Half a croissant, on a plate, with a sign in front of it saying '50c'
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Flywheel Unicycle

For stability and going up hills
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(+2, -1)
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Pedalling would accelerate the flywheel and you would have a motorbike style throttle which engages the clutch to drive the wheel.

It would have a kick stand so that you could start pedalling to speed up the flywheel while stationary and then lift the stand once the cycle is stable.

It could also have a regenerative braking system to transfer speed back into the flywheel.

Alternatively, the design could use motors, generators and a battery rather than mechanical gearing.

The only small problem is where to put the flywheel as it would need a vertical axis. Not a problem though if a d=20cm, h=10cm flywheel is big enough, but I'm not sure it would be.

marklar, Dec 10 2010

honda unicycle. http://www.youtube....watch?v=0pkn8Ko-q74
FUlly baked. [VJW, Jan 26 2011]


       Change this to a Wile E. Coyote style affair where you rev up the flywheel with a beefy engine, engage the clutch and it slams you into the ground and you've got a bun my friend.   

       It would also need to be painted to match the crash helmet with lots of lightning bolts and stuff for full effect. The rider should also wear a cape and really cool goggles.
doctorremulac3, Dec 10 2010

       The rider should also wear a cup, kevlar shorts and armor-plated pants.
baconbrain, Dec 10 2010

       ... or diapers.
doctorremulac3, Dec 10 2010

       //clutch//: sp. CVT
//where//: inside the wheel, on the same axis, of course. Then it gives you the same gyroscopic efficiencies as the wheel, only more so. And let it speed up as you pedal away, not spin up first then go.
Actually, thinking about it further (I should be working, but...) you need to be able to connect/disconnect all three rotating components (pedals, wheel, flywheel) in all combinations:
Pedals+flywheel = to add power to the flywheel (if required)
Pedals+wheel = for fore/aft balance control, while not needing flywheel (with the flywheel spinning and pedals controlling wheel directly, you could balance stationary at traffic lights!).
Wheel+flywheel = for coasting without pedaling (not sure that you would want the pedals to disconnect, for balance and control purposes...).
Pedals+wheel+flywheel = normal use. Perhaps have the flywheel spinning heaps faster than the wheel - more efficient (IIRC) that way.
How to do all this on a hub-mounted CVT, controlled by a cabled hand unit, is what makes it halfbaked.
neutrinos_shadow, Dec 12 2010

       [neutrinos_shadow] I assume you have never tried to ride a unicycle. The gyroscope would not help if it had the same axis as the wheel, you would still fall forwards/backwards. Also, you need the stability when you are stationary, not once you are moving.   

       This isn't particularly hard to bake, but for me the difficult part is finding a unicycle. I have a model helicopter motor & gearing which should be ideal for testing out the gyroscope for a couple of minutes.
marklar, Jan 03 2011

       I've tried (and failed...) to ride a unicycle.
With the flywheel axis vertical, if you lean into a turn (assuming you have some speed) you will get tilted forwards or backwards (depending on rotation etc) by the gyro torque effects. The only feasible axis is the axle, spinning the same way as the wheel; otherwise gyro effects will throw you whenever you turn/lean.
On the other hand, having a flywheel heavy enough to do anything useful would probably render the unicycle too heavy to use effectively anyway.
(Sorry if I'm getting a bit carried away here...)
neutrinos_shadow, Jan 26 2011


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