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| Monocaster |
 Title text: My competitors say the tiny single tiny caster is unsafe, unstable, and offers no advantages over traditional designs, to which I say: wow, why are you guys so mean? I thought we were friends! |
Explanation
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This explanation may be incomplete or incorrect: Created by a LAPTOP-CONTROLLED HAMSTER BALL - Please change this comment when editing this page. Do NOT delete this tag too soon. |
A caster, also spelled castor, is a small unpowered wheel, usually attached to a swiveling base. They are typically found on carts and office chairs to make them easy to move, and may be placed on heavy appliances to facilitate movement.
Randall has proposed a variant of the skateboard with only one caster on the bottom, the titular "monocaster", and devoted most of the comic to a perceptual map showing the variety of wheeled vehicles. Market strategists and investors use such diagrams as a simple way of representing important differences between products or companies, but where a consumer might be more concerned with features like speed, cost, ease of use, or carrying capacity, this map focuses on the number of wheels (horizontal axis) and the diameter of those wheels (vertical axis).
Each axis uses a logarithmic scale, which is convenient for making the map look empty but also visually exaggerates the size of the "key gap" that the monocaster is filling, which can be described as "vehicle with a single wheel smaller than 25 cm". The nearest competitors appear to be a two-wheel skateboard sometimes called a caster board (wheel diameter under 8 cm) and a single-wheel self-balancing board resembling a Onewheel (diameter around 25 cm). The Onewheel is sometimes described as a monowheel (though these are traditionally larger like the "1920s monowheel" on the upper left). Randall appears to have combined these two names to create the monocaster. This gives up several of the competitors' features - the caster board's two wheels provide enough stability to propel the vehicle manually, while the Onewheel's single wheel is wide (assisting with sideways balance) and powered by a self-balancing mechanism.
The result resembles a "Sphere-and-ring" balance board, or other types, though these provide limited locomotion potential. The joke depends on the caster's obvious impracticality in this role: the hole in the market was open for a reason. The obvious drawback to any single-wheeled vehicle is that it's difficult to balance: the rider has to avoid falling forward or backward, as well as to either side. This is a major reason why one-wheeled vehicles are uncommon to begin with, but those vehicles which do exist compensate by using relatively large wheels, driven either by human power or a motor, which creates rotational inertia and allows the rider to balance simply by leaning forward.
A single, small, undriven wheel eliminates these balancing forces, meaning that the user would essentially need to balance on a single point. Also, most casters swivel, meaning that the balance point would move around under the rider's feet and make it even more difficult to balance. In addition, there's no apparent means of propulsion, which means the only way to move forward would be to either roll exclusively downhill, or use one foot to push off the ground. Either strategy would make retaining balance almost impossible.
Multiple wheeled vehicles greatly reduce the issue of balance simply by having multiple points of contact with the ground. The size of the wheels varies greatly; small, rigid wheels are generally suitable only for flat, smooth, rigid surfaces at relatively slow speeds, while vehicles expected to handle high speeds and varying road (and off-road) conditions will necessarily have larger wheels.
The "monocaster" design offers no advantages and would be nearly unrideable, making it obvious why such a vehicle has never been seriously proposed.
The title text extends the joke by listing the disadvantages mentioned above, but not providing a rebuttal. Instead it only attempts an emotional appeal by saying that the competitors are being mean and by commenting that Randall believed they were friends.
| Vehicle | Number of wheels | Wheel Diameter | Explanation |
|---|---|---|---|
| 1920s Monowheel | 1 | 3 meters | A monowheel is a vehicle in which the rider sits inside a single, large, hollow wheel. Versions have existed which were hand- or pedal cranked, but the "1920s" version portrayed here is apparently motor-driven. These vehicles have generally been seen as novelties, as their stability and practicality issues limit their usefulness for actual transport. |
| Unicycle | 1 | 45 centimeters | Probably the best known single-wheeled form of transport, a unicycle consists of a single wheel, directly drive by pedals, with a seat mounted on top. Due to their difficulty, they're generally been used as novelties and for comic performances more than as practical transport. |
| OneWheel | 1 | 20 centimeters | A one-wheeled electric skateboard in which the user stands on both sides of a large, central wheel. The design self-balances by increasing the velocity as the user leans forward. This allows balancing and speed control to operate in a single motion. |
| Bicycle | 2 | 45 centimeters | A two-wheeled, pedal-driven vehicle. The relatively simple, inexpensive and efficient design of these vehicles makes them practical for transport in a variety of situations. As a result, they've long been among the most popular and widely produced vehicles in the world. |
| Scooter | 2 | 8 centimeters | A two-wheeled vehicle driven either by pushing with a foot or by an electric motor or fuel-powered engine. Scooters are ridden both for recreation and as a form of transportation in cities. |
| Heelies | 2 | 1 centimeter | |
| Tricycle | 3 | 20 centimeters | |
| Scooter (three-wheeled) | 3 | 3 centimeters | |
| Monster Truck | 4 | 2.5 meters | |
| Car | 4 | 50 centimeters | |
| ATV | 4 | 20 centimeters | |
| Skateboard | 4 | 2 centimeters | |
| Three-Wheel Skates | 6 | 4 centimeters | |
| Roller Skates | 8 | 2 centimeters | |
| Semi-Trailer Truck (Articulated Lorry) | 10-18 | 1 meter |
Transcript
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This transcript is incomplete. Please help editing it! Thanks. |
- [A chart picturing many wheeled vehicles with a caption below the chart window. The vertical axis is labeled "Wheel Diameter", logarithmic from 1cm to 5m. The horizontal axis is labeled "Number of wheels", logarithmic from 1 to 16. From top left to bottom right, there is a person with a cap, seated in a circle, labeled "1920s monowheel", a monster truck with a skull and a lightning bolt on the side, a lorry (truck), a Cueball on a unicycle moving back and forth, a Cueball on a bicycle, a car, a Cueball using a Onewheel, a Cueball on a child's "Big Wheel" tricycle, a Cueball on a quad, a Cueball standing on a scooter, a Cueball standing on a board with one small wheel bellow, circled and labeled with two question marks, a three-wheel scooter, a skater, a Cueball using three-wheel skates, labeled "three-wheel skates", a Cueball crouching and using skates, and a small Cueball using shoes with wheels (Heelys) moving forward.]
- Caption: My new monocaster board fills a key gap in the wheeled vehicle market.
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