Its public! Part of the new 66 Trail system, but this is on the north side of the highway behind the facebook data centers. Access is from Ochoco Viewpoint State Park. This is an intermediate level skills park, and Im about to start construction on an advanced level park in the next few weeks in the same spot.
sounds sick! if you need some hands let me know! just one town over
I got my first jump and landing built and it runs pretty smooth, it'll definitely be better once I build a roll in and get rid of the grass in-run (may be wishing the landing was a few feet further out though:
One problem I ran into though was the support failed: I mashed the brakes on a practice in-run when my foot slipped off the pedal it ended up ripping the 3" screws out of the 2x4 supports. Am thinking that maybe a pt 4x4 would be better then add some lag bolts to the 2x8 (ramp radius/side board) and perhaps some horizontal bracing? Does anyone have thoughts or experience with this?
A buddy built a calculator on Desmos that was pretty great for figuring out what the jump would look like: https://www.desmos.com/calculator/mvclxiz6od
also used this bike jump calculator from Trailism (new to me!) https://trailism.com/trail-science/jump-design/#jumpangle
and this from Omni calculator (awesome calculators by the way) https://www.omnicalculator.com/physics/inclined-plane
to think about how high to build in-run ramp. Am currently thinking 6'/2m with a 30 degree ramp off of it because it would be easier to carry speed down the shallower slope (vs 45) and onto the ground..
Anyhow - new to this and any constructive feedback would be most appreciated!
Looks like you're doing it all right man. Little details like gravel in the hole below the wood. Your skill and preparation is way beyond mine so i cant help. I just drink beers and do what feels right. Im sure someone here can give you good feedback on the engineering. Keep up that good work
Definitely beef the ramp up if it broke once, you don’t want it to break while you hit it at a faster speed. Deck screws should hold, you can get thicker deck screws also. The common ones are an 8
If you bumped up to #10 or #12 screws they will have a greater shear strength.
You need to attach the legs to the ramp. a 2x4 that will screw to the leg then lay flat on the ground and get screwed as close to the shallow part of the ramp. On both sides It will then triangulate the legs and the will be way stronger.
Currently nothing is tying the legs in horizontally where they meet the ground and they can easily break. I imagine they have a bit of wobble to them as is
Every thing else looks good on the ramp
As far as the roller angle I cant help I did mine to what looked right... then had to re do it.
You want the bottom curve of the downramp to have large radius, that makes it an easier transition to the ground and makes it more pump able for speed.
Nice work by the way- that is how my setup started way back when I was like 18
Definitely beef the ramp up if it broke once, you don’t want it to break while you hit it at a faster speed. Deck screws should hold, you can get thicker deck screws also. The common ones are an 8
If you bumped up to #10 or #12 screws they will have a greater shear strength.
You need to attach the legs to the ramp. a 2x4 that will screw to the leg then lay flat on the ground and get screwed as close to the shallow part of the ramp. On both sides It will then triangulate the legs and the will be way stronger.
Currently nothing is tying the legs in horizontally where they meet the ground and they can easily break. I imagine they have a bit of wobble to them as is
Every thing else looks good on the ramp
As far as the roller angle I cant help I did mine to what looked right... then had to re do it.
You want the bottom curve of the downramp to have large radius, that makes it an easier transition to the ground and makes it more pump able for speed.
Nice work by the way- that is how my setup started way back when I was like 18
Thanks! To the hardware store once the Black Friday madness passes...
@mrgonzo - once I get some experience I'll get to the drink beers and do what feels right but for now it's all protractors and tape measures