Advantages of backbone?

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robbyw
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Advantages of backbone?

Post by robbyw » Sat Mar 21, 2009 6:36 am

Having heard many people argue one side or the other about the effects of backbones on performance, I would like to hear what are the ways this happens:

Does it precent excesive longitudinal flexing?

Does it cause the floor to becaume taughter and thus offer less resistance to advancement?

Does it prevent one's behind from deforming the flattness of bottom and so increasing drag?

Does it create a V keel shape that improves tracking?

lee johnson
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Joined: Tue Dec 02, 2008 2:51 pm
Location: vancouver canada

Post by lee johnson » Tue Mar 24, 2009 5:31 am

Robby -

The answer to each of the questions you raise is a resounding "Yes." Although AE Advanced Frame kayaks are designed to work very well when properly inflated, adding a BackBone adds another dimension to their performance. The main thing a BackBone does, so far as my son and I are concerned, with our AF 1s and Expeditions, is to impart a "V" shape to the hull. When you sit inside your kayak, your weight presses down on the BackBone and turns it into a keel that gives the hull a gull-winged V. The V comes from your weight; the gull wing comes from water pushing back on hull from the BackBone up to the waterline. The result is much better tracking and gliding. Also, longitudinal rigidity is ensured so that, if you are crashing into large waves, your craft will not "taco" in the middle. Other IK manufacturers are trying to find equivalents to the patented system of AE's aluminum forms + BackBone to achieve this rigidity and gull-winged V-shaped hull; so, if you have any further doubts about the role a BackBone plays in the clever Advanced Frame system, look at who is being imitated!

robbyw
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Joined: Sat Mar 21, 2009 6:27 am

Backbone

Post by robbyw » Sat Mar 28, 2009 4:57 am

Lee:

Thanks for the reply!. Just curious, how did you observe this? Did you look at the bottom underwater while someone was on the canoe?

Also, I would like to know if adding the BB affects comfort? ie can you feel the BB under your behind as if you were riding a bicycle on the top tube?

For your info, I have a AE Conv

lee johnson wrote:Robby -

The answer to each of the questions you raise is a resounding "Yes." Although AE Advanced Frame kayaks are designed to work very well when properly inflated, adding a BackBone adds another dimension to their performance. The main thing a BackBone does, so far as my son and I are concerned, with our AF 1s and Expeditions, is to impart a "V" shape to the hull. When you sit inside your kayak, your weight presses down on the BackBone and turns it into a keel that gives the hull a gull-winged V. The V comes from your weight; the gull wing comes from water pushing back on hull from the BackBone up to the waterline. The result is much better tracking and gliding. Also, longitudinal rigidity is ensured so that, if you are crashing into large waves, your craft will not "taco" in the middle. Other IK manufacturers are trying to find equivalents to the patented system of AE's aluminum forms + BackBone to achieve this rigidity and gull-winged V-shaped hull; so, if you have any further doubts about the role a BackBone plays in the clever Advanced Frame system, look at who is being imitated!

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Daddy-O
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Location: Dominican Republic

Post by Daddy-O » Sat Mar 28, 2009 8:36 am

Robby,
I have not looked under our Convertibles yet while we are in them to see the v-shape mentioned, but you can see it when the Convertible is empty. It is the lowest part of the kayak and will receive the greatest amount of pressure from the people sitting on top. I am sure that it will be pressed down, and the v-shape will be more pronounced as a result.

As far as comfort, I can comment on that. We went on a long paddle last week with them. I started out with an extra cushion under my seat (between the inflatable floor and my seat). Later, I removed that cushion to see how I liked it. I forgot about the cushion and went the rest of the trip without it. I didn't notice any discomfort as a result. Some people say that it bothers them. Maybe I just have more natural padding than others. :roll:

Daddy-O

lee johnson
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Joined: Tue Dec 02, 2008 2:51 pm
Location: vancouver canada

Post by lee johnson » Sat Mar 28, 2009 11:25 am

Robby -

Perhaps our Site Admin, JCooley, will weigh in to verify and refine the effects BackBones have on IKs; but, for now, let me make a few suggestions:

1) By Yourself: Inflate your kayak without BackBone and lift up one end. The hull will be rather flat, rounding slightly until it finally goes up at the sides. Then, install the BackBone and lift up the same end. Now, the hull will have a V shape; and you may even start to see the concave beginnings of a gull-wing contour from the BackBone to the sides - a concave contour that is much deeper when water pressure is against it. People often come up to me as I am getting my AF1 or Expedition ready for a session on the water, and in a couple of cases, I have lifted up the craft to show how the BackBone works. The people who saw this were owners of hardshells who were convinced that the Advanced Frame system really makes sense, especially after seeing my son or myself demonstrate, on the water, how fast these kayaks go and how well they track and glide. In both cases, these people said they were going to purchase AE kayaks with BackBones (because they were tired of lifting and transporting their hardshells, which can be a problem when one is alone).

2) With Help: Dive under water and look at the hull of your companion's kayak - at least feel it, under weight and against water pressure. I now have a compact and clever Pentax W 60 underwater digital camera, and I may be able to send you photos of the gull-winged V shape when I get my exposure times figured out. At the very least, I should be able to send you photos of the hull as it looks when lifted up on land (see "1" above).

3) As a "Thought Problem": Go to Bicsports and look at their new "future of inflatable kayaks" - their new Yakkair line, which is obviously a tribute to AE's designs. They use a hollow inflatable keel and a high-pressure floor to achieve their V and gull-winged shapes. But their keel is comparatively and necessarily flexible, in relation to AE's BackBone, and the beam width of their IKs is greater, and therefore less desirable, than AE's. Also, I would think their high-pressure floor would be less comfortable than AE's low-pressure "air mattress" floor, which is very comfortable while keeping the BackBone from being noticeable. The reason Bicsports, which makes excellent kayaks, has to resort to their less rigid system is that AE has patents and patents pending on all their superior Advanced Frame designs.

Let's face it, IKs, compared to rigid kayaks, are less efficient because they flex, absorb and waste energy - but AE has a solution to this problem: the rigid aluminum frames + BackBone give an internal architecture that makes the Advanced Frames high-performance alternatives to, at least, wide-beamed hardshells. On the Lagoon 1 and Firefly, though, such a system is not necessary because of the short length of the crafts. The longer the craft, the more useful (in my view) the BackBone to provide hull-rigidity. You say you have an AF Convertible - well, try the BackBone and let us know how it compares to a well-inflated but spineless kayak!

robbyw
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Joined: Sat Mar 21, 2009 6:27 am

Post by robbyw » Sat Mar 28, 2009 6:44 pm

Hi Lee, Daddy O

Thanks for your comments. When buying my boat last Dec I did not get the BB. I did so based on the suggestion of AE staff to first try the boat as is as well as some comments from people who could not tell much difference.

After using it for a couple dozen outings and comparing to my experiences while canoeing or kayaking with rigids, I noticed a significantly lower speed as well as quick deceleration when I stopped paddling. I am overseas but may be able to buy a BB on my next trip.

Unfortunately, I cannot do the tests you mentioned so I wanted to get some evidence as to the workings of the BB to avoid spending money on a potential "gimmick" as well as adding weight and volume to the boat or the packed boat in the carry bag.

BTW, I did look at the BIC online and by the specs, photos seems a great boat though at a higher price.. It is 30% lighter than equivalent AEs. has high pressure (6.5psi) inflatable keel and floor (water collects below floor), has leg straps, all around grab line, backpack, pump w/ gauge. Have not seen them in real life, read reviews though.

I look forward to seeing pics of the AE bottoms with BB, thanks for the offer


lee johnson wrote:Robby -

Perhaps our Site Admin, JCooley, will weigh in to verify and refine the effects BackBones have on IKs; but, for now, let me make a few suggestions:

1) By Yourself: Inflate your kayak without BackBone and lift up one end. The hull will be rather flat, rounding slightly until it finally goes up at the sides. Then, install the BackBone and lift up the same end. Now, the hull will have a V shape; and you may even start to see the concave beginnings of a gull-wing contour from the BackBone to the sides - a concave contour that is much deeper when water pressure is against it. People often come up to me as I am getting my AF1 or Expedition ready for a session on the water, and in a couple of cases, I have lifted up the craft to show how the BackBone works. The people who saw this were owners of hardshells who were convinced that the Advanced Frame system really makes sense, especially after seeing my son or myself demonstrate, on the water, how fast these kayaks go and how well they track and glide. In both cases, these people said they were going to purchase AE kayaks with BackBones (because they were tired of lifting and transporting their hardshells, which can be a problem when one is alone).

2) With Help: Dive under water and look at the hull of your companion's kayak - at least feel it, under weight and against water pressure. I now have a compact and clever Pentax W 60 underwater digital camera, and I may be able to send you photos of the gull-winged V shape when I get my exposure times figured out. At the very least, I should be able to send you photos of the hull as it looks when lifted up on land (see "1" above).

3) As a "Thought Problem": Go to Bicsports and look at their new "future of inflatable kayaks" - their new Yakkair line, which is obviously a tribute to AE's designs. They use a hollow inflatable keel and a high-pressure floor to achieve their V and gull-winged shapes. But their keel is comparatively and necessarily flexible, in relation to AE's BackBone, and the beam width of their IKs is greater, and therefore less desirable, than AE's. Also, I would think their high-pressure floor would be less comfortable than AE's low-pressure "air mattress" floor, which is very comfortable while keeping the BackBone from being noticeable. The reason Bicsports, which makes excellent kayaks, has to resort to their less rigid system is that AE has patents and patents pending on all their superior Advanced Frame designs.

Let's face it, IKs, compared to rigid kayaks, are less efficient because they flex, absorb and waste energy - but AE has a solution to this problem: the rigid aluminum frames + BackBone give an internal architecture that makes the Advanced Frames high-performance alternatives to, at least, wide-beamed hardshells. On the Lagoon 1 and Firefly, though, such a system is not necessary because of the short length of the crafts. The longer the craft, the more useful (in my view) the BackBone to provide hull-rigidity. You say you have an AF Convertible - well, try the BackBone and let us know how it compares to a well-inflated but spineless kayak!

lee johnson
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Joined: Tue Dec 02, 2008 2:51 pm
Location: vancouver canada

Post by lee johnson » Sun Mar 29, 2009 3:59 pm

Robby W - I've put a temporary photo of my EXP with BackBone on the AE "About Us: Photo Gallery" site. The photo shows the BackBone and the shaping of the hull, even as the kayak sits sideways, without any weight on the BackBone to bring it to its full value. Even though cameras tend to flatten 3-D into 2-D, you can see, via the shadows, the shaping of the hull. I then took my Expedition out on the salt water on a day with 25-30 knot winds, whitecap waves, and two-to-three foot swells. I crashed into some pretty impressive waves, but the Expedition was absolutely solid, thanks in part to the BackBone. I could track effectively, without "weathercocking" or other problems. The main thing you will notice, I think, about adding a BackBone is the gliding you will get - the kayak just keeps on going. Without the BackBone, it slows immediately. On a wild day on salt water, as I just experienced, I was glad to have a craft that could handle rough conditions with such aplomb. When you have seen the photo, let me know, and I'll delete it - it's not much to look at, aesthetically!

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Daddy-O
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Post by Daddy-O » Sun Mar 29, 2009 5:18 pm

Hey Lee,
I think you should leave that photo up. It is a side of the kayaks that hasn't been shown and could be helpful to some people curious about the backbone. Well, that's just my opinion, though. :wink:
Daddy-O

robbyw
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Joined: Sat Mar 21, 2009 6:27 am

Post by robbyw » Sun Mar 29, 2009 5:42 pm

Lee:

Thanks for the picture!. I think you've convinced me to get a BB as per the performance argument. The only thing that I worry is that being 225 lbs, I might feel it under me as some reviews on amazon warn.

best,

R



lee johnson wrote:Robby W - I've put a temporary photo of my EXP with BackBone on the AE "About Us: Photo Gallery" site. The photo shows the BackBone and the shaping of the hull, even as the kayak sits sideways, without any weight on the BackBone to bring it to its full value. Even though cameras tend to flatten 3-D into 2-D, you can see, via the shadows, the shaping of the hull. I then took my Expedition out on the salt water on a day with 25-30 knot winds, whitecap waves, and two-to-three foot swells. I crashed into some pretty impressive waves, but the Expedition was absolutely solid, thanks in part to the BackBone. I could track effectively, without "weathercocking" or other problems. The main thing you will notice, I think, about adding a BackBone is the gliding you will get - the kayak just keeps on going. Without the BackBone, it slows immediately. On a wild day on salt water, as I just experienced, I was glad to have a craft that could handle rough conditions with such aplomb. When you have seen the photo, let me know, and I'll delete it - it's not much to look at, aesthetically!

Pearly
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Post by Pearly » Mon Mar 30, 2009 12:06 am

Daddy-O wrote:Hey Lee,
I think you should leave that photo up. It is a side of the kayaks that hasn't been shown and could be helpful to some people curious about the backbone. Well, that's just my opinion, though. :wink:
Daddy-O
I agree!

robbyw
Posts: 23
Joined: Sat Mar 21, 2009 6:27 am

Post by robbyw » Mon Mar 30, 2009 5:56 am

For reference, I re-post what the site administrator said about the BB a year ago (I got the same answer when I called 3 months ago)


As long as the kayak is inflated properly, you really don't need the backbone. It will increase the tracking a performance a little which is more noticable in the longer kayaks. It is a nice enhancement to the kayak. It creates more of a V shaped hull which increases overall performance. Start out by trying the kayak without one. You will more than likley notice that the kayak performs great without one. If you think that you need a little extra omph at a later point, get the backobone. Maybe try to find a used one or one on sale.

Jeremy

lee johnson
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From Photo Gallery

Post by lee johnson » Mon Mar 30, 2009 10:47 am

Last edited by lee johnson on Sat Sep 19, 2009 8:41 pm, edited 3 times in total.

lee johnson
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To "B" or Not To "B"

Post by lee johnson » Wed Jul 01, 2009 7:06 am

An AE kayak works just fine
Without a BackBone for a spine;
But, with a BackBone, you should be
Able to face large waves at sea;
So, if your craft is "taco-chipping"
And brings you to the brink of tipping,
Using a BackBone for your keel
Should give your craft a safer "feel" -
But, on calm waters, you'll be fine
Without a BackBone for a spine.

(Happy Canada Day!)

lee johnson
Posts: 104
Joined: Tue Dec 02, 2008 2:51 pm
Location: vancouver canada

Postscript to the Foregoing Verse

Post by lee johnson » Wed Aug 12, 2009 11:26 am

Postscript to the Foregoing Verse
(Or, Ode to a BackBone)

And yet . . . and yet . . .we must admit
This item helps more than a bit:
Without it, life is far from tragic,
But having one is just like magic --
All of a sudden, we can glide
And effortlessly enjoy our ride;
Our hulls are shaped into a "Vee" --
Victorious efficiency --
Of this device, we are most fond:
A BackBone is a magic wand.



:oops: :oops: :oops:

robbyw
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Re: Postscript to the Foregoing Verse

Post by robbyw » Sun Sep 13, 2009 8:30 pm

Sorry for the late response but you really deserve a "bravo"!


And yet . . . and yet . . .we must admit
This item helps more than a bit:
Without it, life is far from tragic,
But having one is just like magic --
All of a sudden, we can glide
And effortlessly enjoy our ride;
Our hulls are shaped into a "Vee" --
Victorious efficiency --
Of this device, we are most fond:
A BackBone is a magic wand.



:oops: :oops: :oops:[/quote]

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