Still in draft at the moment (launches at the end of the month) but this looks quite promising.

Uses magnets (how do they work??) to generate power which you can use to power a light and recharge your phone/GoPro/roadcam etc.

What say the naysayers?

It sounds like they are just externalising the internal workings of a dynamo hub.

Yep – but that’s a good thing because it means you can fit it to any bike rather than getting a wheel built up with a special hub.

Yeah, and making a knock off of the B&M lights with USB output.

And making the dynamo in such a way that you can’t run a disc brake with it.

I’m out.

What’s the projected cost of the full system? Will it be cheaper than an entry level hub plus light? (plus build/spokes if you’re feeling generous)

And making the dynamo in such a way that you can’t run a disc brake with it.

You can fit it to the front wheel on the non-disc side surely?

What’s the projected cost of the full system?

The KickStarter page has the lights-only mini-system for a pledge of $150 (USD) and the usb+lights system for a pledge of $275

So if those reflect the retail price then it’ll be a bit pricier than a dynamo hub + wheel build.

Frictionless? Snake oil right there. I’m out.

And how will it stand up to a wet winters ride?

What’s the projected cost of the full system?
The KickStarter page has the lights-only mini-system for a pledge of $150 (USD) and the usb+lights system for a pledge of $275

So if those reflect the retail price then it’ll be a bit pricier than a dynamo hub + wheel build.

Hmmm, so a pricier uglier solution probably come up with by someone who has not tried a decent dynamo hub system…

I’m still out. Seems a pity if they’ve put a lot of effort into it.

If only someone like Sturmey Archer had thought of this 80 years ago …

And how will it stand up to a wet winters ride?

Yeah that’s the biggest concern for me – looks great on hipsters in sunny Miami. Might struggle a bit in freezing salty road clag. 😀

If only someone like Sturmey Archer had thought of this 80 years ago …

Prior art? Got links?

No Added Friction

Bollocks.

Clearly don’t know what they’re talking about, they might as well claim to have invented a perpetual motion generator.

Demo video is hardly inspiring, the LED front light is barely visible!

Prior art? Got links?

Surely you jest?
https://en.wikipedia.org/wiki/Hub_dynamo

It’s basically a motorcycle stator, isn’t it? There’s no mechanical friction in the generator bit itself but there’ll still be a resistance felt due to the… gaaah… A-level physics don’t fail me now… back EMF (I think). There’s still mechanical friction in the bearings and stuff.

Surely you jest?
https://en.wikipedia.org/wiki/Hub_dynamo

Right, but this isn’t a hub dynamo though – most notably because it’s not in a hub. So I think it would probably pass a uniqueness test for a patent.

Bin done.

http://intelligentdesigncycles.com/product/sunup-eco-ds-1r-spoke-dynamo
Connects to proper lights too as its a proper dynamo.

Not to mention these ones you can get in most shops.

Bikerumor Review – Reel Light Commuter Bike Lights

Surely a normal hub dynamo doesn’t have any friction either (other than that of the axle bearings as per any other hub).

Yup and a whole hell of a lot less exposed too. But as a retrofit I can see the appeal of this system even if it is nothing new.

Always fancied some of those Reel Lights, look like a nice fit and forget option for secondary lights.

Yep, and they suffer from the same issues this one will – that the spacing between stator and rotor has to be larger because there isn’t the same control over tolerances you get if you build it all into a hub, and that increased spacing makes the efficiency a lot worse. As mentioned above it’s only frictionless in the same sense that every other hub dynamo is frictionless – so long as you exclude the friction in the bearings which is just the same for this, and don’t count the magnetic resistance (it’s not back EMF, that’s an electrical thing, but I CBA googling the correct term either).

The quoted efficiency in one of those links is surely BS.

well if you want truly frictionless, then these are what you want (i make no claim of the quality or ability to work or the stupidness of blocking half your light with a tyre).

https://www.reelight.com/en/products/city-supreme/city-supreme/city-supreme-steady-light-set/

I have an Exposure dynamo hub and a B&M front light/USB charger and rear brake and side light. Its very bright, fit and forget, and you can’t tell you have a dynamo hub at all, this new idea doesn’t seem like even half the quality/value. The light looks like Lego, and not good lego either….

At a fundamental level: You move a conductor through a magnetic field to induce an EMF. You can not make the EMF from nothing so there has to be some “work” done and there is your friction in the mechanism.
Make the magnetic field strong enough and cutting the lines of flux with a conductor becomes really, really hard. Try carrying an aluminum ladder through a 3 Tesla field and you know you are working.

Struggling to see any advantages over a set of lights with a couple of AAA batteries in.

As for USB charging never something I’ve felt I needed on a bike. Even iphone batteries aren’t that cr*p.

Back EMF:
As the motor speed increases the eddy currents and the resulting back EMF also increase. When the motor reaches its maximum operating speed back emf will be generated at a constant rate. When a load is applied, the speed of the motor is reduced, which reduces the back emf and hence increases current in the motor. If the load stops the motor from moving then the current may be high enough to burn out the motor coil windings.

Generally, the load slows the armature down and so the current increases as the back emf is decreased. This produces an increase in current and torque to cope with the increased load.

As for USB charging never something I’ve felt I needed on a bike. Even iphone batteries aren’t that cr*p.

If you run your phone as your GPS (Strava/Endomondo/CycleStreets/BikeHub etc) then it could be useful on longer rides – but personally I just carry a little battery pack for that.

dragon – Member

Struggling to see any advantages over a set of lights with a couple of AAA batteries in.

I know one nutter off this forum that decided to go out for a quick ride after dinner one December night last year. Got back to the house around 4am and 160miles later, no battery concerns required.

As for USB charging never something I’ve felt I needed on a bike. Even iphone batteries aren’t that cr*p.

Wireless charging pad on the bars so hipsters can re-charge their iWatch whilst riding their fixie to the cafe for an artisan latte? Seems to be the target market 🙂

This looks like a much neater solution for providing USB power from a hub dynamo:

http://www.rosebikes.co.uk/article/supernova-the-plug-iii-usb-charger/aid:713880

(spendy though!)

I’m glad we’ve established that:

-It looks shit.

-It costs more than retrofitting a decent set of hub dynamo lights.

-It will be less efficient due to the bigger air gap.

-If you want easier retrofit stuff, you can just use battery lights.

I have the B&M light with the USB charger, but I only got it for the remote on/off switch and marginally brighter light – you can’t use the USB charger if it gets wet anyway unless you make an enclosure for it, but as others have said it might work for Iphone latte drinking hipsters in dry places.

You can buy a Kemo USB charger for £30 at Maplins

Very useful if you’re doing a long distance ride. I met a JOGLE rider last week, with something similar on his recumbent bike.

That’s where I’m going wrong I use a Garmin Etrex 10 for GPS and my phone well as a phone. Far lighter, cheaper and no resistance unlike a dynamo (plus non bike specific) and both will last days.

Pfffffffffft

I use a Garmin Etrex 10 for GPS and my phone well as a phone. Far lighter, cheaper..

Not sure how buying and carrying two different devices is lighter or cheaper than just one. 🙂

My bike weights 60+lbs before I haul my lump onto it. The Nexus dynohub/B+M Werk combo charges stuff and powers a bright front LED. The only friction I notice are chafing comments from bike-tarts/pub-bores but even they soon leave me in their wake so I can cruise happily on in the knowledge that am still a smiling, juice-sipping tortoise 🙂

Well I’m assuming you’ll be carrying a phone anyway, so then it is a Garmin vs Dynamo in weight. As for cost basic Garmins are dirt cheap less than £100, no idea what price that dynamo will be but it’ll cost more than that I’m sure.

Which is why I said “personally I just carry a little battery pack for that”. 😀