes. Is that a problem? Not for me.


#41 Mon, 12/03/2007 - 5:19am


I noticed not many people are mentioning shape of the hull. which I think has allot to do with the design and speed. my father said look at a fish and he will teach you how to build a canoe. then all that left is the weight and workmanship. in the past short while I have tried a lot of fast canoes and think your splitting hairs when you get the fast canoes together. and how a canoe leaves the water behind it when it leaves is important. The biggest point is training.


#42 Mon, 12/03/2007 - 6:25am


Whitewater I agree with you for the most part except that some builders are pushing the weight issue to dangerous extremes. Certainly fiber orientation and less if any "breaks" in the fiber weave, or even converting to prepregs, will help reduce weight as well as add stiffness and strength, but some are asking the laminate to do more than is safe. Granted, many paddlers are extraordinary watermen/women who can handle themselves if they ever find themselves in the water without a boat, but many who buy these fraglie boats are not, and would not survive if their canoe broke/sank 5 miles off shore. I dont know if it has happened yet, but, sadly, when it doest the builder will be called upon to explain why he built a canoe/laminate that was so delicate. The question is...... Is it the builders responsibility to build in safety as well as all those other things we demand? Regardless of what we think, a grieving family, a court and jury are going to look for responsibility....and blame! Just a thought.


#43 Mon, 12/03/2007 - 8:12am


Whitewater, your point is correct. A lighter boat doesn't necessarily mean a more fragile boat. But from my experiences it often does. I have been around many surfskis and found that the lighter boats never last as long. IE: I have seen Roseskis last 20 years. While 20 lb hydroskis have lasted only 2 years.

Craftmanship is a major factor here too. I have seen 40 lb twogood makos fall apart in a year.

So I guess it all just depends. What I just noticed was I just contradicted all my own points in this message. Poopie you are an idiot, you berating inconsiderate GOON.

poops


#44 Mon, 12/03/2007 - 8:51am


poopoopaddler, you make some important points. I had tried to mention the increased importance for lightweight boats, of design engineering and quality construction in my earlier post, but got lazy and ended up deleting it. Maybe I might be out of reference for this discussion, but an example of what I mean by lightweight would be an imported Peg, as opposed to say a Hyper or a glass Naia (no judgement calls, just examples).

In reference to surf-skis, what vintage were those 20# hydroskis? As far as I know, the nomex honeycomb core kevlar-skinned heat-cured epoxy Epic skis have been doing very well at 23-25#, which is considered lightweight for skis. The carbon Fenns are in the same weight range.

I don't doubt that some OC-1s are being special built to weight specs that might limit their effective life, and make them unforgiving of less experienced paddlers in big conditions. For some reason I thought of such boats to occupy a category beyond lightweight. Ultra-lightweight, if you will. I guess shut up now.


#45 Mon, 12/03/2007 - 10:02am


keizo... kd, thanks for the additional thought on the subject. yeah, i'm reviewing some old physics here too and not beyond a mistake...

yes... what i described in my last post is moment of inertia, a property of the object. i ignored angular velocity (the same for both logs) which would have described a specific angular momentum, ie. the equation for angular momentum reduces to that for moment of inertia:

the summation of mass times radius squared across the entire length of the log, boat, etc... radius (length) is still a geometric factor and mass a linear factor.

anyway, sorry, i'm loosing track of which axis we're talking about but can think of three:

(1) latitudinally with the boat/paddler in the center, for which i contend moment of inertia isn't so greatly affected for a modest change in mass (carbon fiber vs. fiberglass) and most certainly is affected by boat length and is what i think keizo described (bow and stern at great r from center where the paddler sits) in his last post
(2) longitudinally, where the ama factors in
(3) turning, say with the boat coming off the bottom of a wave where it's a point on the circumference of an arc whose center is somewhere in the air overhead or over a crest where the center is somewhere deep underwater

as for (1), no the canoe is definitely not a hollow body along this axis, there is mass along its entire length connecting the bow to the center to the stern... the equation cannot be thought of without integration (in calculus sense) and the 50% greater moment of inertia for the 30lbs boat a very large overestimate. true, the canoe is a hollow body along the longitudinal axis.

as for (2), i'm easily convinced about the importance of moment of inertia here. this can be affected by mass, true, but more strongly by radius (iako length). as for design, i wish modern oc-1 allowed more flexibility in rigging the ama (for instance +/- 10cm) the way some of the older, ostensibly clunkier designs did or some kludged together homemade designs do. this would help fit a boat to different size/shaped/skilled paddlers as well as conditions (the glassy lake in alberta or your hawai'i kai run with a full on south swell).

as for (3) here it's unclear to me whether high moment of inertia is a help or a hinderance because the water isn't solid, ie., the boat can sink into it. high moment of inertia and sinking boat would seem bad because the boat will slow from drag. high moment of inertia and planing boat (ocean surface more like solid surface) would seem good because of maintenance of velocity (certainly not angular because the boat doesn't fly up into the air). either way, in this scenario it's boat + paddler mass.

i'm not trying to argue boat weight has zero influence... just to not overestimate it given a wide variety of factors involved. hull stiffness, is a whole additional story... in surfing as you probably are also aware, there's a good debate going on over stiffer vs. springier boards (stringer type and thickness, epoxy vs. polyester and so on).

sure... spiritual appeal is important too and fish good models, but choose the right fish. sharks excel at going round and round.

btw, poopoo: i'm almost over my flu and its concomittant mental illness and soon will be blissfully away from a computer and temptations to post on any forums.


#46 Mon, 12/03/2007 - 1:02pm


a boat is not fiberglass or carbon fiber but rather some cloth + resin. why are really nice carbon fiber boats not always built with epoxy, which is both stronger and safer to both builder and consumer? because epoxy is about 2x cost of polyester resin?

to anyone who would like to debate the toxicological safety issue, i'm open to discussion but also prepared to throw a whole lot of 300 page pdfs from national institute of health and center for disease control your way. the evidence for neurological damage from styrene monomers that make up about 40% of a can of polyester resin pretty indisputable (and i'm talking studies on boat builders not lab rats) at this point and the evidence that the same monomers at least mild carcinogens in humans mounting... sailboat builders tell me polyester resin hulls for liveaboard boats are discouraged as too dangerous where people sleep in a closed environment.

given strength and safety, given current state of knowledge, i'll definitely pay more for epoxy before worrying about paying more for carbon fiber.

also, just where is the weight savings coming from in a carbon fiber boat? last i checked a yard of 6oz carbon fiber weighed the same as a yard of 6oz fiberglass. i presume the carbon fiber boats are built with lighter fabric, for instance 4oz instead of 6oz? or is there some other trick to saving weight with carbon fiber? (i've only used it in bike parts and paddles).

independent of what resin is used, given two identically layed up boats of equal weight... isn't the carbon fiber boat stronger? the weakness comes from using lighter fabric to save weight, no?


#47 Mon, 12/03/2007 - 1:34pm


Gooeyduck, I always enjoy reading your threads cause I always make a cameo appearance at the end!! One question for you: isn't epoxy susceptible to UV degradation and resin not? Or am I wrong on that one. Just another thought why someone would want resin.

Whitewater, the hydros were 1st and 2nd generation. Both gens had issues with gelcoat and delam.

The epics that I have been around also have had some issues. Leaks, and soft spots. It seemed like they were sucking up water and turning into mush. Epic has super awesome customer service and had them repaired at no cost. But recently there have been some new soft spots.

I just haven't had good luck with kayaks. They just aren't built to last like the Roseskis were. Twogoods being the worst and the worst customer service.

Holy crap I'll never write this much ever again

Poop on ME


#48 Mon, 12/03/2007 - 1:45pm


I'm curious as to exactly which hydroski's we are talking about my experience has been that Robello built the best boat around. I had a 24 lbs 3rd generation that was the stiffest boat i have ever saw.I beat the piss out of it, and it was still stiff as hell. The gelcoat on early hydroskis did peal but that was mainly because Billy was one of the first to utilize vacuum bagging, and therefore one of the first to deal with the epoxy polyester bond, which was solved in previous generations. Any ways you can always tell which boat is which by looking in the back drain plug. Robello would write the name of the boat owner in the inside the hull. Also it should be noted that Marshal Rosa is road a hydroski for many years after the production of the Roski stoped.


#49 Mon, 12/03/2007 - 11:11pm


uv damage: definitely something to consider with epoxy. typical solutions include pigment, polyester resin gloss coats (very much less than ideal since, as i think waterboy alludes to, it doesn't adhere well to the epoxy underneath it and, well, then you need polyester resin around; nevertheless, lots of epoxy surfboards hit the showroom floors like this). i personally like the solution of coating with polyurethane varnish after sanding... but mostly just limit myself to paddling at night-- easy when the sun seems to set right after lunch. not storing boat/surfboard/paddles in the sun goes a long way.

some folks don't like epoxy for finishing layers since it's somewhat more prone to tiny pits... there are tricks to dealing with these, probably more than i know... two that i like are leaving my pot of epoxy in an evacuated belljar for 10-15 minutes prior to coating, which subsequently really makes one work efficiently... and again, the polyurethane/spar varnish layer over. since my junk doesn't do showroom, it really has less need for high gloss finish anyway.

i'm still curious... where is this weight savings in most carbon fiber boats coming from... using lighter glass (4oz vs 6oz)? lighter, less absorbent mats and subsequently less resin filling in the matrice?


#50 Wed, 12/05/2007 - 5:18am


maybe this is a plug, but certainly not one i profit from:

http://www.hesssurfboards.com/

i haven't ridden one but i have seen them and they're a-f'n amazing... very light given that they're wood. granted, not nearly as light as a polyurethane foam sliver with a single layer of 4oz glass on it. it could be interesting to adapt to boats; something of a combination of the well known techniques of a composite with mats and a plywood stitch construction.

prices do start around $1200. ouch.


#51 Wed, 12/05/2007 - 5:28am


Skimming over most of this thread, I think everyone needs to consider the relevance of the small (or even tiny) improvements and the cost/hassles of ultralight equipment.

If you race, are doing everything in your power to be fit, light, focused, motivated, and you are still losing by small margins, then get the lightest/fastest rig you can.

If you are losing by big margins, racing mid-pack, or not racing at all then perhaps its time to prioritize your needs vs wants. We all want the best boat possible but can we afford it and can we afford to potentially replace/repair it in a year or two?

My advice: train smarter and harder, eat less, save your money for your kid's college fund.

Raphael


#52 Wed, 12/05/2007 - 6:45am


Raphael, you mean to tell me that the reason I am in the back of the middle pack is not because my boat weighs 2 lbs more that the people in the front? I think you are wrong, if I had the super light boats like the champs, I would be one too.


#53 Wed, 12/05/2007 - 7:44am


Poops,
Maybe you should have some fundraisers so you can afford that new ultra-light boat.
I hold a fundraiser for myself just about every day - it's called "going to work".


#54 Wed, 12/05/2007 - 9:39am


on a bad day I near the back and on a good day near the front.I cant afford the canoe. and the $ for a canoe makes no cents at all. Its not the lightest on but its the do it all canoe. and when I am walking away from it i still look back at it. and smile.I should be a comercial.


#55 Wed, 12/05/2007 - 2:25pm


I think you should shoot for President. THis country needs you.


#56 Wed, 12/05/2007 - 3:01pm


poopoo I know a cheap way to make your boat lighter. Remove some material, drill holes on the deck, above the waterline and on the iakos. you can save at least 4lbs. Paddle naked, you'l save the weight of your clothes, around 1lbs. Do not carry anything to drink, 3lbs less. You can even shave your head, from 0.1 to 2lbs depending on your actual hairstyle.
Good luck, now you're gonna beat the champs !


#57 Wed, 12/05/2007 - 3:04pm


Mulus, you absolutely break me up ... you're a breath of fresh air on this Forum. ... i think you got Poo poo bamboozled ... Hahaaaa.

Cheers Rambo


#58 Wed, 12/05/2007 - 3:18pm


I am not sure where this string is going anymore, I started it and I have lost track and can't think of what, how or if I should say anything, When Keizo and Gduck start talking in geek math code I am out.
However I do know that painteur's computer just got flagged by some secret government agency.


#59 Wed, 12/05/2007 - 4:50pm


why is it that everytime a thread begins to talk about canoe weight or even differences between canoes that ten people will go on a rant about it being the paddler and not the canoe that makes a difference. And that before people buy a light canoe they should think about losing weight first... Obviously speed is primarily from the paddler, nobody is saying otherwise, but everyone has the right (god given right i believe) to try and get the best equipment available. There is no reason to be stuck on a heavy canoe because you are overweight. If you are a bad tennis player should you use a heavy racket? Alright, sorry for going on a rant myself... Its late and im pretty bummed on studying right now.


#60 Thu, 12/06/2007 - 12:40am


ha, i was a little quick to criticize. After reading back through the thread a lot of good stuff was said with very little "naysaying." anyways, this is the most interesting thread about canoes since those last threads about... Foreign made canoes. And again, sorry for my little rant above, I had not fully read through the thread. And I'm just sour because I'm one of those people with really good equipment who doesn't spend enough time on the water. Except in by case I tend to lose weight when Im not paddling. Which, according to this thread, may be a good thing.
I should probably put an opinion too so I can redeem some value from my posts. I never gave boat stiffnes a thought until recently, but after going back and forth between some very stiff canoes and some with normal lay ups I have decided for myself that I really really think the stiffnes makes a big difference in the surf, a bigger difference than a few pounds if weight will make. However, I also think weight is crucial no matter how many theorems may disprove it. So, go for light, but go for stiffness first (in my opinion).


#61 Thu, 12/06/2007 - 1:08am


HA! I bet you guys thought I was going to invent some unappreciated joke regarding stiffness and make sexual connotations or guileful remarks about penile preferences. Shame on you all!

But stiffness is no laughing matter! Luke I had a previous post on boat stiffness. I am interested in hearing more about the difference the stiffness made. I have had discussions with people that adamantly believe that super stiff 6-man canoes is the difference between winning and losing.

What exactly did you notice about the stiffer boat? What was the differences in the layups? What about flat water?

Poops


#62 Thu, 12/06/2007 - 3:07pm


^^yeah luke, what she said....


#63 Thu, 12/06/2007 - 6:30pm


This is a pretty lame answer, but i truly canʻt describe how the stiffer canoe feels better. There were a couple of things different about the foam core canoe that i tried (new rudder, slightly different rig), and it could have been any of them. But the stiff canoe truly felt like the best canoe iʻd ever been in in the surf. I canʻt say anything specific about it... other than that i just felt.... solid in it. When i picture myself on the canoe i feel like it reacted to every bit of energy in the ocean, rather than absorbing it like a less stiff canoe. But i donʻt know if thatʻs truly what it does. It just feels good.
In the flat i donʻt think it really matters, or at least i couldnʻt really tell a difference... but everything in the flat always feels the same to me, so iʻm not the best judge on that.


#64 Thu, 12/06/2007 - 10:27pm


given all the talk about super light boats coming out of china, or wherever else for that matter, i found this thread interesting nearly six years after the fact.

and yup, I'm still in preschool.


#65 Fri, 05/03/2013 - 9:59pm


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