Magnetic gears, for a bicycle. Chainless bike, dragless drivetrain

[Cherryman]

Now this one is intresting too

http://www.youtube.com/watch?v=ludLU4_6ZDM&feature=related

[Cloxxki]

Now this one is intresting too

http://www.youtube.com/watch?v=ludLU4_6ZDM&feature=related

I saw that also.
From a small "chainring" it gets the "wheel" turning quickly, at a 90º angle.

The obviously weak torque is however introduced as a convenient safety feature. On a bike, it would not make it up the slightest hill.

I am very much interested to learn whether a magntic gear link can be boosted turning the sytem (partly) into electromagnets. If possible, it might get a strong link from an otherwise feeble bunch of zen magnets, to offer an example. There's some nice zen magnet gearboxes out there on Youtube.

@Cherryman ik heb je een bericht gestuurd.

[neptune]

I have been watching this thread with interest , but have refrained from posting to let other people have a say .On a world wide scale , the bicycle is by far the most used form of mechanised transport . Its great advantages are low cost and efficiency . Whilst chain drive has its drawbacks , a well maintained chain can have an efficiency of 95% or better . It is easy,light , and cheap to replace . The bike is the nearest thing we have to a practical overunity device . Although it is NOT OU , it is typically 3 times as efficient as walking ! I do not say that it is incapable of improvement , but that is not going to be easy . If it is not broke , do not try to fix it . Any device that replaces the chain drive must be lighter , or cheaper , more efficient , or more long lived . Or preferably all of the above . And that is a tall order . If you really want to improve the bicycle , invent a combined battery/motor unit that weighs less than a Kilogram and has a range of at least 100 miles , at a speed of not less than 15 Miles per hour . On the other hand , full marks for thinking about it .

[Cloxxki]

@neptune:
Having been born in the Netherlands, and having designed some currently available performance bikes, I am well aware :-)

The bicycle is one of those technologies which was near perfect from the get-go in the 1800's. Double triangle frame, steel chain.

I am not only looking to improve efficiency, but also remove drivetrain maintenance (and grease).
And for a very specific application, where a chain just gets in the way of the feet. If you want to know: fat bikes. Mountainbikes with bicycle tires that resmble donuts, 3.7-4.8" wide. The wide tires themselves pose some fitting and compatibility issues, it would be great to remove the chain.
And for super high-speed road- and track bikes, not having an external drive train at all would reduce air drag, and enhance esthetics (very important for bike enthusiasts).

If I consider a regular chainwheel and chain, where the chainwheel's teeth are shallow, resulting in limited torque capability, to compare to a magnet gear:
When the chainwheel would be turned into an electromagnet, the chain would stick much better to the chainwheel, and skip over the teeth only at much greater torque figures. Presuming a well-tensioned chain, I don't see the chain suffering ill affected from the magnetic attraction. Releasing the chain costs the same as the initial pull delivers, right? I am interested to learn the Energy used up by such a magnetic chainwheel, and then extrapolate that exemplary concept to true magnetic gears. Just boosted. I honestly can't figure out how to calculate battery use for such an electromagnet, as it would not be performing visible work, only prevent mangetic skipping.

I see that the torque on such system is limited, so I'll think both of a high-surface-contact type of interface, likely with multiple contact points, inverted magnetic chain wheels, but also this boost option. And if the boost would aid in larger air gaps, that would help a lot also.

Thanks for any thoughts,

J

[Cherryman]

Hi J,

Got your mail and replied.

OT: I did some thinking on your terrain donut wheels and have made a little concept in my head.

I will see if I can make a drawing.

Would you mind it if the tires were adjustable  for terrain and high speed surface on the fly?  ;-)