FURY | For Legal Reasons, This Isn't A Motorcycle

SALUTATIONS, MOTHERFUCKERS

hello-there-well
i’m back

Why am I building a new bikeboard?

(the reasons)

Orbital has a lot going for it, but you know what else it’s got? Teething problems. (gimme a break, there’s no design handbook for these things) Here’s the big ones and how to fix them:

  • Insufficient lean angle while cornering → raised deck, wider wheels
  • Insufficient steering input before ankle tipover → lower deck, wider wheels, positive steering control
  • Hella turn radius → positive steering control
  • Chain derailment (got worse over time and it’s a big yikes :grimacing:)–> high rigidity rear triangle, direct load path for chain tension, thicc chain

What do all these have in common? They require hacking apart significant sections of the chassis and fabricating new parts to graft on in their place. At that point, might as well build a new chassis. But wait! All the drive components are tightly integrated into the existing chassis, so reusing them would greatly limit the design freedom for the new version.

Rationalization complete! Time for a new board! Let me just crack open the old bank account and -
house-explosion

Don’t worry, I’ve got backup.

  • 2x SKP dual solos! (Only one of which I bought!)
  • 4x Reacher motors, also bought from the forums 2nd most famous duck @Skyart !
  • Rare Davega from @janpom !
  • Metr Pro from @rpasichnyk !
  • Plus some other key components that I got on the cheap by being real patient and trapping them inside a cardboard box with a stick propping it up and a pile of wingnuts inside as bait

Many thanks to all the vendors who donated to the BOTY prize pool, the gadgets are really going to give this build the hi-tech finish it deserves. And a special thanks to @Skyart , who was way more generous than he had to be for no discernible reason, and really upped the level of batshit crazy performance I was able to afford for this project.

I’m also parting out Orbital! Check it out if you want a big motor or a big battery.

Aside from bug fixes, how will Fury differ from Orbital?

(the reasons)

The design of Orbital was intentionally conservative, mechanically speaking. I was trying out several new techniques for the first time (like forged carbon and 3D fixturing), so I kept the design down to the bare essentials.

This time around, the kid gloves are off.

Fury will use an integrated chassis, with the deck lid completing the torsion box:
FuryExplodedChassis_1

The deck lid will carry a carbon fiber torsion bar steering mechanism, as a ripstick homage, to improve responsiveness:
FuryExplodedDeck_1

Articulation points for the steering mechanism and suspension linkages will be forged from carbon and fused into the panel structure:
FuryExplodedSteering_1

Four motors will feed power to a single moto chain sprocket through a laser cut/3DP gearbox, because we need to push the frontiers of Esk8 audio pr0n:
FuryExplodedDrive_2

And because speed is a bikeboard’s natural habitat, this machine will be able to merge onto the goddamn highway.

Also, I reached out to NY DOT to see if this thing could be registered as a scooter or motorcycle, and the goddamn luddites told me to jag off.


Anyway,

Obligatory spec list:


Fury vs. Orbital thrust curves, with standing/tucked drag curves as reference

CONFIGURATION

  • 18s9p P42A battery, dual SKP solo, quadruple Reacher 6385 245Kv
  • Gearing 23/60 (gear stage), 10/42 (chain stage), 11:1 total
  • Wheelbase 1600mm, ride height 225mm, lean clearance 55deg, rake 25deg, trail 100mm
  • Suspension travel 100mm front, 75mm rear
  • Michelin dual compound tubeless tires
  • Hydraulic moto brakes

PERFORMANCE

  • 1.0kN thrust up to 75kph
  • 120kph redline speed (burst)
  • 75kph cruise speed (continuous)
  • 90km range (estimated)


FURY (n.) - A species of dragon known known for its overwhelming speed

26 Likes

9 Likes

Any bikeboard design starts with the wheels IMO, so the engineering can start after these are set up for measurements. As recieved, they’re mechanically fine, but cosmetically…down in the dumps.

A few hours with paint stripper and a wire wheel sorted out the chips, and a clear coat finishes it off.

Rust remover and scotchbrite for all the steel bits, and the interior region of the brake rotors gets the same trim scheme as the rims.

Assembled and aired up! Now the real work can begin.

10 Likes

Videos are back by popular demand! They won’t be a chronological build log (too much work to make that kind of series, I’ll just post pictures), but instead focus on the information and fabrication techniques that make a project like this possible. Hopefully this generalized style is more helpful to people looking to apply new skills to their own projects.

This one is about the design considerations for the general layout of bikeboards, using both kinds of CAD as an illustration tool:

Here’s a standalone copy of the linkage geometry charts so you can scroll through with the video slider:

2 Likes

PART ONE: I Vacuum Bagged The Whole Damn Thing 'Cuz I’m Chassis That Way

Carbon forgings are coming along slowly and steadily.
Here’s one fresh out of the mold, still with its dusting of 13 original herbs and spices:

And after much cleanup and grinding:

These flat panels are made by drawing patterns onto craft paper and vacuum bagging them onto end grain balsa, to make a lightweight sandwich that’s carvable with a knife:

All the panels are glued up with thickened epoxy to make the center frame of the chassis, and the outside edges are rounded over:

The inside edges are filleted with a epoxy/silica/sawdust mix:

The forgings are glued on and over-wrapped with carbon:

The tricky spots are wrapped with flax fabric manually:

The whole thing gets bagged up (and i make my room extremely messy):

The end result is approved by my supurrrvisor:

19 Likes

That’s where the project has stood for the past month or so. My work schedule should start easing up a bit, hopefully.

The chassis core needs a couple bits trimmed off, a couple cosmetic details added on, but it’s pretty much there. Next up is the deck plate and battery.

11 Likes

Always impressive dude!!! Can’t wait to see the rest!

10 Likes

Amazing project again bro.
Keen to follow the journey as it continues!

5 Likes

Always stoked to see a new build thread from you! Watching for sure :heart:

6 Likes

It wasn’t approved. It was stolen. You have to make a new one now because that one belongs to the cat :rofl:

For the law issue, I’d check all the laws myself because state employees don’t always know them correctly. I had an issue before but after showing/ giving the law codes proving I was legally in the right it went away. There could also be local ordinances that allow you to use it or ban them so I’d check those too

2 Likes

furry?!!

1 Like

This is straight up FIRE :fire:

5 Likes

Damn another flyboy build can’t wait for the sick ass flybys :laughing:

5 Likes

Finish off my catmobile hooman

2 Likes

Thanks for the kind words everyone!

Correct, he sleeps in it now, it don’t belong to me no more.
20231217_162917_1

That’s a good idea, maybe I’ll try just sending in the application directly in order to force the issue as well.

Yes, my supervisor is a furry. His suit is very small, and he’s very committed to the bit.

y7Z0L

I know, I can feel his judgment from across the room.

6 Likes

Trying to understand the mechanics of the front suspension/steering & my head hurts, kind of like this? Maybe I need to read your last build thread again




2 Likes

The steering will work the same as orbital, the geometry has had some minor tweaks to improve the steering response at low speed.

20220515_084154_11

The thing that creates the most visual clutter is that the connecting arms will now have suspension in them. I think those bikes you posted have swingarm suspension on the front, with a pivot at the front of the arm. Kind of like a mountain bike linkage fork, right?

1 Like

Yeah they are a mix of unusual fork designs hun centre steered, this is something very different.

Trying to imagine the feel & skill required to even get going. Orbital was really awesome :saluting_face:

2 Likes

Thanks!
That part did take a lot of practice, but it didn’t have anything to do with the steering mechanism. It would have been the same if it had a regular steerer tube.

2 Likes

Very cool, looking forward to seeing the end result.

What is the benefit of doing the steering arms like speedboard vs caster style like 2swift?

2 Likes