Rear surf fins?

[redwood]

Whats the deal with surf board style fins on the rear of the foot rocket and a couple of other aussie skis?

 

[jhall752]

it let you hook into the wave when riding down the face in the critical sections

 

[227]

A Footrocket has Fins? Post a pic of that. Or do you mean fins on the rails?

 

[camojoe]

A Footrocket has Fins? Post a pic of that. Or do you mean fins on the rails?

Here are some pics of Krash Ind. JB 1 with 'rear sponsons' on the rails

BTW...Krash Ind calls them 'ripper fins'

 

[Big Kahuna]

They are called Rear Sponsons to be precise.

 

[227]

Here are some pics of Krash Ind. JB 1 with 'rear sponsons' on the rails

BTW...Krash Ind calls them 'ripper fins'

View attachment 206399View attachment 206400

AH Yes! Fins on the rails. We experimented with that a few years ago. Not a game changer but they worked OK.

 

[wydopen]

step on the tail harder lean it over and gas it if u cant get it to hook up..

 

[djraider700]

I experimented with this idea on my SJ. The change in feel is there but it's so subtle that I took them off. I've ridden a JB1 with them and it was the best AM ski that I've ridden. Of course I don't think it was all due to the fins. Those Aussies know a thing or two about what works though.

 

[naithgroves]

If I take my fins off I hate surf riding a wave it's just not as fun because you need more weight and gas on the working side this slows my quick turns down BIG time.

 

[227]

If I take my fins off I hate surf riding a wave it's just not as fun because you need more weight and gas on the working side this slows my quick turns down BIG time.

Not sure what your riding spot conditions are like but at our spot the waves are more rollers and rarely break top to bottom. When we experimented with the rail fins they worked best in the more critical sections. However since we rarely get critically shaped surf we discontinued using them, which is why I said they worked OK but they're not a game changer (at least for our spot)

 

[Idok]

its nothing new..

 

[camojoe]

http://www.freerideinnovations.co.uk/freeride-surf-fins.html

 

[Sharky]

WORX has made rear fins for years , here is a pic... we put some on a FP1 and it is noticeably different , harder to spray your mate in the face with a jet pump LOL , but i like the feel on the side of a wave... can't comment on the deeper fins but the WOrx ones are longer and will place more force on the rail as they are aluminium and longer ... different strokes for different folks

 

[Big Kahuna]

I ran similar ones on my SXR. Great handling mod. Never noticed any on SJ's at the time.

 

[Vumad]

I run long shallow ones on my superjet. Much improved handling. The boat still slides nicely when it is flat, but it keeps the back end from kicking out while I am turning hard. Mine are nothing like the ones in this thread. More like the TBM race style. I know from waveboarding that a long shallow fin gives just as much hook up as a short deep fin.

Speaking wakeboarding, Short deep fins reenter the water aggressively and kick you hard when you are doing powerslides, butter slides and rotations. Anytime you break the fin out, they reenter very rough.
Long shallow fins don't hit the water as soon or with as much leverage. But, they give you just as much traction because the same amount of fin is in the water, Actually, more traction, because they have more leverage to keep the board straight. You loose traction sooner, but that is good, because you are trying to spin or slide.

I found on my superjet that my sponsons help a lot. They reduce the sway in the back and grealy improve stability. Like how front sponsons eliminate roll, rear sponsons eliminate sway. However, like front sponsons, you can still make it roll with a little more effort. The back end of the ski still swing around, it's no different than breaking the fin of the wakeboard free. It take more effort to do the trick, but you have much more controlled set-up

Mine measure approximately 22" long and are about 1.25" below the bond rail. They have a long sweep to them. The tail of the sponson that I have doesn't matter that much, every curve does something a little different and wont translate directly from wakeboarding. If you are looking for something pre-made, TBM has a good set.

I haven't had time to try out too many fins, and we don't have the killer surf they have in Austrailia, Cali or even the US Easy coast to test, but so far I have been pleased.

I messed up and made mine 2 short. It was my intention to use the stock bond rail holes to hold them on, but I was working fast and failed to account for the tail of the fin. I should have made the upper mounting portion (or the whole fin) 1" longer so it would have reached that forward mounting position. Make sure if you have turf, you run fender washers.



I feel like deeper fins would let me carve harder, but would prevent me from sliding and spining more.

 

[masterblaster]

how does the fin effect the way the ski rails hard on corners. I was thinking of using a fin,at a slight angle outwards towards the front of the fin then sweep it backwards a tad at the rear to keep a wider hull pulled over and railing hard

 

[Poizen]

the fin acts like a pivot point it changes the handling if you move it forward or back

i like mine far back you can corner super hard and it just grips

perfect for surf

here is mine

 

[masterblaster]

poizen,have you ever tried adding spacers behind the rear or front of the fin to change the angle in which it contacts the water on a hard bottom turn on a wave or a simple railing flatwater turn? Kinda like the angle the outside thruster fins have on a surfboard

 

[Poizen]

yes ive had them at 90deg to hull but i didnt like it now they sit at a angle outwards about 20deg to widen the stance alittle

 

[Mr Bojangles]

I widened and put my rails at 40* and love it in the surf, they dig down more in the rear with less effort, but put a bit of weight forward and it breaks free with ease.