[Savage_Animal]

I'm building a jump in my back yard mainly for just practicing like tricks and stuff since I can always go out to the trails to actualy ride. I only have enough room for one jump so i'm planning on make a nice kicker with a just a soft dirt/wood chip landing so its a big deal if I fall.

It will be right here:

the quarter will go on the opposite side of the sport court to drop in from and the kicker will go right where it is, the landing will be infront/on the grass with a burm right infront of the fence.

So pretty much like this except that the landing will be boarded in:
http://www.pinkbike.com/video/32320/

1) So say the kicker is going to be 5 feet tall and 4 feet wide. For that height, what is a good radius? I was thinking between 8-10 feet?

2) How long should the landing be (ie. what slope) and should it be the same height as the kicker or taller?

3) Is 8 feet wide enough for the landing (the qp in the picture above is 10 feet wide)?

thanks.

 

[aeffertz]

If this is a trick jump, I wouldn't board the sides of the landing, for obvious reasons...
If you/your parents are worried about getting dirt all over the yard, just put a tarp down where you will be dumping all you dirt.
For the landing, I would just wing it. Build a normal looking landing, and tweak it once your ramp is finished and you've gone off it a few times.
Go with soft dirt over wood chips. Wood chips hurt like a bitch if you fall on them.

 

[Damo]

I'd spraypaint it silver. That would be well trick.

 

[cmc]

I say build a regular box jump (launch/deck/large landing).

If you want a "resi-landing" (watch some woodward videos to see what i'm talking about) then put some kind of padding on the landing, like gymnastics mats.

http://rampplans.org/forums/?board=rampreq;action=display;num=1153523670

Even though the ramp in this pic is rad... You really don't need a box jump launch to be 12 feet wide. I have seen people make the launch 4 feet wide....then you make the deck triangular...so that you have an 8-12 ft. wide landing. if you are going to learn 360's, it's a good idea to go wider than 8 ft. on the landing.

For a backyard setup where you don't really have room to crank for speed, you are going to need about a 10 or 12 foot tall roll-in / flat bank / quarter to get speed.

 

[Savage_Animal]

Thanks for the replys.

I need it boxed in. I don't think hitting the sides will be a problem. I already have 360s down where I'm not going all over the place so i'm sure its fine. So basicly you think 8 foot is a good radious from looking at those plans?

I drew some of my own, for some reason google sketchUp won't work on my computer so this is with paint:

Everything is in feet.
So I need to know what lengths A,B,C, And the radius should be.

 

[WestCoastHucker]

I'd spraypaint it silver...

that sounds hella trick...

 

[joelalamo45]

8' radius for a mtb will be really tight. Go 10' for a 5' tall ramp.

 

[grom-dom]

every jump is a trick jump.

 

[Cru Jones]

8' radius for a mtb will be really tight. Go 10' for a 5' tall ramp.

That's crazy talk... unless you're going really, really fast, or want to go really, really far. :biggrin: Anywhere from a 7.5' to 9' radius should be good. If it were me, I wouldn't use a constant radius. I would draw the transition by hand with a slightly decreasing radius as you go up... for maximum boostitude. Or, you can use a string and a pencil to do that by having the string wrap around something as it swings up the arc.

 

[Cru Jones]

Also, if you have to board in the landing, I would put in a case deck on top... you don't want to land on that corner. A foot or two deep of deck would be good.

 

[joelalamo45]

That's crazy talk... unless you're going really, really fast, or want to go really, really far. :biggrin: Anywhere from a 7.5' to 9' radius should be good. If it were me, I wouldn't use a constant radius. I would draw the transition by hand with a slightly decreasing radius as you go up... for maximum boostitude. Or, you can use a string and a pencil to do that by having the string wrap around something as it swings up the arc.

The last box jump for bmx that we did shows on was a 9' radius and 5' tall. The Crankworx tranny's are 12' for a 6'/7' ramp.

Just sayin.

 

[grom-dom]

i like tight, steep tranny. gotta go fast to clear it. maximum boostitude

 

[Savage_Animal]

Thanks cru. I never thought of a deck on the landing. That sounds like a good idea.

Still trying to figure out this radius. The crankworx jumps have like 30 foot gaps, so they obviously have a shallow slope. I'm thinking 8 to 9 feet, but hand drawing it might be good too. I could trace one side on to the other.

 

[aeffertz]

My ramp I just built just about goes vert. (bmx)
4' tall and I don't know what the radius is though... Tight.
I'm going to go so high, I'm pumped!

 

[Cru Jones]

Maybe this will help. I sketched up the different radiuses (radii?) on SketchUp.

7 foot

8 foot

9 foot

10 foot

 

[Cru Jones]

The last box jump for bmx that we did shows on was a 9' radius and 5' tall.

Yeah... but, that was probably the first box jump ever made back in 1982. :biggrin:

 

[aeffertz]

That's the one I just finished building... Should go pretty damn high. I'll measure it's radius tomorrow because I'm pretty curious...

 

[builder666]

I'm thinking 8 to 9 feet, but hand drawing it might be good too. I could trace one side on to the other.

I lay out the radius using a 2 x 4" x 6-12" longer than the radius, with a stadic pivot and a pencil fixed to the end, at a distance from pencil to pivot = to the radius. Doing it this way requires you to line up the swing with both tip to top.

Cutting the side: I like to screw the lumber for both sides together and layout once, then cut both sides once.

 

[joelalamo45]

If you go 7' radius your jump will suck balls on even a 20. The Crankworx gaps were only 10' and 14' so I'm not sure where they even remotely look like 30'. My personal box jump at home is 6' tall with a 12' radius (to match the Crankworx Colorado jumps). Granted, on a 20 they are really mellow, but on a 26 they are pretty good for high speed sleddin. Any good skateparks box jump has a 9' or 10' transition. The skatepark I always frequented in Dallas tore down there old box jump with an 8' tranny and replaced it with a 9' tranny, 5 1/2' high, 10' deck... and that thing is geared for 20's. Keep in mind that your 26 is going to make the transition feel smaller because of the bigger wheels.

These other tards on here are trippin if they think a 7' tranny will be worth a sh!t on a 26 :biggrin:

 

[cmc]

not done well b/c in MS Paint.... but maybe this would help visualize... i agree with joel--a 7 foot radius on a 5 foot ramp would be very steep for a box jump--but that's a rider preference issue. i would go with 8' or 9' radius depending on whether you want to go high or far.



ELLIPTICAL radius, vertically eliptical:

ELLIPTICAL radius, horizontally elliptical:

 

[aeffertz]

Someone tell me how this is going to work.

My ramp is a few inches shy of 4' tall, and has a 4 foot radius. It looks a lot like my dirt jumps, but again, I could be wrong.

 

[cmc]

Someone tell me how this is going to work.

My ramp is a few inches shy of 4' tall, and has a 4 foot radius. It looks a lot like my dirt jumps, but again, I could be wrong.

At least from that picture, I would say that ramp does not have a 4 foot radius. How did you measure it ?

 

[aeffertz]

I used a tape measure.

 

[Savage_Animal]

Maybe this will help. I sketched up the different radiuses (radii?) on SketchUp.


9 foot

Thanks a lot for doing that cru. your the man. I think the 9 foot looks like the best bet. And that also answers my question about how long it should be. Sweet, I'm stoked on building this.

One last thing I want to know; I could probly try and figure this out on my own, but does anyone know how long the landing should be if its 6 feet tall?

 

[cmc]

I used a tape measure.

lemme explain what i meant.... if a ramp is 4 feet tall and has a 4 foot radius, then it is literally shaped like a quarter of a pipe, and willl go all the way up to vert. this would be very tight and hard to ride, even for a skateboard. your ramp looks like you could continue that same curve up another 2 feet before getting to vert, meaning you more likely have a 6' radius. radius is not the surface of the ramp.... it's the length of string or 2X4 in red below used to draw the curve...

... sorry, u probably already know that... your ramp looks well done and will be fun to ride. everything is rideable!

Example of quarter pipe that goes exactly up to vert. Pretty sure this was 8' tall, 8' wide, 8' radius/transition. Right Joel ?

 

[Cru Jones]

Thanks a lot for doing that cru. your the man. I think the 9 foot looks like the best bet. And that also answers my question about how long it should be. Sweet, I'm stoked on building this.

One last thing I want to know; I could probly try and figure this out on my own, but does anyone know how long the landing should be if its 6 feet tall?

No prob. I like doing that kind of stuff. As for the landing length, that's really just personal preference on how steep you want it. It's not setting you up for another jump, so you don't really need it to be steep. Somewhere around 10 feet, plus a foot or two for the deck would probably be good.

 

[Cru Jones]

Someone tell me how this is going to work.

My ramp is a few inches shy of 4' tall, and has a 4 foot radius. It looks a lot like my dirt jumps, but again, I could be wrong.

That's def not a 4' radius. Like CMC said, it would go to vert if it was. Do you know what a radius is? How exactly did you measure it? That would be hard to do after the ramp was built.

 

[opjones]

I did 9' rad. on my ramp, it's great. I went 4' 5" tall, I should of went taller for more boost, but it's all good.

 

[aeffertz]

lemme explain what i meant....

Thanks for the info. I will admit that I knew that you were looking for that kind of answer, but I was kinda in a hurry so I typed that. Here's how I measured it.

Red line equals what I measured. I see my mistake. The ramp doesn't go completely vert, therefore, the radius will be shorter.

Here's an exact side picture of the ramp. Seems like it's just what I'm looking for (more height, less distance) but I'm just afraid that the curve is to sharp; like I'm going to get kicked really bad.

 

[Savage_Animal]

Final plans for my trick jump:

The tops of the sides of the landing will be covered in those foam noodle things for the pool. And I'll put a 1 foot deck on top in in case I hit it. Sound good?

Ohh I can change it but what would be a good gap to look at setting it up as?

 

[joelalamo45]

Example of quarter pipe that goes exactly up to vert. Pretty sure this was 8' tall, 8' wide, 8' radius/transition. Right Joel ?

Yep. All the old bmx comps had 8' tall by 8' wide ramps with 8' transitions.

By the way. Rick Moliterno always rode the sickest bikes when he was on Hutch. That candy red Trickstar was the sikkness.

 

[VPFreerider]

http://www.ridemonkey.com/forums/showthread.php?p=3069407#post3069407

My lander is roughly 5ft tall and 9ft long. I added a 2ft deck onto the lander after the pictures were taken. Makes it much less intimidating haha. I would probably have added another foot or so of length to the lander if I had to do it again but I'm more than happy with it as is

 

[cmc]

Final plans for my trick jump:

The tops of the sides of the landing will be covered in those foam noodle things for the pool. And I'll put a 1 foot deck on top in in case I hit it. Sound good?

Ohh I can change it but what would be a good gap to look at setting it up as?

Most people who build wooden box jumps build an actual platform (deck) connecting the launch to the landing. It's very rare to see it dirt jump style, with just a big gap then a wood landing. Not saying you can't do it, it's just odd. At least if you ditch the bike mid air and bail, with dirt you're landing on something relatively forgiving and mound shaped. With a wood landing you're liable to knock all the teeth out of your face, break ribs etc.

So at least put a 4 foot deck in there, then pull the launch back if you want to.... But better yet, a full sized deck. 8-12 feet depending on what kind of speed you'll have (not much b/c you're in a backyard)

 

[Savage_Animal]

Most people who build wooden box jumps build an actual platform (deck) connecting the launch to the landing. It's very rare to see it dirt jump style, with just a big gap then a wood landing. Not saying you can't do it, it's just odd. At least if you ditch the bike mid air and bail, with dirt you're landing on something relatively forgiving and mound shaped. With a wood landing you're liable to knock all the teeth out of your face, break ribs etc.

So at least put a 4 foot deck in there, then pull the launch back if you want to.... But better yet, a full sized deck. 8-12 feet depending on what kind of speed you'll have (not much b/c you're in a backyard)

Sorry if I wasn't clear enough but the landing is filled with mulch and dirt, hence the"trick" jump. Not just a wood landing like in the other thread.

But ya i'll just start with a small gap and move it back.

Thanks everyone for the advice I'll psot pictures of the progress in this thread so stay tuned.

 

[joelalamo45]

Yeah... but, that was probably the first box jump ever made back in 1982. :biggrin:

Don't hate on me just because I was collecting checks at 15... :biggrin: