# Is this hoverbike design feasible? - Inventor builds hoverbike **URL:** \ **Category:** In My Humble Opinion\ **Created:** [June 11, 2011, 3:44am UTC](https://boards.straightdope.com/t/is-this-hoverbike-design-feasible-inventor-builds-hoverbike/585071 "2011-06-11T03:44:29Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![astro](https://avatars.discourse-cdn.com/v4/letter/a/9dc877/32.png) [@astro](https://boards.straightdope.com/u/astro)\ **Post date:** [June 11, 2011, 3:44am UTC](https://boards.straightdope.com/t/is-this-hoverbike-design-feasible-inventor-builds-hoverbike/585071/1 "2011-06-11T03:44:29Z")
[Is this potentially for real?](http://www.gizmag.com/hoverbike/18813/) Does a 1100 cc motorcycle engine really have enough power/weight to fly a hoverbike? > [@](#): > > Adventurous motorcyclists might be familiar with the thrill of getting airborne at the top of a rise, but the Hoverbike is set to take catching some air to a whole new level. With a 1170 cc 4-stroke engine delivering 80 kW driving two ducted propellers, the inventor of the Hoverbike, Chris Malloy, says with its high thrust to weight ratio, the Hoverbike should be able to reach an estimated height of more than 10,000 feet and reach an indicated airspeed of 150 knots (278 km/h or 173 mph). At the moment these are only theoretical figures as the Hoverbike hasn’t been put through its paces yet, but Malloy has constructed a prototype Hoverbike and plans to conduct real world flight tests in a couple of months. ---
**Author:** ![Arrendajo](https://avatars.discourse-cdn.com/v4/letter/a/e0b2c6/32.png) [@Arrendajo](https://boards.straightdope.com/u/Arrendajo)\ **Post date:** [June 11, 2011, 5:29am UTC](https://boards.straightdope.com/t/is-this-hoverbike-design-feasible-inventor-builds-hoverbike/585071/2 "2011-06-11T05:29:14Z")
I’m not an engineer, but I do ride a scooter! Yes, I would think it’s powerful enough, but hoo what a dangerous ride! ---
**Author:** ![Rhythmdvl](https://avatars.discourse-cdn.com/v4/letter/r/85f322/32.png) [@Rhythmdvl](https://boards.straightdope.com/u/Rhythmdvl)\ **Post date:** [June 11, 2011, 5:35am UTC](https://boards.straightdope.com/t/is-this-hoverbike-design-feasible-inventor-builds-hoverbike/585071/3 "2011-06-11T05:35:44Z")
Of course not. It’s just Ned in the closet with paper and a comb. ---
**Author:** ![GuanoLad](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/guanolad/32/42_2.png) [@GuanoLad](https://boards.straightdope.com/u/GuanoLad)\ **Post date:** [June 11, 2011, 5:41am UTC](https://boards.straightdope.com/t/is-this-hoverbike-design-feasible-inventor-builds-hoverbike/585071/4 "2011-06-11T05:41:31Z")
I can see what makes it hover, but I can’t see what makes it go forward, or what stops it from tipping over. ---
**Author:** ![astro](https://avatars.discourse-cdn.com/v4/letter/a/9dc877/32.png) [@astro](https://boards.straightdope.com/u/astro)\ **Post date:** [June 11, 2011, 5:49am UTC](https://boards.straightdope.com/t/is-this-hoverbike-design-feasible-inventor-builds-hoverbike/585071/5 "2011-06-11T05:49:36Z")
> [@GuanoLad](#): > > or what stops it from tipping over. That would be the bungee cords tethering it to the ground. It does look like it might flip if you as much as looked at it wrong. ---
**Author:** ![TriPolar](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/tripolar/32/3008_2.png) [@TriPolar](https://boards.straightdope.com/u/TriPolar)\ **Post date:** [June 11, 2011, 6:26am UTC](https://boards.straightdope.com/t/is-this-hoverbike-design-feasible-inventor-builds-hoverbike/585071/6 "2011-06-11T06:26:47Z")
It is quite feasible. Several designs like this have been attempted over time. The Hiller Flying Platform was a single rotor version of this made in the 50’s (actually a two counter-rotating rotors on a single shaft). It should be extremely stable. It is essentially a small tandem helicopter. It is likely to be slow, noisy, and cost more than predicted. ---
**Author:** ![Johnny\_L.A](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/johnny_l.a/32/1084_2.png) [@Johnny\_L.A](https://boards.straightdope.com/u/Johnny_L.A)\ **Post date:** [June 11, 2011, 6:43am UTC](https://boards.straightdope.com/t/is-this-hoverbike-design-feasible-inventor-builds-hoverbike/585071/7 "2011-06-11T06:43:33Z")
> [@TriPolar](#): > > It is essentially a small tandem helicopter. Helicopters are inherently unstable. Also, the hoverbike has fixed-pitch impellers. Helicopter rotors are much more complex. I don’t want to get into it right now, but suffice it to say that a fully-articulated rotor has hinges for feathering, flapping, and lead-lag. (Semi-rigid rotor systems – two blades – don’t need lead-lag hinges.) ---
**Author:** ![Bosda\_Di\_Chi\_of\_Tricor](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/bosda_di_chi_of_tricor/32/16845_2.png) [@Bosda\_Di\_Chi\_of\_Tricor](https://boards.straightdope.com/u/Bosda_Di_Chi_of_Tricor)\ **Post date:** [June 11, 2011, 8:48am UTC](https://boards.straightdope.com/t/is-this-hoverbike-design-feasible-inventor-builds-hoverbike/585071/8 "2011-06-11T08:48:17Z")
> [@Rhythmdvl](#): > > Of course not. It’s just Ned in the closet with paper and a comb. 😕😕😕WTF?!😕😕😕 ---
**Author:** ![msmith537](https://avatars.discourse-cdn.com/v4/letter/m/d9b06d/32.png) [@msmith537](https://boards.straightdope.com/u/msmith537)\ **Post date:** [June 11, 2011, 1:28pm UTC](https://boards.straightdope.com/t/is-this-hoverbike-design-feasible-inventor-builds-hoverbike/585071/9 "2011-06-11T13:28:30Z")
[I forsee this ending something like this.](http://www.youtube.com/watch?v=goYs047SoGE&feature=related) > [@Bosda\_Di\_Chi\_of\_Tricor](#): > > 😕😕😕WTF?!😕😕😕 I think it’s a Simpson’s reference. ---
**Author:** ![Rand\_Rover](https://avatars.discourse-cdn.com/v4/letter/r/db5fbb/32.png) [@Rand\_Rover](https://boards.straightdope.com/u/Rand_Rover)\ **Post date:** [June 11, 2011, 2:39pm UTC](https://boards.straightdope.com/t/is-this-hoverbike-design-feasible-inventor-builds-hoverbike/585071/10 "2011-06-11T14:39:11Z")
You know, I’m sure people scoffed at the Wright Brothers . . . but that ain’t stopping me from scoffing at this guy. Scoff scoff scoff. I wish there was a way I could short the idea. I’m certainly no aeronautics expert, but I’ve flown small planes and have been interested in all manner of flying gizmos for years, and I just don’t see how this thing could possibly work in safe manner. Seems like it would at least need adjustable pitch rotors and a gyro-guided system that keeps the rotors horizontal. ---
**Author:** ![Czarcasm](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/czarcasm/32/4050_2.png) [@Czarcasm](https://boards.straightdope.com/u/Czarcasm)\ **Post date:** [June 11, 2011, 3:07pm UTC](https://boards.straightdope.com/t/is-this-hoverbike-design-feasible-inventor-builds-hoverbike/585071/11 "2011-06-11T15:07:38Z")
> [@astro](#): > > That would be the bungee cords tethering it to the ground. It does look like it might flip if you as much as looked at it wrong. It could also be four metal legs with bungee cloth wrapped around them. ---
**Author:** ![TriPolar](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/tripolar/32/3008_2.png) [@TriPolar](https://boards.straightdope.com/u/TriPolar)\ **Post date:** [June 11, 2011, 3:15pm UTC](https://boards.straightdope.com/t/is-this-hoverbike-design-feasible-inventor-builds-hoverbike/585071/12 "2011-06-11T15:15:39Z")
> [@Johnny\_L.A](#): > > Helicopters are inherently unstable. Also, the hoverbike has fixed-pitch impellers. Helicopter rotors are much more complex. I don’t want to get into it right now, but suffice it to say that a fully-articulated rotor has hinges for feathering, flapping, and lead-lag. (Semi-rigid rotor systems – two blades – don’t need lead-lag hinges.) I didn’t know what kind of rotor system it had, but that doesn’t matter. Helicopters with counter-rotating rotors are extremely stable, even with fixed pitch. ---
**Author:** ![J-P\_L](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/j-p_l/32/3156_2.png) [@J-P\_L](https://boards.straightdope.com/u/J-P_L)\ **Post date:** [June 11, 2011, 7:58pm UTC](https://boards.straightdope.com/t/is-this-hoverbike-design-feasible-inventor-builds-hoverbike/585071/13 "2011-06-11T19:58:57Z")
> [@TriPolar](#): > > I didn’t know what kind of rotor system it had, but that doesn’t matter. Helicopters with counter-rotating rotors are extremely stable, even with fixed pitch. Helicopters have the rotor on top and all the weight ( or centre of gravity ) is hanging below which makes it reasonably stable. With that hoverbike, the rider is most likely sitting above the CG, not a good idea. ---
**Author:** ![Czarcasm](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/czarcasm/32/4050_2.png) [@Czarcasm](https://boards.straightdope.com/u/Czarcasm)\ **Post date:** [June 11, 2011, 8:05pm UTC](https://boards.straightdope.com/t/is-this-hoverbike-design-feasible-inventor-builds-hoverbike/585071/14 "2011-06-11T20:05:44Z")
Are there any videos of it taking off from the ground? So far, I’ve only seen a still photograph and a short film of it already “flying” supposedly. As I stated before, the still photo could have legs mocked up to look like taut bungee cords. In the video the right side of the craft is hidden from view, and could be supported on that side. ---
**Author:** ![astro](https://avatars.discourse-cdn.com/v4/letter/a/9dc877/32.png) [@astro](https://boards.straightdope.com/u/astro)\ **Post date:** [June 11, 2011, 8:30pm UTC](https://boards.straightdope.com/t/is-this-hoverbike-design-feasible-inventor-builds-hoverbike/585071/15 "2011-06-11T20:30:01Z")
> [@Czarcasm](#): > > Are there any videos of it taking off from the ground? So far, I’ve only seen a still photograph and a short film of it already “flying” supposedly. As I stated before, the still photo could have legs mocked up to look like taut bungee cords. In the video the right side of the craft is hidden from view, and could be supported on that side. They kind of look like more like bungee cords vs legs, plus there is the video of the fans working. I don’t see it as a great engineering accomplishment to have those two fans levitate the very spartan frame connecting them a foot or two off the ground. So far that’s all that’s been done. ---
**Author:** ![johnpost](https://avatars.discourse-cdn.com/v4/letter/j/f17d59/32.png) [@johnpost](https://boards.straightdope.com/u/johnpost)\ **Post date:** [June 11, 2011, 8:49pm UTC](https://boards.straightdope.com/t/is-this-hoverbike-design-feasible-inventor-builds-hoverbike/585071/16 "2011-06-11T20:49:50Z")
> [@Rhythmdvl](#): > > Of course not. It’s just Ned in the closet with paper and a comb. > [@Bosda\_Di\_Chi\_of\_Tricor](#): > > 😕😕😕WTF?!😕😕😕 > [@msmith537](#): > > I think it’s a Simpson’s reference. Sorry, kids! There’s the no such thing as hoverbikes! They’re just a couple of huffies on a fishing line! The Joy of Sect 5F23 08-Feb-1998 best episode ever. ---
**Author:** ![TriPolar](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/tripolar/32/3008_2.png) [@TriPolar](https://boards.straightdope.com/u/TriPolar)\ **Post date:** [June 11, 2011, 10:00pm UTC](https://boards.straightdope.com/t/is-this-hoverbike-design-feasible-inventor-builds-hoverbike/585071/17 "2011-06-11T22:00:32Z")
> [@J-P\_L](#): > > Helicopters have the rotor on top and all the weight ( or centre of gravity ) is hanging below which makes it reasonably stable. > > With that hoverbike, the rider is most likely sitting above the CG, not a good idea. That’s an oversimplification of something much more complicated, and basically irrelevant. A single-screw helicopter has a lot of imbalanced forces at work. With counter-rotating wings the forces can be balanced, and the rotorcraft will maintain attitude. Look at the [Hiller Flying Platform](http://en.wikipedia.org/wiki/Hiller_VZ-1_Pawnee). The pilot is standing on top of the rotor. ---
**Author:** ![PlainJain](https://avatars.discourse-cdn.com/v4/letter/p/5daacb/32.png) [@PlainJain](https://boards.straightdope.com/u/PlainJain)\ **Post date:** [June 11, 2011, 10:20pm UTC](https://boards.straightdope.com/t/is-this-hoverbike-design-feasible-inventor-builds-hoverbike/585071/18 "2011-06-11T22:20:04Z")
I trust [this photo](http://www.gizmag.com/hoverbike/18813/picture/135535/) is real, but that doesn’t mean it can do anything resembling flight. A lot people have a bad notion of what will and what won’t work in practice. Graphic link: [Franz Reichelt](http://www.youtube.com/watch?v=BepyTSzueno) ---
**Author:** ![GuanoLad](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/guanolad/32/42_2.png) [@GuanoLad](https://boards.straightdope.com/u/GuanoLad)\ **Post date:** [June 12, 2011, 4:45am UTC](https://boards.straightdope.com/t/is-this-hoverbike-design-feasible-inventor-builds-hoverbike/585071/19 "2011-06-12T04:45:05Z")
Could the bike stay upright if it had counterbalances to create a lower centre of gravity, like a tightrope walker’s pole, or [the forks and cork trick](http://www.dynamicscience.com.au/tester/solutions/flight/strucuturesandforces/balancedstr1.htm)? Or does it need a physical fulcrum point for that to work? ---
**Author:** ![TriPolar](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/tripolar/32/3008_2.png) [@TriPolar](https://boards.straightdope.com/u/TriPolar)\ **Post date:** [June 12, 2011, 4:24pm UTC](https://boards.straightdope.com/t/is-this-hoverbike-design-feasible-inventor-builds-hoverbike/585071/20 "2011-06-12T16:24:54Z")
> [@GuanoLad](#): > > Could the bike stay upright if it had counterbalances to create a lower centre of gravity, like a tightrope walker’s pole, or [the forks and cork trick](http://www.dynamicscience.com.au/tester/solutions/flight/strucuturesandforces/balancedstr1.htm)? Or does it need a physical fulcrum point for that to work? That is unnecessary. Look at the link I posted a couple of posts back. The Hiller Flying Platform was impractical for a variety of reasons, one of which, it was so stable it was difficult to make it move horizonatally. That required tilting the platform, and it would tend to right itself again, because it is stable. Did you ever ride a bike? Where was the center of gravity? It wasn’t below the wheels. [Next page](https://boards.straightdope.com/t/is-this-hoverbike-design-feasible-inventor-builds-hoverbike/585071.md?page=2)