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PostPosted: Thu May 03, 2012 4:48 pm 
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Location: Delaware Coast
I share sEs's concern.

Originally, all the weight of your boat was being carried by the tongue resting on the suspension box. As you have modified it, all the weight is now being hung from 4 T-Bolts. I read somewhere that some people have had problems with the T-Bolts fatiguing the area in the channel that they fasten into causing cracking. With sEs's suggestion of two more brackets, you would have the weight carried by 8 bolts.

sun E sailor wrote:
In the pictures the length of your box frame looks short. Was this changed for some reason or is this the way it's supposed to be?
The picture of yours certainly doesn't match the picture in the Assembly Sheet on Trailex's site.


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PostPosted: Tue May 08, 2012 11:33 am 
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Location: Puget Sound, Washington USA
Jeff, sEs, Bob, Herb, et al,

Thanks so much for your input. You have eagle eyes -- and this forum is proving to be worth its weight in gold. I'm not an engineer and not even very mechanical, so you offered exactly what I needed.

I have no idea why I assembled the frame box wrong -- but I sure did. I was probably obsessing over getting it square, and when I finally got it square -- I quickly cranked the nuts down tight and forgot that they also had to be located in the right place. Will correct that right away.

I am aware that by going with encapsulated tail lights, I gave up the license plate light. I plan to mount a bicycle light with a battery next to it -- properly aimed and shielded. I also don't plan to use the trailer at night, at least for a year or so. But I suppose it is still illegal not to have the light there.

The extra support for the tongue below the frame gave me more pause for reflection. I hate mechanical work -- so I thought long and hard about it before doing what is probably a pretty simple fix.

Quote:
I would check with Trailex about making these changes and show them the pictures. IMO, I would have two more pairs of brackets (front and back) for added support from the box frame to the tongue of the trailer.
I grew up in the school of "If it's too strong, you'll never know it."

In the pictures the length of your box frame looks short. Was this changed for some reason or is this the way it's supposed to be?


Quote:
I share sEs's concern.

Originally, all the weight of your boat was being carried by the tongue resting on the suspension box. As you have modified it, all the weight is now being hung from 4 T-Bolts. I read somewhere that some people have had problems with the T-Bolts fatiguing the area in the channel that they fasten into causing cracking. With sEs's suggestion of two more brackets, you would have the weight carried by 8 bolts.



I pondered that a long time -- first to understand exactly what the difference was between the same brackets holding the tongue above the frame box vs holding it below. And second, to figure out if I agreed. Well, you both convinced me. In the tongue above position the weight of the boat & cradle cross bars is laying on the frame with the brackets only serving to hold it in position. In the tongue below position the weight is hanging on the brackets and thus on the bolts.

OK, but is that a problem? The boat and stowed gear and crossbars weigh, at most about 300 lbs (probably more like 200 for me most of the time). Three hundred divided by the 4 bolts is 75 lbs per bolt. Even if a weight were simply hanging from the bolt and bouncing up and down that would be -- what -- a few hundred pounds? I'm guessing that a 9/16 bolt is way more than up to the task.

But the weight is not really hanging from the bolt. The bolt's purpose is to squeeze the bracket against the frame. The weight of the boat is held by friction between the frame and the bracket. Actually, that is probably the case in either the tongue above or tongue below position. In the tongue above position, the holes in the bracket probably hold the tongue a small distance above the frame. TrailX would have had to spend a lot on precision machining to actually let the tongue rest on the frame.

So the the question in my mind is, Can a 9/16 bolt with the 35 ft-lbs of torque TrailX calls for, hold enough friction (would that be called torque? Don't know) so that 75 bouncing lbs would not slip? Again, I'm guessing that the bolt is up to way more than that. Herb, you suggest that the frame may not up to that amount of torque. But I've got to think that TrailX had that in mind in their original design.


Anyway, sEs won me over with that great comment, "If it's too strong, you'll never know it." That's my general approach to car top carrying, wrapping packages, etc -- which drives my wife nuts. So I called TrailX yesterday to order 4 extra brackets.

Ken answered the phone. He did not see that there was any difference between the tongue above the frame or the tongue below the frame -- even when I said that the tongue originally rested on the frame and now it hangs from 4 bolts. He also said that other customers have also moved the tongue below the frame without adding any additional brackets, and that they did not have any problems. So I canceled the order and went sailing for the first time in my life! What an incredible experience. I'm hooked!

By the way, I can now float the boat well up onto the trailer, rather than having to wade further out and lifting it up. Thanks again to all for helping me to think through this and work through it.

Puget


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PostPosted: Thu May 10, 2012 7:02 am 
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Location: Palm City, Florida
Puget,

Well that's the main thing; you've finally got your boat in the water, you've been out sailing and you're enjoying yourself. Congratulations!

I'm glad to hear that you ran all the changes you made to your trailer by Trailex. Have you checked your Tongue Weight now? That's the weight pressing down on the ball and hitch. It's supposed to be around 10% of the total weight of the trailer with everything on it. Now might be a good time to do this. You can adjust the Tongue Weight by moving the Box Frame forward for less, or back for more.

I don't think this is the last we're going to hear on this topic though. Currently Trailex lists their SUT-350-S for $1,112. The Hobie catalogue lists the SUT-350-AIT Trailex trailer for $1,311. It doesn't make sense to me either that you had to do all this to a brand new trailer that's supposed to be the right one for a TI.

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Sun E Sailor
Ezra Appel
Palm City, Florida
2014 Tandem Island


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PostPosted: Thu May 10, 2012 12:11 pm 
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Location: Puget Sound, Washington USA
sEs,

The tongue weight on the stock trailer (SUT-350-AIT) was, as I recall, about 90 lbs, or around 22% of trailer and boat & a little gear in the boat. I don't know exactly what the total weight is, but I'm guessing around 400 lbs. I assume that the 10% rule of thumb on tongue weight is a minimum. That is, the tongue weight should be at least that much, but more is OK. Might be a totally wrong assumption. I have no idea.

In any case, all my modification, including adding a trailer jack and a winch, lowered the tongue weight to 76 lbs. That would make it around 19%. But I'd also assume (perhaps wrongly), that the recommended tongue weight percentage of 10% is based on the maximum possible/allowable/GV weight, which the label on the trailer says is 490 lbs. In that case, the percentage is now 15% -- an improvement over the stock trailer.

I can easily move the frame forward to get 10%, but Tony suggests that a longer distance from vehicle to trailer axle makes backing easier.

Wish I knew reason for the 10% rule of thumb. Is it a minimum or maximum or average number, and just what is the percentage based on (actual or min or max load). For what its worth, I saw a trailer web site somewhere that said that for light weight trailers
the rule of thumb is 5 to 7%.

Thanks again for the help. Off to the water again. Sun and light winds predicted -- should be good for a beginner.

Puget


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PostPosted: Thu May 10, 2012 1:55 pm 
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Joined: Mon Jul 19, 2010 7:53 am
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Location: Palm City, Florida
Puget,

Here's what I went by when I set up my trailer.

TI:192 lbs.
SUT-350-S: 155 lbs. (your's might be slightly lighter)
Misc. gear: 50 lbs.
Aprox. total: 397 lbs.
Using the 10% rule as reccomended by Trailex, the Tongue Weight in this situation should be around 40 lbs.

You'll know how well your trailer is traveling when you get on the highway. I never go above 60-65 mph. You can find more information about all this here:
http://www.hitchingup.com/tongue-weight.htm
http://www.etrailer.com/faq-trailertowtips.aspx

Good luck and happy sailing.

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Sun E Sailor
Ezra Appel
Palm City, Florida
2014 Tandem Island


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PostPosted: Tue Sep 11, 2012 6:14 pm 
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Joined: Tue Sep 11, 2012 6:03 pm
Posts: 3
I did this rear roller modification to my Hobie Trailer from Trailex. Great idea!!!I just had to relocate the TI saddles forward 6 inches and uses PVC bushings instead of copper tubing so I could easily cut to exact length. It works great and with it do not have to get the trailer so far into the water to retreive boat. I also ordered a winch mount from trailex and mounted a 1000 pound strap winch so I can pull boat out solo on steep slippery boat ramps.


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