Building a Hidden Backyard Bike Jump

Building a Hidden Backyard Bike Jump


Last week, we built a new trail here on Berm
Peak. It was a short one, starting at the top of
Woodpecker and ending at a row of shrubs behind the garage. The trail is named Airbag, which seems appropriate
for a run with an emergency stop at the end, but we’re not quite finished with this trail. Eric travelled all the way from Utah to visit
Berm Peak, and I’m having a great time showing him what we’ve built here. Eric has a trail system in his yard too, although
it would be more accurate to call it a slopestyle course. Only a few trees hide this course from his
patio, the one tiny sliver of his backyard that isn’t covered in jumps. And I have good reason to keep my yard looking
normal too. I promised Mrs. Bike Hacks that all the trails,
jumps, and features would stay in the woods, behind the trees. Today’s build will certainly push the boundaries
of that agreement. Today, Eric is helping me design build a huge
jump which will be hidden behind these bushes. Of course that does put the trajectory of
anyone riding this jump, squarely on the lawn behind the garage. But I have a solution for that. For now, all we need to do is build the lip. A lip is a curved launch made from dirt, wood,
metal, or anything really. Our lip will be 6 feet tall with a 10.5 foot
radius. That radius will make a transition from the
ground to a certified bike cannon. To make sure we get that angle exactly right,
I drew a guide which we can use later on with a level. This transition is just mellow enough to cut
with a circular saw, which makes for a really smooth cut. But since we’re using 2×12 lumber, we’ll
need to join a few pieces together in order to make it a full 6 feet tall. To join the sections, we line them up very
carefully and use a scab to keep them in place. A scab is just another piece of wood fastened
to the outside of both pieces. Once we actually install this lip on the trail,
it’ll include additional supports at this junction to help support the weight of the
structure and the people riding on it. Now that we have the pieces joined together,
the scale of this lip is really starting to sink in. Back on the trail, we need to do a fair bit
grading to get the approach right. We also need to dig down so the front of the
lip meets up with the trail. Because the whole trail is going downhill,
we also need to contend with the angle of the lip itself, which requires even more digging. It’s a good thing we built the approach
last week, because this part ended up being a lot more work than we originally anticipated. It also ended up being a lot more complicated. The
original flag line of the trail put its path right between the garage and a bunch of trees. In the woods, I tried to get everything as
straight as possible without cutting down any live trees. Now, we’re left with a deceptively narrow
margin to get the lip angled right. We need to make our measurements, dig down,
and then hope everything remains in the same spot when we drop the lip in place. Here to help us with the final stages, is
Joe. He’s a long time friend of Eric’s, and
actually a neighbor of mine. To do this alone or even with two people would
be challenging. You need to hold a giant transition in place,
measure it, and fasten it all simultaneously. So you either need three people or six really
long arms. While Eric and I finish up the construction
of the lip, Joe is making some adjustments to the area behind the bushes. This really pushes the boundaries of my no
building in the yard policy, but it’s technically still in the woods, right? Although it’s not ideal, we cut away part
of the lip to preserve this large tree root. This could eventually cause a problem with
the lip, but the whole point of this project is to hide the lip behind trees and shrubs
so we need to make some compromises. All in all, it took about a day and a half
to get our materials, settle on a design, grade the approach, and build the lip. Now that it’s done, we get to see if this
lip is any good. Yep, I bought an airbag lander. It’s not like I kept it a secret though—the
trail is named Airbag. But it’s possible that some of you didn’t
know that landing airbags are even a thing. You don’t see a lot of wedge shaped bouncy
castles in day to day life. But while the airbag is as awesome as I imagined,
our airbag experience didn’t start out so smoothly. There was a learning curve. We were also riding our lip for the very first
time and trying to gauge speed. Naturally, I did the honors. This is only the most recent instance of me
not listening to Eric, but to be fair, I don’t listen to anyone. Eventually we got the speed thing worked out,
and by then it was starting to get dark out. But we had a list of things to work out for
the following morning. First, we covered the drainage trench with
3/4 plywood so the bottom of the landing would sit flat. That was causing a sort of double bounce on
day one, and the plywood solved it. Once we got that taken care of, we went back
to make some adjustments to the lip. Because of the slope, the lander was a fair
bit lower than the lip making it difficult to see when approaching it. We went back and forth, first removing two
planks from the top, and then trying it again with only one removed. We kept testing it, making adjustments, and
discussing it. Eventually, we settled on making the lip one
plank lower than the original plan, and everything felt perfect. That put us at about 5.5” feet with a 10.5
foot radius. With the lander about 10 feet away, this is
actually a really mellow jump that you don’t need much speed for. That’s kind of what we wanted since we intend
on doing tricks off this thing. But we still had a lot of mistakes to make. At first, we were afraid of running the airbag
too firm, since it might actually bounce us off of it upon landing. So, to dampen the bounciness we experimented
with the air flaps and got it to where we thought things would run smoothly. At first, things did run smoothly, until they
didn’t. I guess the flaps must have blown open because
the airbag was collapsing so much that Eric’s pedals dug into the cover and stopped his
bike completely. The same thing happened to me. Eventually we realized that closing the flaps
and running it super firm was actually the way to go, but we sure did learn that the
hard way. It’s worth mentioning that the lander has
this big heavy duty cover on it that protects the airbag from pedals, handlebars, and teeth. Among these learning experiences, we did have
some big wins. Although I was unable to throw any tricks
on day one, Eric and Joe were getting really comfortable. The jumps at Eric’s house are designed for
dirt jump specific bikes, which are small, simple, and optimal for doing tricks. But with the airbag there to cushion a potential
fall, Eric took the opportunity to try those same tricks on his full sized Diamondback
Release. With a storm headed our way we needed to pack
up and call it. But we crushed our objectives. Now, there’s a big jump on Berm Peak and
it’s totally hidden from view, assuming the airbag is packed up. I plan on using this airbag a lot. I never had easy access to a good trick double
before, so now I can spend some time and actually learn some tricks. Without Eric and Joe to help out, this wouldn’t
have come out as good as it did. So thanks to both of you guys for helping
me build what is currently, the most ridiculous thing on Berm Peak. Check out Eric’s channel to get a behind
the scenes look at his trip here. Until then, thanks for riding with me today
and I’ll see you next time.