Big Wheels

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In the past few days, several readers have pointed me toward a recent Gizmodo post about a monocycle replica from 1873. The replica, which was handmade by a man in Spain, features a 6.16 foot diameter wheel. The workmanship is very impressive and the machine itself looks like it would be a lot of fun to ride. Be sure to check out the eBay auction for another picture. The auction has ended at this point with out anyone responding to the $13,000 opening bid. Yeah, that is a lot of money, but some modern production bikes cost half that amount and this is a one of a kind creation. You certainly wouldn’t have to worry about seeing another bike just like it on your local group ride

Just over 6 feet is a large wheel diameter, but it isn’t the largest that I have seen this week. David at the About.com Bicycling page posted about the Hyperbike (pictured here), which features two 8-foot wheels that are angled in at the top like a racing wheelchair. The machine’s designer, Curtis DeForest, was inspired in part by competition wheelchairs, which are very fast with a low center of gravity. One of the design goals was to make the machine as fast as a car on flat ground. The website explains:

“The circumference of an eight foot diameter wheel is roughly twenty-five feet and cadence, or the rate at which a person pedals, is most comfortable at a rate of 13 beats every 15 seconds. Gearing that allows an operator to rotate the wheels four times each pedal cycle, or at a 1:4 ratio while at the comfortable cadence rate will produce a speed upwards of 50mph.”

Certainly this design is very different from the majority of the bikes that you see on this site, but I think it is quite interesting. I encourage you to read the articles on the website, especially this one from the East Hampton Star. It sounds like this machine/trike would require a bit of practice to ride comfortably, but I would absolutely love to give it a try. Now that NASA is contributing some engineering expertise to the project, I am anxious to see Mr DeForest’s next prototype.

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6 Comments

  1. Fritz August 17, 2007 at 11:42 am -  Reply

    It’s kind of cool to gawk at and it looks kinda fun, but the designer went at it to attack non-problems:

    * “The conventional bike is unstable.” FALSE: a bicycle is inherently stable.
    * “The bicycle is more vulnerable than a pedestrian.” FALSE: Pedestrians have a much higher injury and death rate due to motor vehicle collisions than cyclists do.
    * “Cyclists are unable to travel at the speed of traffic.” FALSE: Bikes are traffic.
    * “The Hyperbike’s large wheels makes it… fast.” FALSE: The major impediment to fast speeds on a bicycle is air resistance. Overcoming air resistance goes up with the square of speed. I’d like to see this bike really do the claimed 50 mph on level ground.

    And what’s with the wetsuits on the models?

  2. James August 17, 2007 at 12:22 pm -  Reply

    Fritz, I agree with your points and I would add that the size and weight of this machine alone is a disadvantage in many ways when compared to a traditional bicycle.

    Still, I think it is an interesting idea if viewed, not as an improvement to the bike or even to other HPVs, but as just another option for Human Powered transport. You are absolutely right that bikes are traffic at any speed, but even though that is the case, I definitely make an effort to ride faster when I am on a heavily trafficked 2-lane road. I feel safer in the lane if my speed is closer to that of the cars on the road.

    Like you, I am skeptical of the speed claims, but I still think it is an interesting machine. I mentioned a few posts ago that I don’t believe that designs that use all four limbs are efficient (legs are much stronger than arms and you still only have one heart and one set of lungs). Still, I look forward to seeing how the inventor develops his idea with the bit of engineering assistance from NASA that he has been granted.

    Practical or not, I have to say this thing piqued my curiosity. Then again, maybe it was just wetsuits.

  3. Anonymous August 17, 2007 at 6:39 pm -  Reply

    I like how it kind of has a roll cage, and how visible it is to cars. I don’t like how the large spokes on the wheels are not streamlined, which is odd since if the bike were to go at 50 mph, the top of the wheels should be going close to 100 mph. I’d give it more consideration if it were a multi-person model…

  4. bmike August 20, 2007 at 8:52 am -  Reply

    ahhh. this has been around the blog block before.

    good luck to the guy getting it to work, but i doubt it will go anywhere. can’t imagine lugging that thing up and down hills, nor using your body to help with handling. what’s with standing bolt upright? if it is going to replace cars, shouldn’t there be a seat in it for when i can’t get those big wheels between lines of stuck autos? or for when my trip is longer than a run around an empty parking lot?

    the designer also claims that ‘regular’ bikes are not comfortable. he’s clearly never ridden for very long, or far, with a proper fit, and a proper saddle, on a proper bike.

  5. bikesgonewild September 22, 2007 at 3:23 am -  Reply

    …i’m a month late to the party here but, this is a big wheeled recumbent that the designer negleted to put the cockpit in the right position…
    …size the wheels at least a 1/3 smaller w/ real world spokes…big wheel trade off…big enough ta be seen==safer in traffic // too big, slow acceleration==dangerous in traffic…
    …forget the hand cranks if ya want comfortable stability at speed…good point ‘a la’ physiology, james…
    …how many engineers come outa school, define the “problems” and then declare they’re gonna reinvent the bicycle ???…fritz seems ta nail those imaginary problems…
    …anyway, cool ta look at, way too big to be practical, love ta try it out…

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