Wheels Evolve Into Balls with Spherical Drive System

Spherical Drive System electric motorcycle being constructed by students at San Jose State University

Spherical Drive System electric motorcycle being constructed by students at San Jose State University

Other than a few variants on tracks or some future designs that fly, motorcycles all have wheels and we know what wheels look like, some sort of disc rotating either forward of backward, right? Well, maybe not, because this group of students from Charles W. Davidson College of Engineering at San Jose State University looked at a few sci-fi vehicles and thought, "Hey, why not balls?" Why not, indeed? They've designed and begun building a senior project to demonstrate the feasibility of something most of us would not even consider.

Rendering of spherical drive electric motorcycle

Rendering of spherical drive electric motorcycle

The spherical wheels are constructed of carbon fiber and fiberglass with an industrial rubber coating and are friction driven by three electric motors mounted slightly off center on top of the ball. Because of the three motor arrangement, the balls can rotate or spin in any direction which makes for a rather unstable platform on which to base a motorcycle, but the students plan to address this issue with a computer control system using a gyro-accelerometer combination to determine the necessary movements needed to maintain balance and move in the proper direction.

As a senior project, this is extremely interesting and makes a fine showcase for the students' abilities, but as a practical matter, it seems they will have to overcome a great many problems which, in the end, may lead to a motorcycle with no real advantage over conventional wheels.

I'll be very interested in seeing the end result of their work and I give them very high marks for out of the box thinking.

Thanks for the tip, Mark!

Link: Spherical Drive System
Link: Spherical Drive System on Facebook

Spherical Drive System electric motorcycle frame

Spherical Drive System electric motorcycle frame


  1. JP says

    Friction drive has a tendency to become no drive when the right (or wrong as the case may be) substance gets on the drive or driven surface.

  2. Jack says

    I recently saw a picture of a tombstone that stated, “You will have an eternity to think inside the box.”

    Good luck and keep learning by doing

  3. fharmon says

    Welll… my personal opinion is that they didnt think this through. Perhaps as an excersize it surves some purpose, why not a ball-wheel unicycle to apply the computer servo’s action to, or a paddle wheel unicycle for water, I dont know much but I know that even slight surface variations make a motorcycle feel odd, this thing will never be a predictable ride at any speed. Just saying. That said, I will follow it to its conclusion. Please keep up with the post. B.t.w; Gunbus ever get ridden?

  4. says

    Those “handle bars” are mostly for holding on and making “suggestions” to the computer. No need for direct steering input (or feedback) with computer driven 360 degree directional capability at each end.

  5. says

    I did a lot of researching and sketching some ideas years ago into building a ball wheel driven “motorcycle.” No actual construction though. I kept coming to the conclusion it would be a neat parlor trick but not much else. I really hope they prove that’s not the case. I love the idea of it.

  6. FREEMAN says

    I’m surprised nobody’s said it already. This system concept was in the movie I, Robot. The director talks about it briefly.

  7. Josh says

    There isn’t nearly enough friction with the water to make it work – the slef balancing would fail instantly. it might float, but up side down. And without friction, it can’t propel itself either. But yes, it could come with a sticker “in case of emergency, motorcycle may be used as a floatation device” ๐Ÿ˜€

      • Paulinator says

        Those are big balls. Put the heavy battery packs and drives inside them (down low), then put lugs and chris-crossed load-bearing tracks (grooves) on the outside of them. Use RF telemetry to control the wheels.

        Like others, I don’t really see any marketability here…but itโ€™s an interesting exercise I suppose.

        • George says

          Moving the batteries, controls and electronics inside each ball would certainly be an improvement. It would lower the center of gravity and eliminate the hazard of road materials interfering with drive mechanism.

          The real challenge comes in moving away from friction drive for real performance and efficiency and integrating a gyroscopic speed-based steering and balancing system (basically, lean to turn).

  8. Adriaan says

    The old French front wheel drive Solex mopeds used to have friction drive, and even the puny power from that little engine would slip when wet..

  9. bkowal says

    I think this is an excellent student design project. Of course it will have no practical application but what the students will learn about control systems will be hard to come by any other way.
    Too often we see interesting projects on The Kneeslider, but many chime in immediately that they wonโ€™t work, and most are probably correct. Experience tell us this. These kids have a great way of getting this experience.

  10. B50 Jim says

    Probably won’t work. Completely impractical. But that’s not the point. College is a safe place for young (and not-so-young) people to learn new ways to apply technology and knowledge that will lead to projects that will work and will be practical. But who knows? As Orville said to Wilbur, “this thing might work!” They were bicycle mechanics, and look what they did.

    Also, consider this: A motorcycle is basically a sphere with the greater parts lopped off and an axle stuck through the middle, so actual spheres aren’t so crazy.

    • todd says

      it’s that axle stuck through the middle that allows physics to accomplish the same thing that a computer will attempt to replicate. Is this an example of technology for technology’s sake? Regardless, it’s a great learning tool, hopefully it will teach them that simplicity and analog control is better.


      • Sid says

        simplicity in design has its place, but some times progress includes complexities to achieve a final, simple execution.

        Case in point: consider everything that went into making your analog comment on the world wide web possible.

        [And, progress also involves more than small displacement motorcycles with less than 100 hp]

        • B50 Jim says

          Look at military technology — which is about 10 years ahead of commercial applications. The Stealth bomber would plummet like a stone without computer controls. A human pilot is incapable of flying it with just his own, slow reflexes. I’m not sure that’s a good thing, but it demonstrates the power of digital controls. For “old guys” like me it’s incredible. My Toyota pickup has more computer power than the software that helped put a man on the Moon. It learns how I drive and adjusts the engine accordingly for maximum efficiency; when I drove from Chicago to Baxter Cycle in Marne, Iowa, to pick up my ’71 BSA Thunderbolt, the truck had all kinds of trouble with the glacial hills in the western part of the state until it finally figured out how best to deal with the inclines. That boggles me.

  11. Roger says

    Given the right kind of control algorithms and reliable drive mechanism, there is potential here for some interesting results. Thrust vectoring?

    We have a tendency to look at prototypes and scoff at them. Many “failures” become essential pieces of our social fabric later on, after the technology catches up with the idea.

    As for solutions waiting for problems, it’s in good company.

  12. Talon says

    Well it looks interesting… It’ll be a good learning experience for the students. I’m actually interested to see it finished. But here’s my 2 criticisms.
    I don’t think that those motors would be effective at slowing the bike once it has some speed behind it. I guess you’ll just have to use your feet on the balls to stop :P.
    No wheelies! and you couldn’t even take it off of any sweet jumps. However anybody should be able to drift that thing as soon as they get on it right?

  13. Jaysin says

    Good for them. No need to shoot down any new ideas. Besides, initial / concept / project build doesn’t always mean finished project.
    once they get they gyro control down and enough data or experience to work with, I could see them with some sort of computer controlled magnet driven system, and your bike if the future. Shoot, the batpod lions ridiculous at first glance to most riders, but it really rides once they got the hang of it. Just not as a traditional motorcycle.

  14. mustridemore says

    I don’t see it making any sense for a bike, but put them on a car, and parallel parking becomes so easy that a woman could do it.LOL.

  15. mustridemore says

    How about losing the friction drive and using the wheels/balls as a “armature/rotor” of infinite directional motor. I am picturing lining the ball with a soccer ball type pattern of magnetic materiel (I know it would be heavy), then using electromagnets to control the rotation.Just a thought.

    • says

      When I gift first looked at this, Iassumed it would be driven in shine way via electrons. I’d thought about spheroid wheels in the past as a solution to gaining an infinitely contactable surface that ismore stable at low/no speed. The conclusion I’ve come to so far is that it works better with two large half- sphere wheels hubbed centrally.

  16. says

    it will be very interesting to ride as the rolling edge will decrease in diameter as you bank into a corner,and i imagine it will be very hard to pull it out of being banked over as you exit said corner!