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Aka Knuckles/Pins: Wear/Failure ?
http://www.hobie.com/au/en/forums/viewtopic.php?f=71&t=58900		 Page 1 of 2
Author:  PeteCress [ Tue Aug 23, 2016 7:41 am ]
Post subject:  Aka Knuckles/Pins: Wear/Failure ?
These guys: https://photos.google.com/share/AF1QipP ... JaRW5TYzBR

They seem pretty sloppy to me after about a season's use..... or are they that way out of the box?

Either way, do they fail?

If so, what fails and what sb pre-emptively replaced... and when?
Author:  warburto [ Wed Sep 21, 2016 11:45 am ]
Post subject:  Re: Aka Knuckles/Pins: Wear/Failure ?
I'm also curious about this. I've got a 2015 AI with the same issue.

I just dropped my aka bars off at the dealer for the re-glue fix and pointed out what I thought was excessive wear in the knuckles around the SS pins.

The dealer stated that the knuckles always seem sloppy on boats with more than one season on them and said he didn't think it was a big deal. I don't like the play in the knuckles myself. The combination of the loose sleeve, loose knuckles, and slop in the male/female joint to the aka brace adds up to a lot of angle when the boat has some weather on it. If my dealer doesn't address it I'll be calling Hobie directly to talk to them about it. If I can't get it resolved with Hobie, I may try a local machinist to see if they can bush the knuckles.
Author:  mmiller [ Wed Sep 21, 2016 1:45 pm ]
Post subject:  Re: Aka Knuckles/Pins: Wear/Failure ?
First... a 2015 should not need the glue fix. That was for much older boats unless it popped up once again.

The crossbar connections are designed to be a bit flexy, so movement is expected. Can you actually pinpoint the movement at the pin? Most movement is at the aka to crossbar insertion point.
Author:  PeteCress [ Thu Sep 22, 2016 6:08 am ]
Post subject:  Re: Aka Knuckles/Pins: Wear/Failure ?
mmiller wrote:
The crossbar connections are designed to be a bit flexy...
In my case, I would replace "Flexy" with "Sloppy"... as in space between two parts allowing the movement instead of bending of one part.

Look at the photo in the OP and you will see a crescent of slop that goes halfway around the pin. .... That is where the aka/ama movement is coming from: https://photos.google.com/share/AF1QipP ... JaRW5TYzBR

On mine, the other three are also sloppy, but not as sloppy as one shown - which is on the aft/left and, now that I think about it, probably explains why the ama on that side hangs down so far that it rubs on the 30cm beach wheels and I need to put a horizontal support spar across the rear deck when transporting on beach wheels: https://photos.google.com/share/AF1QipP ... JaRW5TYzBR ..... That condition has been pretty much from Day-1.

I can live with the movement.... but not with eventual failure under sail - hence the question in the OP.

I like the bushing approach - althouigh I would think that electrolytic issues may lurk beneath the choice of bushing material.
Author:  mmiller [ Thu Sep 22, 2016 8:52 am ]
Post subject:  Re: Aka Knuckles/Pins: Wear/Failure ?
That pin / area` has not been known to fail unless the set screw comes out.

What we have seen is the aka insert releasing from the crossbar if the latch gets distorted. That can allow the aka to release and back out... and that can cause cracks in the ends of the crossbar. Or worse if it comes clear out, you can. You can do any number of things to prevent the aka release issue from happening starting with regular inspection of the lock to ropes and other hardening systems talked about in the forums.
Author:  PeteCress [ Thu Sep 22, 2016 9:26 am ]
Post subject:  Re: Aka Knuckles/Pins: Wear/Failure ?
mmiller wrote:
That pin / area` has not been known to fail unless the set screw comes out.

What we have seen is the aka insert releasing from the crossbar if the latch gets distorted. That can allow the aka to release and back out... and that can cause cracks in the ends of the crossbar. Or worse if it comes clear out, you can. You can do any number of things to prevent the aka release issue from happening starting with regular inspection of the lock to ropes and other hardening systems talked about in the forums.
Sounds like "Case Closed" from my perspective.

Funny how that one is worn so much more than the others.... maybe some grit in that one....
Author:  warburto [ Thu Sep 22, 2016 9:38 am ]
Post subject:  Re: Aka Knuckles/Pins: Wear/Failure ?
mmiller wrote:
First... a 2015 should not need the glue fix. That was for much older boats unless it popped up once again.

The crossbar connections are designed to be a bit flexy, so movement is expected. Can you actually pinpoint the movement at the pin? Most movement is at the aka to crossbar insertion point.


Hi Matt, thanks for the reply. 2015's not needing the glue fix was what the dealer told me that you guys (Hobie) told him as well. Nevertheless, the rivets on all four bars are loose and no glue is evident.

Regarding the movement at the pins; yes I can pinpoint the movement at the pin. The holes in the outer knuckles are egged, allowing the pin to slop back and forth along the main axis. The dealer stated that he would take a video of the play and forward it to Hobie for review. I look forward to hearing the response.
Author:  mmiller [ Thu Sep 22, 2016 10:10 am ]
Post subject:  Re: Aka Knuckles/Pins: Wear/Failure ?
Warranty forwarded that to me just now. That is very loose and something I will have to look into.
Author:  PeteCress [ Thu Sep 22, 2016 10:37 am ]
Post subject:  Re: Aka Knuckles/Pins: Wear/Failure ?
warburto wrote:
The holes in the outer knuckles are egged, allowing the pin to slop back and forth along the main axis.
Much more so than in my photo, right?

(https://photos.google.com/share/AF1QipP ... JaRW5TYzBR)
Author:  mmiller [ Thu Sep 22, 2016 11:20 am ]
Post subject:  Re: Aka Knuckles/Pins: Wear/Failure ?
We will have the loose set of akas here at Hobie Cat this afternoon. Fast Lane is bringing them up.

That is not the way these should be and something has changed in my mind, but we have to get engineering involved and figure it out.
Author:  warburto [ Thu Sep 22, 2016 12:02 pm ]
Post subject:  Re: Aka Knuckles/Pins: Wear/Failure ?
PeteCress wrote:
warburto wrote:
The holes in the outer knuckles are egged, allowing the pin to slop back and forth along the main axis.
Much more so than in my photo, right?

(https://photos.google.com/share/AF1QipP ... JaRW5TYzBR)


Sorry for thread-jacking you Pete.

Yeah, all four of my aka knuckles showed more gap than the one you have pictured, and one of them had egged the hole, leaving space on both sides.
Author:  mmiller [ Thu Sep 22, 2016 2:05 pm ]
Post subject:  Re: Aka Knuckles/Pins: Wear/Failure ?
We got to see these parts first hand.

The movement is out of spec, but far less in reality than what the video seems to show. This amounts to fractions of an inch at the ama ends. Even new boats have some movement. Could possibly be tighter, but is a used boat. For sure the casting should have had glue. Fast Lane will be back in contact.

This does nothing to change the function as the boats all vary a bit and there are many places in the connections that stack up to create movement at the amas. This is not a failure concern.
Author:  warburto [ Thu Sep 22, 2016 2:21 pm ]
Post subject:  Re: Aka Knuckles/Pins: Wear/Failure ?
mmiller wrote:
We got to see these parts first hand.

The movement is out of spec, but far less in reality than what the video seems to show. This amounts to fractions of an inch at the ama ends. Even new boats have some movement. Could possibly be tighter, but is a used boat. For sure the casting should have had glue. Fast Lane will be back in contact.

This does nothing to change the function as the boats all vary a bit and there are many places in the connections that stack up to create movement at the amas. This is not a failure concern.


Having used the boat, I'd beg to differ on the amount of play seen at the ama, it adds up to more than fractions. The aka bars droop enough when portaging the boat that they drag on the ground. I have to tie them up when wheeling the boat, and even then they rub the tires. As you say, doesn't change the function of the boat on the water, it seems to sail fine, if a bit tilted when under sail.

Thanks for your response and time looking at the bars.
Author:  PeteCress [ Thu Sep 22, 2016 2:34 pm ]
Post subject:  Re: Aka Knuckles/Pins: Wear/Failure ?
warburto wrote:
... The aka bars droop enough when portaging the boat that they drag on the ground. I have to tie them up when wheeling the boat, and even then they rub the tires. ....
Here's my workaround for that: https://photos.google.com/share/AF1QipP ... JaRW5TYzBR

When sailing, I clip it to the paddle stash on the port side.... nice to have a walking stick and/or emergency spar, or I'd just leave it on the beach.

I'm also going to try it out for recovery from full turtle: stick the narrow part into a scupper hole and pull on the end of the long part to rotate the hull enough so that I get sufficient leverage from the righting line. ..... Dunno how much rotation is needed, but hopefully it is only 10-15 degrees..... and hopefully all that leverage won't damage the scupper channel.
Author:  mmiller [ Thu Sep 22, 2016 2:47 pm ]
Post subject:  Re: Aka Knuckles/Pins: Wear/Failure ?
warburto wrote:
Having used the boat, I'd beg to differ on the amount of play seen at the ama, it adds up to more than fractions. The aka bars droop enough when portaging the boat that they drag on the ground. I have to tie them up when wheeling the boat, and even then they rub the tires. As you say, doesn't change the function of the boat on the water, it seems to sail fine, if a bit tilted when under sail.


Yes, when folded... I am talking about sailing configuration. When folded in... that is an entirely different thing. Yes, they droop. This is expected and is normal.
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