I am assembling a 1977 H16 for my first time. I have the manual from Hobie, but the photo quality is poor. My problem involves the orientation of the side-rails. The manual seems (?) to suggest the "flared" portion (where the tramp inserts) should be towards the front of the boat. But this does not make sense to me. I think it may be better with the flared opening in the side-rail towards the back of the boat. I have tried it (un-laced) in both positions.

Can someone set me straight here? Which way should it go ...and WHY? I don`t want to lace her up and have to re-do it again.


Dave

Here's a manual - it may be the one you have:
http://www.hobiecat.com/support/pdfs/H16_Manual.pdf

The flared ends of the rails go to the front - the grommets on the tramp go to the back. Lacing goes down the center and along the back. I have seen it the other way but that is unusual. Why? I guess this gives you more tramp in the front where the crew sits. Usually - you will find skipper and crew forward more than back on a 16 (unless it's blowin like snot).

better tramp pic

Good Luck

RQ

Hmmm, If I understand the situation right he is not planning on having the lacing on the front crossbar rather than on the rear. I think he is asking why the flared part of the side bar is facing towards the front of the boat. Actually this is a good question - something I assumed was not properly assembled on my boat. When I research the issue I learned that Hobie installed the sidebars in this manner because they were concerned that a sailor could suffer an injury by inserting a finger in the widened part of the side rail if it would be left exposed in the rear.
When I installed my new tramp I decided to disregard these concerns - Now my sidebars have the widened part in the rear while the front of the tramp is nicely supported in the extrusion. In order to avoid injury I inserted a piece of PVC hose that covers the flared area of the sidebar. Tapeing over the flared area would do the job as well. I will post some pics of my tramp … it is kind of a different approach to the one pice tramp (highly class illegal).

Patrick

Patrick,

You definitely "hit the nail on the head" and answered my question. You obviously had the same concern as to why the front/lateral corners of the tramp are clearly left unsupported when one follows the manual. But the real question is "why" and I believe you have answered that as well.

From a mechanical standpoint it seems the "open" or flared part of the sidebar is best to the rear(stern)- contrary to the manual. But for safey reasons, it is best toward the front(bow) - in accordance with the manual.

I will place it to the rear, just as you have, and plug/block the flared opening to protect fingers...Unless someone else can share a different view on this.

Thanks a lot,

Dave

Over time, if the flared part is to the rear, the tramp is more likely to pull out of the crossbars than if the flared part is to the front. Currently mine is with them to the rear, but it's still in the original configuration. When I get a new tramp I'll re-do it the other way around.

Jaime,

What you are saying doesn`t really make sense to me. If the flared part of the side-rails are to the rear, this effectively means that the tramp section up front and lateral is fully gripped by the side-rails. In the opposite scenario (flared portion up front), the tramp is clearly un-secured for several inches because of the flared opening.

What I don`t understand is how can the latter configuration (flared up front) possibly do a better job holding the tramp over the long-term as you suggest. Can you clarify this?

Thanks,

Dave

It seems to me like the only issue here is that the part on the flared area will not be supported quite as well. Since whoever's driving the boat is going to be sitting at the back, that area's more often going to need support. What advantage are you gaining by moving the flared area to the back?

Dave ... read Jim's posting again... he stated that the flared part in the front makes it more likely that the tramp would come out of the sidebar...

O.K. If you go with one of those "one pice bias cut tramps" than you would have to keep the flared part in the front to mount and remove the tramp - or you would have to remove the rear cross bar from the hulls and sidebars. (this is what I do for my version of the one pice)

Patrick

Aaronhoy is correct that the greatest strain to pull the tramp out of the slot is near the rear where most of the weight will be. My boat is in its original configuration with the flare towards the front and the only problem I have had of the tramp pulling out was in the rear in spite of the narrow slot. I solved it by putting a loop of the rear lacing through corner grommets and around the side rails. It has worked well for many years.

Howard

Patrick,

I just re-read Jaime`s post and I think you have misquoted him (although my brain is giving me trouble today, so perhaps I`m the really confused one). Jaime said:

"Over time, if the flared part is to the rear, the tramp is more likely to pull out of the crossbars than if the flared part is to the front".

It seems to me, this is opposite to what you are saying. Am I correct? Or...well...having troubles!!



Aaronhoy and HRT

I am fairly certain you are not really seeing the point here. Re-check the posts and look at your boat - the back (stern) portion gets no less or extra support with either setup. Only the front and lateral portion is affected.

Dave

Captain Dave,

Both Jaime and Aaronhoy are correct that the greatest strain to pull the tramp out of the side rails occurs near the rear. It is significantly greater since the conversion of the weight at that point to horizontal pull, gives a great mechanical advantage (increase in horizontal force). There seldom is much weight near the front bar.

In my previous post, I mentioned the loop of line I put around the side bar to retain the tramp in the slot. It works. If for some reason you wanted to reverse the flare and put it aft, you could use my suggestion to retain the tramp.

Howard

Howard,

You are correct in your physics but (I think) mistaken in your mechanics. On my tramp (stock hobie I believe) the flared opening in the side-rail does not even contact the trampoline whatsoever when it (the flared portion) is oriented to the rear of the boat(contrary to the manual). So, regardless of the forces being greater back there (true) it makes no difference at the stern at all in terms of trampoline support. It only changes things up front. Because if the flared portion is oriented up there, the tramp does have contact with it and of course it provides no support along those several inches.


Dave

Captain Dave,

I have gone out to look at my boat twice now and I think I understand your point. If the rails are reversed, the flared portion doesn't extend far enough forward to affect the support of the side of the tramp. In that reversed configuration the front of the tramp would be better supported. I have never had a problem with the front corner of the tramp but have with the rear in spite of the fact that there is no flare there. That is why I ran a line around the rail through the outside grommets. In any case the highest stress point is in the rear corner not the front.

Howard

That's interesting what you guys say. I'll have to measure the siderails again in a few months when I get back to my boat; I just feel like with the tramp lacing pulling on the grommets in the same place as the wide spot in the siderails there's an increased likelihood of the tramp pulling out of the siderails. I mean, that's where mine is pulling out right now, so I only speak from my own experience.

Howard,

I think you have it now. Yes, when the side-rails are reversed (flared opening to stern) the trampoline is unaffected by the opening because neither extends far enough to contact each other. The advantage to this arrangement seems to be that the front part of the tramp now gets full support where it did not previously (according to the manual). However, your point is well made insofar that there is little force on the tramp up front anyway...regardless of the setup. My feeling is, if it makes no difference at the stern either way (safety issue notwithstanding), then why not orient the siderails so as to give that extra support up front. The "holding" problem Jaime is referring to is obviously a real concern, but a separate one altogether, as it is not caused, or solved by the orientation of those side-rails. Perhaps Jaime has a different tramp. But the one I have could not possibly pull out of the flared opening if the opening is oriented to the rear of the boat(contrary to the manual). The tramp simply does not extend far enough back to even touch that opening.

...I actually never thought this issue would become so verbose. I just thought I had it wrong. I appreciate the input from everybody.

Dave

Ahh, now THAT makes a lot more sense. Now I see what you mean about the tramp not making it to the opening. In that case I guess it is technically better to have it reversed. For me though. I've never had support problems on the front, so it's not worth it for me to take the frame apart just to turn it around. If you already have the stuff apart though, I say go for it.