Building a huge portable bike jump that fits in my Honda

Last month we built a large wooden lip behind a row of shrubs, for use with my airbag lander. And.


Last month we built a large wooden lip behind
a row of shrubs, for use with my airbag lander. And as it turns out, we use this airbag jump
a lot—basically any time we can. But as the season wears on, the ground tends
to stay mushy for days after it rains, and for hours after the morning freeze thaw. Riding the airbag in the wet is like riding
a slip and slide, so I’ve been thinking, it’d be nice bring this airbag someplace
else when it’s wet out. To do that, we need to build a portable lip
small and light enough to fit in the back of my Honda, with the airbag. That sounds easy enough but this lip can only
be so small and compact. The one we already have on airbag trail is
dug into the ground for stability, and features hardwood planks for weather resistance and
grip. It’s very big, and very heavy. So our portable lip will need a totally different
design. For starters, I want to make this lip a step-up,
which means it’ll be lower than the back side of the lander. I also want to use as tight a radius as I
can get away with to keep the length of the jump down. If you’ve taken 6th grade geometry you know
that a radius is half the diameter of a circle. Our garage quarter pipe has a 6 foot radius,
and it’s only 4 feet tall. On paper, that looks like this. Our backyard airbag jump has a 10.5 foot radius
and it’s almost 6 feet tall. On paper, it would look like this. To make a jump small enough to fit in my pickup
bed, I’m going with a 5 foot tall lip with a 9 foot radius. To draw that I’m using the lines in my driveway
as a grid to line up this sheet of plywood, then using a 9 foot length of string as a
compass. On one of the sides, I marked an arrow showing
the correct angle of the transition so that we can use a level to get it oriented correctly. I want this lip to be 36 inches wide, so I’m
subtracting the thickness of the plywood from that and cutting a bunch of beams to build
the frame out of. Since I’ve never built a lip exactly like
this, don’t follow my blueprint. I fully expect to make changes to this frame,
and maybe even rebuild it someday entirely. But hopefully it’ll be something we can
transport and ride tomorrow. 1/4 inch plywood can bend a fair amount, but
installing it wet helps to prevent cracking, so I’ll spray this down every so often for
the next 30 minutes and then get to bending it. Bending the plywood is always tricky business. So it’s best to do it… slow and methodically. Now that we’ve built our lip, it’s time
for a dry fit. Not quite ideal, but I’ve got an idea. To hold the
lip together we’ll use these latches, which seemed like a good idea in the planning phases,
but in actuality look super jank. With the lip in two pieces, it fits quite
nicely in my bed, with room to spare. And it’s more than light enough for one
person to lift. But then, there’s airbag. As it turns out, Kevin has professional experience
in the dispatch, transport, and inflation, of bouncy castles, which is essentially what
this airbag lander is. This airbag weighs….a lot. it actually arrived on a pallet. But by using the hand truck and blower as
a sort of staircase, one person can load it into a pickup. This whole setup packs into my bed so nicely,
that it’s actually not sketchy at all. In fact, nothing shifted at all during transport. Setting this up in Kevin’s driveway took
actually less time than setting up at my house. At my house we need to get the bag and blower
from the garage to the lip, which is more work than you would think. Here we can unload everything on site. Time to see if these latches are as jank as
they look. Step ups are really fun. You can easily see the landing on approach,
which is useful. And jumping a step up is very smooth since
you catch the landing at a higher point in your trajectory. Despite a few adjustments and a small learning
curve, we were getting really comfortable on this lip…maybe a little too comfortable. So it turns out that Dave can backflip. And that meant the session had officially
popped off. That was my first backflip attempt outside
of Highland Training Center, and I rotated way too slow. Looks like my flips need some calibration. With under an hour of daylight left, we were
trying to get in as many runs as we could, but Paul had never ridden a wooden lip this size, let alone a double. And so, it’s safe to say our portable airbag
launch worked out pretty well, or did it? As we started to gain confidence and ride
harder, it started to get way sketchier. Eventually we weighed down the center with
a big rock and that solved the problem, but I’ll need to take this ramp apart and redesign
it eventually. A redesign would include a harder angle on
the rear supports to keep the ramp from tipping, and a carriage bolt and wing nut solution
for holding it all together. We’ll do that another day, but I think it
is safe to say that the concept works. Anyone with a pickup of any kind can transport
this huge instant jump anywhere. I hope you enjoyed this build and should you
decide to build one of your own I’d urge you not to follow my blueprint save for maybe
the radius part. I’m really stoked on finally doing a big
backflip, and taking a 360 on something this big as well. It’s amazing how much you can progress when
you have a huge cushion to land on. Thanks for riding with me today and I’ll
see you next time.

100 thoughts on “Building a huge portable bike jump that fits in my Honda”

  1. Not everyone deserves to buy themselves a gift, but you probably do. https://cognativemtb.com/collections/seths-bike-hacks-collection Trail marker kits, sticker packs, hoodies, and teeshirts now available from my official merch supplier, Cognative MTB!

  2. hey Seth my friends and I built our own MTB trails so if you ever want to ride DJ Max trails let me know Please comment back (D-Drew J- Jonah M-max) P.S my channel is Jonah Haughee (Hoy)

  3. My modular kicker ramp didn’t survive the first jump at full height ? Just like Seth, I had to come up with a better way to secure the halves. That is a sweet looking lip???

  4. Hey man. This video rocked. Great build giving me some awesome inspiration. Also some of the editing (dual seths) was a nice touch too. Love your efforts mate.

  5. I just love how you guys are equally thrilled/happy for you landing a backflip as you are for paul landing that jump at all even though it's almost normal for some of the others in your group.

  6. Another video with Paul the Punter sneaking in! This guy is in everything these days. I had to watch a safety video for work the other day. Sure enough there is Paul riding around in the background. Classic f+ckin Paul!

  7. We need a vid at some point of you just riding every trail in the peak. Maybe just live stream a go pro cam for a few hours?

  8. Seth, what about using something like flat washers with your screws to lock the plywood down? Until you get it locked in that is. So the screws don’t tear through. Maybe a faster way.

  9. Really enjoyed seeing a little math Seth. It would be interesting to see a series on the complexities of trail building. (the tech tech side of things)

  10. Seth you should get a roof rack for your Ridgeline. You could put your bike and other stuff on it when carrying your homemade jump. Just a suggestion.
    Thanks

  11. @Seth's Bike Hacks is turning into PastranaLand! Wow sooo much jank but it's insain to see your progression and the "crew" you're building. I think you're "the guy" to know as far as bike youtubers go.

  12. Good woodworking tip on sheet goods. Get a 4×8 piece of blue insulation foam and throw your plywood on top of that (on the ground) .. set your depth and run your cut. You won’t have to worry about hitting anything… and a simple frame will let your use your saw horses with out the worry of cutting through them

  13. I just a Mtb hardtail today because it my birthday day. Any tips to get better? My goal to to ride at summit during the summer.

  14. Seth, you have encouraged me so much over the past few months that I've been able to jump my bike now thanks a lot for your help!

  15. Leash the dogs damn. How annoying, they sniped the camera. And some dogs like to get too close to bicycles. there could be an accident. Only Drama is worthy of being on the side of the trail.

  16. 1st) Cut a number small holes in the jump's plywood face, maybe half an inch square (think side walk tree grating). This will still be strong enough to support hard riding on the jump but will dramatically reduce it's weight.

    2nd) Consider making the plywood a dozen small sections rather than two solid pieces. It's not quite as buttery smooth but it still makes a great take off. This allows you to separate the jump face from the jump frame for transportation purposes. You then latch the jump surface to the jump frame for secure setup.

    3rd) Consider adding a small handful of large leg levelers to the bottom. This will allow you to alter the launch angle a bit for more applications.

  17. I would of never though when i started watching this channel seth would start doing back flips! Anything is possible .

  18. You should check out some of Sam pilgrims videos I assume he has a sponsor through a company that builds portable ramps and they look epic and he's getting like major boost off these jobs like backpack jumps being put together like Lincoln Logs

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