Backward tubbies & cut rail

[joelake]

Hey people, long time stalker on here, post little.

Hoping for some enlightenment from those who know.....

Being a long time kawi rider I have come back after a bit of a hiatus from stand-ups with a new to me pre 08 SJ. So far love it. Picked up with the pump out and in need of lots of helicoil lovin'!

It has a Carter rocker and carbon re enforcing in the hull (bit rough but who am I to judge!)and all the other things you would see on a surf boat. What I have noticed is tubbies that are installed backward?! And the bond rail has had the vertical lip cut off all the way around..... Now being a noob wtf is up with this? It seems to be pretty twitchy on flat water, and turning is pretty much all or nothing, might be just me.

I believe that this was built around 8 years ago, was this a thing back then?!

Thanks in advance.

 

[Sanoman]

Got any pics of the tubbies?
As far as the rails being cut,never heard about that being a mod,but others may chime in on it.The rails can be fixed with several layers of glass.Several guys have done that on here.More to modify a rail.Probably @hornedogg79 did one of the best rail mods on an fx1 that l have seen.Look him up

 

[FlyinRyan324]

Pics please. Sounds weird

 

[Freakie]

if the tubbies were installed with the lowest edge touching the lowest edge of the hull.....will turn extremely well but will be unstable at high speed on flat water (gets chine-walk)...whether they back to front or not....best overall effect is when they about 1cm above the lip on this RN
Vertical lip cut off the bond rail at the rear is best to use the rail as a skeg in surf, but useless to cut off all the way around.....could now damage the integrity of the hull under heavy landings, etc.

 

[joelake]

 

[joelake]

Thanks for the info so far. Here are some pics. Low quality sorry. Night time here.

I was debating if I should spend the time and effort turning the tubbies around or not?

Was thinking of maybe adding a rail sponson thing like those aluminum freeride innovation things that were going around.

 

[Big Kahuna]

I would rebuild the rails. Even make them a bit wider. With cut, when you jump any waves in the surf, the ski is going to sink down some when you land with the side cut off.

 

[jetx]

There not on backwards by the looks of it to me but they are too far back and placed all wonky. There suppose to go further up the nose but because it is rockered who ever Installed them placed them further back. There suppose to follow the shape of the hull. They will need modded to move them further forward and get them to where they should be with the rocker.

 

[Freakie]

Imho 100 percent on backwards I have done this job on that hull with those tabbies a few times and learned through my own mistakes....if they just bolted on. Just redo it no biggie

 

[Sanoman]

l was debating if I should spend the time and effort turning the tubbies around or not?

Worth the effort to turn around and do correctly! Listen to freakie and Big Kahuna

 

[joelake]

Yeah not sure what's going on with the rail cut. I am interested to see what difference it will make with a proper vertical of 45 degree rail hanging down. I am going to grab some aluminum and bend it at 45 degree and slap it on toward the rear to see what happens before I commit time to proper rail repair.

As far as the tubbies go, after reviewing pics online like jetx has posted (thanks btw) it seems that they are infact on the right way. The rockered front has made the placement to far back toward the rear. I am pretty heavy 220pounds or so. If I move these forward, will they make the front ride higher? This may be an issue for me yeah?

 

[jetx]

Coming from the Kawi to this rockered sj is a big handling change to what your probably use to, before you go through many extensive hull mods I’d try an extended plate first...may be what your looking for, help with stability and handling.

If you have the time, resources and skill set I’d address the rail issue first, and see how it effects the handling, I’m confident it will only be positive effects adding it back as they are intended to have one. If you still want more bite in turns you can go with some surf fins/rear sponsons, they made a good notable difference on my ski.

I would Move the Tubbies to there proper intended location, but I don’t think that’s solely going to change your desire for better handling. Shouldn’t ride any more nose high with them further up the nose, but dropping them down and forward will make them bite more in turns and how they were intended to be used.

It’s always a combination of the entire package...and like always tray time will let you get use to anything really.

 

[jetx]

I think the Measurement for the destroyer sponson placement on a pre 08 sj is 37.5 inches from the back, so that gives you a reference to see where they are actually placed on the hull.

 

[joelake]

Thanks for that. I am going to convert to mm and see what's up!

 

[subnsxr]

The rear sponson is a must. I just puked looking at the cut bond rail. My stomach hurts for you

 

[sxrchris]

Somebody really screwed up trimming the bondline. If you build that back up you'll gain stability at any speed. I've seen a sxr on here with it completely cut off. They said ski could not stay upright

Sent from my SAMSUNG-SM-J120A using Tapatalk

 

[hornedogg79]

I've done this to a few skis now and it's not so bad. Attach foam to the underside and carve out your new rail shape. Lay material on top. After it cures, remove foam and lay more on the bottom side. Trim to suit.

 

[Sanoman]

Listen to Hornedogg,he knows what he's doing! The fx1 pictured turned out strong and looking great

 

[joelake]

I am sure it's a pretty easy job to be honest, I am fiberglass/carbon proficient! The rails look good hornedogg, what is the point of the angled rails V's the verticals?


I have been riding this thing and I can't really say it's a huge issue now, it's not right but I can run it on on flat and in surf. I have bent up some aluminum (2 foot, 45 degree "rails") to bolt on for the season here (don't have time to really tear it up now, waste of a good summer!) To see how much difference it makes, I will report back.

As far as the tubbies go they are a couple of inches rearward of optimal mounting, but I am not going to screw around with them for what I may get out of it would be little I could feel anyway.

 

[joelake]

I went ahead and bolted on some death find I made.


Wow..... Such a huge difference. I just cannot understand why these rails were cut. It was like riding a bike on ice before compared even to these 60 degree rails on the side now.


I will see out this season and over winter glass some rails on proper front to back.


Thanks for the help everyone.....