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Designing a Hubless Bicycle. From Rhino to SolidWorks – Your Input?

by Josh on January 19, 2009 · View Comments

waugh-bicycle-tnThis bicycle concept has been on the web… A LOT. You may have seen it, but you may not know that it was designed using 3D. Yes, I know, it’s almost obvious. The design is also being refined in SolidWorks and that’s where you come in.

Brad Waugh has a cool idea. A hubless bike. It challenges the ideas of motion and all that nonsense of how things should actually rotate. The form is excellent, but how can he make it functional? Maybe more pratical?

Here’s the concept rendering and a bit more from Brad.

I used Rhino to build and Flamingo to render on the original. The new version is being modeled in Solidworks and will be rendered in Vray. -Brad Waugh

The form is great, in my opinion. So what does Brad need to consider as he approaches the redesign in SolidWorks?

waugh-bicycle-01
waugh-bicycle-02
waugh-bicycle-03
waugh-bicycle-04

Brad on Behance

Tagged as: bicycle, Design Process, Product Design, Rhino

  • Tulsabiker
    Off topic, but the cantilever seat arm reminds me of the Sh*tbike segment in Bike Magazine.
  • elvin
    you could use carbon fiber as substitute to all metallic and plastic parts especially on the wheels Ü
  • Robert N.
    I designed a hubless bicycle almost 15 years ago and I went through the process of making it functional. Why would I want to tell Brad how to make his work?
  • Hi Robert. For nothing else than to have some community involvement in a design. The open idea of designing a product isn't to diminish the work other people have put into designs, but to learn from everyone who's been through the process to make it better. I also like putting up these post every once in a while to spur on interest in designs that seem impossible.
  • Eric
    I have a working hubless (rear) bicycle. Although mine isn't designed to be very lightweight (it was more form than function driven), it does work pretty well. After having built one, I can agree with the old addage (don't try to reinvent the wheel). ... well.. it does look cool anyway
  • Leon van Rensburg
    As Engineer and cyclist, I found the concept of the mono cycle quite intriguing. That's where my curiosity of the support / bearing system came from, which led me here. These designs are as old as the hills, but seem to have some important cues such as a spoked outer rim and basic open guide wheel support. It might just work with a bit of modern input.

    http://velospace.org/node/3823
    http://www.dself.dsl.pipex.com/MUSEUM/TRANSPORT...
  • Justin
    so i am a bit late on reading this. the 'hubless' monster is not hubless. i did a similar concept back in uni for an electric motorbike. its just a large bearing (with as few as 3 conract points), just so happens the hole in the centre is a bit bigger than usual. this way everything is shielded from debris.
  • KMaren
  • bigmikeo
    Quick search found this also

    http://www.youtube.com/watch?v=yJPTSaARlvs
  • MAN. great find. The video is the most impressive., Love the way it looks like the wheels are just floating on the surface.

    Here's another one on YouTube that is similar to the 'channel/partial hub' idea I was talking - http://www.youtube.com/watch?v=VwHyaiIEgPs
  • bigmikeo
    This just came into my inbox.....

    http://www.amenmotorcycles.com/Images/Gallery-H...

    Granted it uses fiction drive. Still cool.
  • Steve McGrath
    I'm not an engineer, but I ride a lot. That said, ditto on doubts about how such wheels could be strong enough to hold up, and anyone who bougth a bike like that would want the wheels to be stiff enough to REALLY transfer power. The crankarms look too thin as well -- another place where stiffness matters. Another thing: although you're eliminating the friction of a central hub, you're adding friction at those places where the wheels engage with the frame -- in fact, it looks like two "hubs" each. Unless this is a custom one-off for an accomplished rider, you'd need to build in ways to adjust the seat height, fore and aft -- those mechanisms aren't evident. And the handlebars as set up fly in the face of everything we know about aerodynamic biking positions, as well as racers' need to change hand positions with terrain and competitive circumstances.
  • Thanks for the input. I developed and rendered this concept in about 11 weeks. That was about three years ago and it has sat as is ever since.

    I have addressed many of your concerns in the new concept, but in the end it still just that- a concept. If the tech becomes available and someone wants to work with me on producing it, I'm more than willing.

    John A, you have made something strikingly similar to what I have been working on.
  • Dan Quigley
    Brad, What would it take to make a working prototype. I would like to see your latest concept.
  • John_A
    Thanks, I've been a designer and an inventor a long time, and I love challenges like this.

    My first thought looking at it was to mount something external to the rim, like a rail, and use stationary trucks like a roller coaster for the support. Kind of an inverted, inverted roller coaster. Rail moves and the wheels stay still :)

    The first obvious flaw in that is FOD tolerance. The design should incorporate a way to make the rim stronger into the attachment mechanism, or you'll add a lot of extra weight making those separate items. You'll also save a lot of prototype money if you make the tires something standard or close to it. Any external rail beyond the side wall would risk striking the ground in a corner.

    I thought about it a little last night, and I'll do some more mods to my model and post another screen shot. I wanted to add holes to eliminate the need for a wiper. I like your cogged rear wheel, very elegant and solid. In a very unscientific test, my mountain bike has a low gear of just under one to one. High gear should spin the rear wheel at least two times, more like 2.5 to 3. I'd make the gear that the pedals ride on as large as possible to avoid losses in your gear train.

    Just make sure you put front and rear suspension to take the shock out of bumps, or the rims will bend way too easy. I'll give bonus points if you come up with a way that transfers the shock and spreads it out over the two wheels, or dissipates it another way than just having the wheel bounce up. The shock load is normally applied at more of a 60 degree angle, rather than vertical, so something that lets the wheel react back as well as up might be an advantage in this design, at least on the front wheel. Maybe incorporate a spring in tension on the upper frame rail, pulling back on the upper vertical tube the handlebars and front wheel attach to (headset). It would allow the wheel some rearward play. Couple that with a spring in the headset for your up and down and you get a neat package that wouldn't be visible.
  • A striking concept, and I like to see industrial designers *challange* convention, even if convention then smacks the challanger back to their place. I do get the impression that this is a solution in search of a problem. Strength and stiffness are compromised and friction is added- to what end?

    Okay, let's ask: Where is this concept actually used, and what can we learn from the existing implementation?
    A disc-cutter was seen in concept using this idea, may 15 years back. The reason it used a rim-hub was to double it its cutting depth, more or less (it would cut with just less than its diameter, rather than just less than its radius). Ground clearence of 4x4 vehicles is another application, though one already well-served by a different solution (hub is still central, but there is no continous axle across the width of the vehicle).
    Engineers and keen cyclists will be thinking "Nah. Why has he even bothered rendering this idea?". Even if material science advances, these materials will just be used in a more convention manner to create a lighter/stronger bike.
    Perhaps a rethink of the target market is in order? Instead of styling it as a racing bicycle, perhaps it could be sold as a machine to pose around town on, much like those 'chopper' bicycles.
  • George
    Ah the Concept is so neat
    till it's ridden on the Street.
    Ouch the rut that grabs the wheel
    twisting force for for frame to deal
    the last thing I remember is flashing light
    to all farewell not home tonight.
  • LOL :) Sometimes I wish more comments were like this. That frame definitely take a beating.
  • John_A
    Thought I'd put together a quick one to talk about the problems involved:

    http://i238.photobucket.com/albums/ff113/Generi...

    There would need to be four of the "trucks" in this assembly for it to work, two sets on each side of the rim. The four yellow pegs would be attached to the vertical tube where the forks normally attach. I put two rollers on each truck, one riding inside, the other outside, to allow for a rock or other flotsum to enter the rim. If the yellow pin on the truck were made of a spring material, and preloaded, and the truck wheels were soft, it would spin over small objects. You'd definately need a wiper of some type to keep as much stuff out as possible. It could still never venture off road, or off track to be honest. But it would look nice.
    Forgive the crude model but that's all I have time for. I'd probably do some kind of elliptical wheel on the truck and put a little effort into a neater truck if I were working on it. The numerous wheels would add up to a lot of parasitic drag.

    There are numerous problems with this concept, but this is the most direct method of mounting I could come up with quickly. Hubless won't replace a regular hubbed rim anytime soon.
  • WOw John. Thanks. That's great. I think you're on the right track.. seems like those trucks would also need to be spaced far apart from each other to provide stability for the wheel. I like this idea. I'm sure it will give Brad some ideas about the mechanism. THanks!
  • Incredible concept! However, I believe it will remain that way until some much more advanced materials and bearings are developed.
  • TX80
    interesting concept, but too many unresolved variables and also laws of physics being defied.
  • Glad to know I'm not the only one that though:
    How the **** is that gonna work?
    But great renders anyway.
    And a cool idea make some more of these and bake them all into on cool working concept.
  • KMaren
    I don't see how the wheels would ever be strong enough to support the weight of a normal sized human. I would think that the wheel rollers would have to come down to the bottom of the wheel.
  • I actually picture something a bit wider and sits lower for this application. of course that strays completely from the Brad's intention. Does seem that the back roller would have to sit against the wheel bottom or at least have an extension that supports that area and allows travel. That may even improve the mechanism for braking.
  • Hope you don't have to get off in a hurry. That top tube looks like a castration device. Maybe the tube should come off of the bottom of the seat instead of the front.

    Hubless designs have always looked good on paper, but I think you don't see them implemented more because the higher stress requires more rotating mass. Tensioned spoked wheels are incredibly weight efficient. I believe the front wheel will collapse very easily. Try some FEA.You might read The Bicycle Wheel by Jobst Brandt of HP. I worked with him a little while I worked at Avocet developing a tensiometer for bike spokes.

    Gearing looks to be an issue. The drive gear is going to have to be severely geared up to be equal to conventional gearing. Driving the center of the wheel as opposed to the circumference gives a big mechanical advantage. Can't see what's going on inside the rear arm, but there had better be a 50-100:1 gear up.

    Also, I don't see how the wheels are actually constrained.

    The headset bearing is going to require a bit more separation top to bottom. Conventional headsets are already very hollow, in keeping with the hubless/hollow concept.

    The huge bottom bracket bearing could work well, and eliminating the solid axle might save some weight.

    I worked my way through college in bike shops, and then when I graduated worked at Avocet in California, who made mainly speedometers, but also altimeters, seats, tires, shoes, and tensiometers.
  • I actually did a research paper back in high school referencing that book! Small world! Amazing insight and theory into the structure that is the bicycle wheel. Some of the concepts I still have a hard time grasping.
  • man Matt, that work at Avocet would be interesting. I see a lot of bike designs but I think there's a lot of aspects that are missed on the very preliminary design/engineering aspects.

    I understand the idea of getting the form across. I like how it pushes engineering the mechanism to figure out new ways to do things. But even the form can benefit from even a minor amount of analysis.

    Thanks for the excellent feedback.
  • Dale Dunn
    Another limitation of these designs is higher drag from turning the wheel bearings so much faster.
  • Steve D.
    Seems like any lateral force would twist the wheel in its mounts.
  • I think a channel, which would actually be kind of a partial hub could take care of this. Lateral forces definitely need to be considered.
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