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That looks pretty cool but wonder if they will work with fenders.

the Q&A at the bottom says it's got a classic setup option for above the wheel, which needs wires to connect the LED and dynamo, since you can attach it to the brakes (which you can have with fenders) I'd say it's a solid maybe (initial look made me think no). It's a question worth asking.

eddy current technology... sometimes physics is downright creepy. At least it's useful, and these guys are harnessing it for good, not evil.

"Although there is no friction the absorption of magnetic fields has a minimal breaking effect, so we don't get energy for free."

This is what I was afraid of. I'm curious whether this braking effect is stronger than it would be with a hub, or with contacts, etc. 150 lumens is not ultrabright but $130 is not a terrible price for a 150 lumen light these days when you consider that it has no battery.

He has a video showing a side by side comparison with a hub dynamo. His wins.

Another thing I like is that if he makes the mount with a hinge the light can be swiveled away from the wheel when not in use, eliminating friction completely. Not possible with most hub dynamos.

definitely interesting but I'll wait for the separate light version. Not sure about fender interference but obviously that taillight is not going to work with a rack.

@ salty

I think it could work with a rack - you would just have to fasten it to the rack or frame instead of the brake.

Now, they claim Magnic Light has the comfort of a strong battery light .

I call BS on that.

A light that goes out whenever I stop is not a comfort in the traffic. Even on a dark country trail that could be disconcerting.

They ahve no batteries but I think they would be better off with a little rechargable or a capacitor, so the light would persist when the bikes at rest.

The back light on the brakes getting brighter when you apply the brakes is a clever idea. Yay! Brake lights!

But I suspect that you could end up with a very dim light when the brakes aren't on. And perhaps overpowering when applying light brakes on a long fast hill? Anyone know know how easy it is to burn out a LED?

It looks like the front light is also attached to the brake and would have the same effect.

I'd guess that the light would be hugely brighter with steel rims. (I could be wrong.)

Would a magnet used like this become demagnetized eventually? Dunno.

I would think of this light as a companion light to a bright/traffic alerting headlamp. In particular because the front light seems to light up the road in front as you move... so it would be a pretty good pothole light. Probably not as idea for traffic alerting because as you say it goes out when you stop. Which makes the rear light seem less useful, as it doesn't stop people from hitting you from behind at a stoplight.

My point re: friction isn't that his wouldn't be better, but just that it would be interesting to know actually how much magnetic friction there is... e.g., same exact pedaling on the same exact route on a bike without the light results in 1% slower with the light. Just out of curiosity. I don't think his hub comparison is completely fair because you don't know what light is being used, how much power is being drawn, and how much friction there is in the bearings, etc.

I would assume you could adjust the brightness on whatever rims you use by changing the distance between the rim and the light.

The magnet should not be affected by use. It is not used up in any way.

I have the Supernova E3 dynamo-powered lights, which include a standlight powered by a capacitor, but it really doesn't work that well when you are stopped. It is better than nothing, but I have an additional Planet Bike flashing light on my helmet. The combo makes me feel pretty safe. I would imagine something similar would work with this system.

LEDs last a really long time, probably not an issue.

@ jonawebb The magnet should not be affected by use. It is not used up in any way.

Curious - do you have a background in engineering, physics, or electric lighting? Or is your statement, like mine, just speculation?

Pushing a magnet through a magnetic field will affect that magnet. I susect that effect would be to diminish, not reinforce the magnet.

I don't worry about the lifespan of the LED at normal voltages. I've never had one die and mine are years old.

Other than that, I dont' know much about LEDs. A quick Google search yeilds this, though:



Properly designed LED circuits require two very important features to be successful: protection from over-heating and protection from over-voltage.

http://EzineArticles.com/4952010

The article implies that at less than a 50% overvoltage, LEDs can fry.

I didn't see anything on the Magnic site about a protective circuit. I can see the Southside Slopes from my window, though.

I would certainly not be concerned with the LED's life. I would have replaced the light with something new within a year or two anyway, just the way things go.

@Mick, many many devices (including normal hub generators) use magnets to generate electric power, and the magnets are not used up in any way by this use. Magnets have an inherent tendency to keep all the atoms lined up in the same way because of the action of all the other atoms pointing in the same direction. As long as there is not a huge magnetic field driving the atoms the other way they will realign.

I am in fact an engineer but it does not take a degree to understand this, just a basic understanding of magnetics. We do not need to professionalize high school physics (no offense).

@Mick LEDs are most damaged by allowing too much current to pass through them. Things like light bulbs resist current, but LEDs have negligible resistance. Because of this the circuit around the LED has to restrain the amount of current hitting the LED. You know, like when you're telling your drunk friend he doesn't need another drink at the bar? Your friend is an LED. They "burn out" nearly instantly if you allow too much current to pass through them

Also, eddy currents are really cool. Anyone else get this demo in high school physics?

http://www.youtube.com/watch?v=G7ysnXH53Wo

but I never had a physics class, high school or otherwise! aaahhhhhhh! I believe I elected to take "study hall" when I no longer needed any further science credits in high school. Little did I know I would soon be in college disecting a cat. haha

Tabby - you didn't miss much. Lots of talk of infinitesimal particles moving through empty space with mysterious forces imparted to them without any physical objects actually touching them.

Mysteriously the homework assignments were always to extrapolate from the land of frictionless infinitesimal point masses into the land of reality. I always felt so ill-equipped.

/me reminisces of frictionless vacuums.

Hmm...just a few weeks after I spend ~$250 on a dynamo hub and B&M headlight, someone has to go and invent this.

I'd say that it looks like the optics on the headlight could use some refining. In some of the shots the beam looks a little too bright and narrow to provide the field of vision that I'd prefer.

Booooo Frictionless!!! How can you have any headloss without friction?!?!