Super Jet How wide is too wide for sponsons? And My RN SJ build.

[btmboards]

I am working on refiberglassing my 96 RN. One of the thing I wanted to do was to widen the front of my tubbies that I already had on it. After mounting and using new pore foam they pushed out a bit wider than antisapated.
My question, how wide is too wide. Thanks.
Oh and I ride 100% surf

 

[special fx]

Wide is good!

 

[chasingdaylight]

Wide is good!

I see you like wide tubbies but not wide rails. I think i understand your point of having bouyancy up to a point then having it flickable with less rails. would you go for tubbies and having the rails wider where the larger tubbies were then tapering off as the tubbies do?? wow Your tubbies run all the way to the tray by the look of it is that correct... those are some long tubbies... Like your ideas

 

[btmboards]

Ya the way mine are shaped right now at the very front it butts up against the outter rail. If no one has anything negative to say about that wide then I will glass it seal it and try it out. If I like it then I will probobly at that point widen the rails.

 

[special fx]

I see you like wide tubbies but not wide rails. I think i understand your point of having bouyancy up to a point then having it flickable with less rails. would you go for tubbies and having the rails wider where the larger tubbies were then tapering off as the tubbies do?? wow Your tubbies run all the way to the tray by the look of it is that correct... those are some long tubbies... Like your ideas

Yeah, I like wide tubbies and skinny rails. I've ridden several skis with the wide rails and it's just not for me. It feels like a put training wheels and a nice high end mountain bike. My tubbies transition right at the center of gravity of the ski and it makes it handle very neutral and responsive. I'm hoping the current trend of super stable hulls goes the way of front exhaust and huge scupper valves!

 

[chasingdaylight]

Yeah, I like wide tubbies and skinny rails. I've ridden several skis with the wide rails and it's just not for me. It feels like a put training wheels and a nice high end mountain bike. My tubbies transition right at the center of gravity of the ski and it makes it handle very neutral and responsive. I'm hoping the current trend of super stable hulls goes the way of front exhaust and huge scupper valves!

Darn, wish i rode you ski befor starting my build. I talked to you through the x a couple of times.. me and tom21 that is i asked you about you width of tubbies but not the length. dam wish i called you and both rode your fx.. . I tapered my rails in contour of the tubbies... Hope i dont agree with you since i already did it..

 

[btmboards]

What is the most important part off the rail for stability/ floatation. I have seen a lot of people shave the front and rear rails, then I've seen people widen the sides, and I've head people talk about lengthen the drop on the rear. Could anyone give me a bit of a rundown on what the effect of these mods are. I've never ridden any other modded skis

 

[chasingdaylight]

What is the most important part off the rail for stability/ floatation. I have seen a lot of people shave the front and rear rails, then I've seen people widen the sides, and I've head people talk about lengthen the drop on the rear. Could anyone give me a bit of a rundown on what the effect of these mods are. I've never ridden any other modded skis

These are some hard questions .. because you get so many differant anwsers from differant people... because of differant skis and forms of riding.. .. remember special fx has many fx's and i believe he's done many mods to the fx's and tried many combo's his long tubbies i believe are changing the center of his ski and make it high when railing once it goes over center and has the roll effect better at that point. the wider rails will give it a stoping point and get less roll effect when in combo with large long tubbies and wide rails. . maybe normal tubbies and wider rails.
larger tubbies and less rail. i know people not running tubbies like the wider rails.. i did a combo of both tubbies not as long as his and more rail that tapers
just my 2 cents hope it helps

 

[btmboards]

How do you like the wider rails up front and tapering in the rear. I would like it to be real stable but at the same time be able to cut back around real hard. Here is the ski as I left it last night.

 

[btmboards]

I am still pretty new so I could use those training wheels for now. Then once i start figuring it out better I will begin to fine time everything out the way I want it.

 

[Crab]

No need to be wider IMO, they do the job very nice and the widened rail at the destroyer area helps carving also




.

 

[btmboards]

Well I got back from work today and didnt even go inside, just opened the garage and went to work. I really didnt plan everything out before hand but just kind of kept going. I have a bit of a tendancy to go to far with a lot of my projects but at the same time I pretty happy with the way things are going so far. Either way too late to go back now.
Currently sitting at shortened, rounded, reinforced, refoamed nose, extremly widdend sponsons, widdend bond rail in front and tapering back to the factory size in the rear, reinforced hull around engine compartment/ dash, bullet proof poll mount, shortend poll and reinforced at bottom near bracket. At this point I will be out of reson/epoxys and money. Really hoping that it will ride good.
I am open to any suggestions on things to do or ways to do it. This is my first build and I am really kinda flying by the seat of my pants on what I am doing.

 

[227]

Your sponson widening looks pretty similar to what I did.

Formed it up with cardboard- don't forget to put some release on the cardboard.

Poured two part expanding foam

Shaped sponson foam before glass

Shaped sponson foam before glass

 

[chasingdaylight]

How do you like the wider rails up front and tapering in the rear. I would like it to be real stable but at the same time be able to cut back around real hard. Here is the ski as I left it last night.

View attachment 161510View attachment 161511View attachment 161512

Ok those are some wwiiddee tubbies will be interested on how they work let us know..... I have not had this ski on the water yet still building. engine goes in today.

 

[btmboards]

John, looks like we did pretty close to the same thing, instead of shaping mine with cardboard though I used the tubbies to shape it. I pored the foam in between the two. Cut it down to size then concaved the foam in the middle to actually give me and extra cutting/carving edge. It the end though they will be fairly close to the same size. I am also going to have real wide rails around the sponsons that will fade back to match them. You will have to try it out when i get it done. As long as I don't run out of material I should be able to finish it by this weekend.

 

[tightithrash]

dude sweet!!! frekin going for it! i wanna ride it.

 

[sjetrider]

dont go any wider than the boat is long. Just sayin, my opinion!

 

[wydopen]

your gonna be bummed you cut the rail off around the nose..

 

[kevbo]

Squaring the rear edge will provide lift only. Raising and blending the trailing edge will pull down whenever they have flow over them. Tubbies are for cornering, square sponsons are for lift.

 

[Matt_E]

dont go any wider than the boat is long. Just sayin, my opinion!

Lol