Dirt Jumping Formula

Discussion in 'The Adrenaline Factory' started by BFloFoxRider., May 10, 2009.

  1. BFloFoxRider.

    BFloFoxRider. Active Member

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    So, when building Dirt Jumps, is there a basic formula to make them correctly?
    I know you build tabletops, the landing is supposed to be 3 times longer than the takeoff is high, or something like that.

    Is there a way to determine what a good angle of the lip should be, and how much of a distance between them there should be?
    Thanks in advance.
     
  2. Chewyeti

    Chewyeti Circus Bear

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    Physics.
     
  3. bwolmarans

    bwolmarans The perfect look.

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    no "basic" formula that I know of, but I know a complex one:

    v=d*(sqr(g/((2*Cos(a))*(d*SIN(a)-h*cos(a)))))

    Where:
    v = speed at launch (fps)
    g = 32.2 (gravity constant - acceleration rate of ft/sec/sec)
    d = throw distance (ft) = x
    a = launch angle (degrees) = 45
    h = height of landing point relative to point of impact = -1

    Simple and less nerdy:

    If Jump is like a flat ramp < 45 degrees the landing can be as far as you can fly, obviously.

    If Jump is curved and > 45 degrees I would not make the landing further than twice the height away, see this pic for an idea

    [​IMG]
     
  4. strobelite

    strobelite Banned

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    build it and then make your little brother test it first.
     
  5. Ride2live32

    Ride2live32 New Member

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    :lol::lol::lol::lol::lol::lol: thats what I used to do.. hahaha..

    But yeah Brandon, we have DJ with wood ramp in our backyard if your interested in try and learn.. I build these ramps out of plywood, 2x6.. (used to work for "build to shred"'s friend and learned about ramp building there a long time ago) and I used to dirt jump bmx. Its not that hard.. you need to figure out how fast you can go on the trail, then mark where u feel more comfortable putting launch ramp at, and make sure landing has enough room to slow down before wall if there is any. Although its always better to have landing taller, and longer with huge radius at almost end of landing instead of flat into flat.. [​IMG] we still are building the landing bigger.
     
  6. Rockinthecasbah

    Rockinthecasbah A.D.D. Unleased

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    the steepness of the landing depends on how steep the lip is and if its a single jump or a pack. If the lip is going to throw you way high the landing needs to be steeper so you dont compress to hard when you land. If its a booter lip thats throwing more distance you can level it out a bit .build it, ride it, see what happens
     
  7. BFloFoxRider.

    BFloFoxRider. Active Member

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    If you are interested, i have a space about 80 feet by 20 feet to build stuff on, with a good 40+ foot cement run in (this is my backyard), my dad said its ok as long as the ramps were moveable in case we ever needed to move them. If you want to come maybe plan something out, of if i take opics and sent them to you, if youw anna help teach me to build stuff, i could talk to my dad and i'm sure he would be fine with letting you ride it when i'm home...
    Pm me and we can talk?
     
  8. FyrFytrRyn

    FyrFytrRyn RTB to a WNL

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    DJ formula.
    bobcat+water truck-rocks(friends)= DJ
     
  9. bwolmarans

    bwolmarans The perfect look.

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  10. BFloFoxRider.

    BFloFoxRider. Active Member

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    I'm gonna start buildning a Takeoff tonight..... :)
     

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