Exotic Bicycle Designs and Engineering

In summary, the author provides a summary of the conversation. The first time the author saw the Kiffy bike design, he thought it was cool. However, the bike is now defunct and is too expensive. The author also liked the Dahon folder for its simplicity. Other interesting transportation modes include the Trikke, the half-bike, and the pedicab.
  • #36
bob012345 said:
Turned by coordinated leaning? Seems like the big wheel would provide a lot of angular momentum making turning harder.

There's a more fundamental problem. Checking this concept against the laws of physics, we see that the sociable monocycle gets its driving torque by moving the center of mass of the riders forward of the axle when they pedal. Notice that the center of gravity of the riders (roughly top of the hip bone) is only slightly below the axle centerline. When they step on the pedals, they will spin themselves around. If they accelerate slowly enough, they could ride on a level road, but that machine will never climb any significant hill.

Just because something made it into print, or even into a patent, does not mean that ever worked. When looking at new ideas or patents, it is always a good idea to check the concept against the laws of physics.
 
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  • #37
UPS is rolling out a pilot program in Seattle and select other cities around the world. Novel in that they are a bike with a trailer. Load both cruise to the area. Drop the trailer. Return transfer loads and repeat. Interesting.
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  • #38
I have a Speciallized carbon fiber bike and use itr every weekend at mountains.
I should make this improvement to increase the pedal arm length by increase the height of the axle to ground.
I thing as larger pedal arm, less times you should make the movement for the same distance.
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  • #39
Suppose the wheels of a standard bike were reduced to skateboard size. Everything else being the same, could the gears be adjusted to make the rider use the same power for the same acceleration? Or would it actually take much more power? I'm thinking the total energy must be the same for the same final speed if the mechanical systems are equally efficient. Thanks.
 
  • #40
My old bike had smaller wheel and I chequed that I make 10-15% better in flat tracks and much better if there are a lot of stones because stones generates a lot more losses to smaller wheels. In hard mountains with >7% up and down I checked no differences.
Asphalt is rought but less than ground tracks and stones not moves so less losses
Longer pedal arm size have closer size to our bones.

LOSSES and FRICTION exist!.
Without friction you can't be stand or take a pencil or make your car to run
 

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