A No-friction bicycle light dynamo

In article <[email hidden]>,

Quoted message said:

This is a new generation bicycle light system based on a newly
invented generator.

No battery is needed, no friction on any parts of the bicycle.

So many people are scared of the little bit of extra wattage
of rider output, and a little bit of slowing-down, demanded by
good ol bottle generators.

What a bunch of wusses those people are.

With a /real/ generator, you get real light output. It doesn't
cost that much in terms of rider output. And the light you get
is much better than a single, flickering LED. 'Cuz a generator
headlight makes a nice, broad disk of light source, and is
steadily shining.

With your thing, one could more easily go to the dollar store,
get a cheap flashlight thingie, tape it onto their bike, and
have something superior to your product.

So, thanks, but no, thanks.

--
Nothing is safe from me.
I'm really at:
tkeats curlicue vcn dot bc dot ca

Quoted message said:

This is a new generation bicycle light system based on a newly
invented generator.

No battery is needed, no friction on any parts of the bicycle. The
lights flash regardless speed of the bicycle and weather conditions
(unlike normal dynamos!). More details onhttp://www.freelights.co.uk

Looks like a Reelight, but with wires. A sixth of the price of a
decent dynamo hub + LED headlamp, and probably about a sixth as useful.

Quoted message said:

Quoted message said:

This is a new generation bicycle light system based on a newly
invented generator.

From the site:

Quoted message said:

This Non-friction bicycle dynamo won't slow cyclist down.

Free energy?!? Wow! (oh, or did you mean 'perceived slowdown'?)

BTW, we built such 'generators' (magnet passing a coil of wire) in
elementary school, nothing new about them.

Rex Kerr said:

Quoted message said:

Quoted message said:

This is a new generation bicycle light system based on a newly
invented generator.

From the site:

Quoted message said:

This Non-friction bicycle dynamo won't slow cyclist down.

Free energy?!?  Wow!  (oh, or did you mean 'perceived slowdown'?)

BTW, we built such 'generators' (magnet passing a coil of wire) in
elementary school, nothing new about them.

The "new" part of this is that the magnets on the wheel cause another
magnet to tumble next to the coil. The thinking is that the tumble
speed is faster than a slow-moving wheel speed, so might work better
at slower bike speeds, assuming your energy needs are small. A
flashing LED or set of LEDs is, indeed, a fairly small load.

I'm not defending him - there will obviously be some magnetic drag,
and based on the fact there's a 'quietized' version now, there's
obviously some wasted energy, too. Personally, the rattle is what
would kill the idea for me.

Brian Huntley said:

Rex Kerr said:

Quoted message said:

> This is a new generation bicycle light system based on a newly
> invented generator.

From the site:

Quoted message said:

This Non-friction bicycle dynamo won't slow cyclist down.

Free energy?!? Wow! (oh, or did you mean 'perceived slowdown'?)

BTW, we built such 'generators' (magnet passing a coil of wire) in
elementary school, nothing new about them.

The "new" part of this is that the magnets on the wheel cause another
magnet to tumble next to the coil. The thinking is that the tumble
speed is faster than a slow-moving wheel speed, so might work better
at slower bike speeds, assuming your energy needs are small. A
flashing LED or set of LEDs is, indeed, a fairly small load.

I'm not defending him - there will obviously be some magnetic drag,
and based on the fact there's a 'quietized' version now, there's
obviously some wasted energy, too. Personally, the rattle is what
would kill the idea for me.

On a lark, I bought one of these. You are correct -- the rattle is
annoying.

Here's my review from 2005:

Some weeks ago, when rec.bicycles.misc was last the beneficiary of this

commercial message said:

But to get back to the O.P. -- he's been occasionally dropping
these messages into this newsgroup for some time. Anybody
actually TRIED these? Well, I suppose not, or somebody would
have posted their experience. So, in the name of science, I've
just invested $19 for a set, and I'll report back in a few
weeks.

The package arrived quickly, but not completely. I wrote at the time:

<<Report #1:
The package arrived. It was a small package, with a bunch of parts
inside. There were no instructions, although there are instructions on
his website
http://www.helpyou.freewire.co.uk/install.html
which seem clear enough.

[Current edition says "new generation", but it looks like the same thing to
me.]

Unfortunately, the movingmagnet and magnet supporter bracket were
missing. This looks similar to a standard bike computer magnet, but it
might be bigger. [it is] >>

I was quickly sent a replacement, but then this project sat on my workbench
for a while. Last night I put it on and tried it out.

First, how does it work? As Ray Heindl noted:

Quoted message said:

The wheel magnet causes another magnet, inside the generator, to flip over
as it goes by. The flipping motion is what generates the power. So
the air gap doesn't particularly matter, as long as the wheel magnet is
close enough to cause the other to flip. At least, that's how their
web site explains it.

The magnet doesn't seem to need a highly precise gap -- it seems much less
finicky than a bike computer magnet.

Second, does it give off light?

Every time the wheel rotates, the front and rear LED's flash. This is a
substantially lower flash rate than a regular blinky. The rear 3 red LED's
are easily bright enough for usage, although they are considerably less
bright than my usual Cateye blinky with a plastic lens over the LED's and
fresh batteries.

The front has two white LED's which I would rate as better than nothing on
the "be seen" light stage. You won't be seeing much with them.

Third, what's the drag?

There is perceptible drag. This was most easily shown while I had the bike
on the bike stand. Ordinarily, one can spin a rear wheel and it keeps
spinning for a while. In this case, the drag caused by the magnets led to
substantially less time before the wheel stopped. Rotating the wheel by
hand, you can clearly feel magnetic attraction when the magnets pass each
other.

There's no way to turn it off, so you get this drag all the time. The drag
is significantly less than the AXA generator I have on the front tire of
this bike, but then that's powering a standard 3W headlight and can be
turned off. It was windy last night, so I can't say whether the drag is
perceptible in actual use. I don't have the equipment or EE knowledge to
compute efficiency, so it may very well be pretty good. Maybe Frank K. will
buy this thing off me, so he can do the calculations? 😉

Fourth, what's that noise?

When the magnets pass each other, the magnet inside the generator flips over
against the plastic wall of the generator. This is pretty noisy. I kept
thinking that the spoke magnet must have become dislodged and was banging
against the generator. Like most cyclists, I'm not fond of
metal-against-plastic noises that occur every time the wheel rotates and
tend to associate them with bad things happening. This would eliminate the
need for a bell, though 😉

Fifth, what's next?

This is on my winter bike, which gets ridden a lot at night, so I'll
probably leave it on there for a while just to see if my opinion changes.
The noise is the thing that seems likely to bother me most.

[Eventually I took it off. It's not a bad idea, but not terrific either.]

Fuller discussion from 2005 at:
http://groups.google.com/group/rec.bicycles.misc/browse_frm/thread/6a61a296d7a2a850/94b88db5e0c3c977?hl=en&lnk=gst&q=friction+light+kruger#94b88db5e0c3c977

--
Mike Kruger
Say not always what you know, but always know what you say.
Claudius; 10 BC-AD 54, Roman Emperor