[*BCM*] Fwd: [phonography] Cycling recordists

[Ian Thistle]

My physics are rusty, or weren't that great to begin with, but I believe
it's harder to power extra mass when it is on your wheel as opposed to on
your bike somewhere else.  There are specific terms for this I'm forgetting.

On 1/7/06, Thomas John Vitolo <tjvitolo at bu.edu> wrote:
>
> I stumbled on this while looking up ways to
> > generate power.    http://www.freelights.co.uk/   it seems to be a
> > nice way to make your bike visible without making it more difficult
> > to
> > ride (friction and so on).  The key is the magnet tumbles past one
> > of
> > the magnets on the spokes and thereby creates electrical current.
> > No
> > physical turbine gets cranked, which seems amazing to me not being
> > much of an electrician.
>
> It still makes it more difficult to ride.  After all, you've now got to
> (1) work
> harder because you've added weight to your wheel and have to "lift" it,
> and (2)
> the magnetic force of when the moving magnet approaches the generator
> results in
> resistance.  Think of pushing a magnet toward another like magnet.  Sure,
> it's
> not much resistance in either case, and you get the added bonus of
> recovering
> nearly all of the force when (1) the magnets get to "fall" and (2) the
> generator
> pushes the magnet away once it's past.
>
> But, no machine is perfectly efficient, so there is a 100% chance that
> this
> frictionless dynamo system makes it harder to pedal than no dynamo system
> at
> all.  How much harder to pedal?  Probably not much.
>
> - stomv
>
> P.S.  Since your cycle will have more mass with the dynamo system on, you
> will
> face more rolling friction when you ride, it's just that the friction
> isn't on
> the dynamo, it's between your wheels and the road.
> Support a few technologists in Washington.  Go to:
> http://actblue.com/list/stomv
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