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  1. #1
    home of the dislexic fingers breon's Avatar
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    sponson placement and affect

    looking 4 input based on your expieriences.... on how moving or changing sponson placement... front to rear .. well as up and down... blade depth below the side of the ski ..channel depth... and width affected your ski ...i am working on a set and trying to tune them in ... i noticed most skis sponsons are at the very rear... rxp and rxt are forward a bit due to the opas ....looking at the race skis..it seems quite a few i have seen have extra blades towards the rear ...the zapata hull has eliminated the opas cut outs and moves the sponsons toward the rear .....rules say max extension is like 4 inches from the side that seems real wide ...what are racers looking for ....it is my understanding if you get to much bite you will loose all your momentum through the corner ....what charicteristics are we looking for ..understanding the handeling is subjective


  2. #2
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    Quote Originally Posted by breon View Post
    looking 4 input based on your expieriences.... on how moving or changing sponson placement... front to rear .. well as up and down... blade depth below the side of the ski ..channel depth... and width affected your ski ...i am working on a set and trying to tune them in ... i noticed most skis sponsons are at the very rear... rxp and rxt are forward a bit due to the opas ....looking at the race skis..it seems quite a few i have seen have extra blades towards the rear ...the zapata hull has eliminated the opas cut outs and moves the sponsons toward the rear .....rules say max extension is like 4 inches from the side that seems real wide ...what are racers looking for ....it is my understanding if you get to much bite you will loose all your momentum through the corner ....what charicteristics are we looking for ..understanding the handeling is subjective


    Consider them mounted in the middle (even front/back), as NEUTRAL....

    Farther forward, the ski turns on center, meaning the pivot point is more towards the center of the ski....Imagine reactions like that sit-and-spin as kid....

    Farther back, the ski turns on its rear, meaning pivot point is more towwards the back of ski...Imagine turing a shopping cart with arms fully out...

    Blades up, less drag, less grip....
    Blades down, more drag, more grip...


    Fine tune from there...

  3. #3
    jaycee's Avatar
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    And the award for the most simplistic yet awesome explanation goes to....


    Danny, that was awesome. I knew nothing about changing sponsons placement and now I feel like I know why they do what they do and how to change the feel of the ski....


    Awesome!!!

  4. #4
    home of the dislexic fingers breon's Avatar
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    great analage

  5. #5
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    Welcome guys...Just play around, because the setting you least expect MAY respond to YOU BETTER...

    I've built so many and tested in so many configurations, it all comes down to personal preference on how the ski responds to your riding style....Things like sitting normal with feet forward makes the ski handle different compared to sitting normal with feet facing backwards, YOUR center of gravity will make the ski react differently...

  6. #6
    please explain the spinning id and the shopping cart again
    anyway, I made a 8mm backing plate in the exact shape of the oem sponsen.
    now they are 8mm further out and dropped in the back 20mm and in the front 16mm.
    THIS IS UNRIDABLE AND DANGEROUS!!!!
    After I sanded down the little hook at the rear part of the sponsen, now they are straight through with no hook, they became perfect!!
    They corner sharp, maybe a little agressive, but perfect for CC racing
    I will try to move the back up by 2mm and see if this is makingit a little less agressive
    Please let me know the things you've tried and how it performed?
    Cheers

  7. #7
    home of the dislexic fingers breon's Avatar
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    i have a 07 rxp.. stock.... i didnt like it... it didnt seem to turn... i was used to the old xp 650 ...that thing would turn so hard you couldnt hold on ...stock my rxp seemed to slide through turns more like a sprint car....a little to much and you were around ..it was a new ski and i was buying stuff as fast as I could afford it ...i made pro opas block offs and i redrilled the stock sponsons and lowered them about 1/2 inch ..the ski definately turned much harder i think the second hard turn i flew off ... but the ski turned great i ran it like that 4 awhile ....now i have made some new ones and i moved them back at first they were in the up position and it tracked great through the chop.... it was rough out... but the little flat i could find it didnt bite as hard as before...so the next week i lowered them down.... the mounting plate is 1 inch thick the sponsons are 1/2 inch thick everything is ronded to the outside the mounting plate is flush with the edge to the bottom of the side of the ski ...and stick down 1 3/4 total length is about 32 inches but the blade that sticks in the water is only about 22 inches...unfortunately it has been so rough i havent been able to set up the bouies and play ...i just got my skegs today so that will also change things ...what are charicteristics of skis that go fast in cc races do they slide through or carve hard ...??? this is what i have so far still testing to find what i like
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  8. #8
    home of the dislexic fingers breon's Avatar
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    arg allways get the wrong one i guess i need to go through an name them # arnt cutting it
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  9. #9
    Got Boost? psycho rxp's Avatar
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    Skegs will help in smooth water for straight line tracking, and provides more lift for speed gains. They track awesome in rough water, but I noticed they tend to make u come un-hooked much easier at speed. Be careful doing high speed tight turns.....It WILL Suprise u!!...lol

  10. #10
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    I forgot to ask, did you incorporate camber into the backing plate, about 7.5-8 degrees? if not, and the backing plate is flat to the hull, presenting a mirror'd angle for the blade, then they are pointing inward and it will majorly affect handling...

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