I have no reason to doubt their claims, but I do not remember fondly dynamos that ran on the rim—especially in icy conditions. Hub mounted dynamos were a considerable step forward.
So, they put a supercapacitor between the rectifier and the output to stabilize the voltage. This is old technology. The reason why so few cyclists use a dynamo nowadays is not because of the voltage instability, it's because a dynamo slows you down, and because good, long-lasting and rechargeable batteries are ubiquitous.
Absolutely. I will stick with my 80USD shutter precision hub dynamo. 5W of output is plenty for charging in the day and lights at night, and I don't even notice the drag.
The reason people don't use dynamos often is that good ones cost $300 + another hundred + for the lights, and if you're spending that much money, you're serious about wanting to ride all night without worrying about batteries dying.
If you're out for a couple of hours, batteries are grand.
I wanted to buy a dynamo because I was driving long-distances with smartphone navigation and listening to audiobooks, and my smartphone was dying after about 6 hours.
I looked at the options and bought a $50 20000 mAh powerbank instead. Enough to charge the smartphone 4 times and the lights basically forever.
Dynamo is much more likely to break than the batteries, less convenient, and more expansive. It's obsolete technology IMHO.
I've put about 7,000 commuting miles on my SON hub in all weather conditions. The previous owner put another few thousand on in maintenance conditions I don't know the particulars of.
I expect I'll need to service it in another few years.
In the meantime, I've gone through at least three reasonably priced battery packs; two because they crapped out, and the last because i wanted USB-C.
I'll take the dynamo hub any day for my bike lighting and power needs.
oh, and as an added benefit it's way less of a hit on the environment!
I was thinking about going with a dynamo wheel on my touring/camping bike when I realized that instead of building a $200-300 3 watt dynamo wheel I could use a 28 watt solar charger on the rear rack for $50. Not to mention batteries have gotten so big/cheap and places to charge are all over the place.
This is out of date. Battery powered lights are now also allowed in Germany. But most bikes have hub generators instead of dynamos these days. The most fameous one is the Son (https://nabendynamo.de/en/products/hub-dynamos/)
Apparently, the avg cyclist in the city pedals at 50W to move forward. Now, imagine you'd have to power your USB charger at 20W at an 80% efficiency factor (which is what current high-end hub dynamos manage regarding efficiency):
Your avg city biker will only have left half of his pedal power to move his bike across town.
I recently came across a quite new rim dynamo [1] which seems to have bearings that last for ~15.000km which might be a real alternative to hub dynamos regarding efficiency. Never had the chance to try one so far since my hub dynamo is still going strong.
I would doubt this number. Do not as k why but I have an actual power meter (Powertap) on my bike and being average Joe Schmoe I do about 150 Watts when doing semi leisure ride of 50 km (31 miles) on a flat. On such ride I pass some and many pass me. My best ever result on the same ride when I was going like mad all the way was 250W.
I would assume that I am pretty average so 100-200W would be more likely number rather then 50W.
I can't tell if they are claiming 4x efficiency over the other rim generators. Seems unlikely. The alternative is they make 3-4x more drag, which would be ok if you need that much power. Google Maps does burn quite a lot.
Four years in development? Maybe they got an engineering degree in the meantime?
It's maybe a little unfair to say it's just a regular generator with a supercapacitor. They must have a $.50 power converter in there, and a microcontroller to negotiate USB charging voltage, maybe $1.
But tooling for plastic molding is super expensive for low volumes.
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[ 2.4 ms ] story [ 49.5 ms ] threadSo, they put a supercapacitor between the rectifier and the output to stabilize the voltage. This is old technology. The reason why so few cyclists use a dynamo nowadays is not because of the voltage instability, it's because a dynamo slows you down, and because good, long-lasting and rechargeable batteries are ubiquitous.
If you're out for a couple of hours, batteries are grand.
I looked at the options and bought a $50 20000 mAh powerbank instead. Enough to charge the smartphone 4 times and the lights basically forever.
Dynamo is much more likely to break than the batteries, less convenient, and more expansive. It's obsolete technology IMHO.
I expect I'll need to service it in another few years.
In the meantime, I've gone through at least three reasonably priced battery packs; two because they crapped out, and the last because i wanted USB-C.
I'll take the dynamo hub any day for my bike lighting and power needs.
oh, and as an added benefit it's way less of a hit on the environment!
$299 for basic off the shelf circuit, supercapacitor and dynamo? LOL. Does it come with rounded corners?
https://en.wikipedia.org/wiki/Bicycle_lighting#Legal_require...
If you want to charge your phone, support a small shop and get you a sinewave: https://www.sinewavecycles.com/
Your avg city biker will only have left half of his pedal power to move his bike across town.
I recently came across a quite new rim dynamo [1] which seems to have bearings that last for ~15.000km which might be a real alternative to hub dynamos regarding efficiency. Never had the chance to try one so far since my hub dynamo is still going strong.
[1] http://www.velogical-engineering.com/velogical-felgendynamo-...
I would assume that I am pretty average so 100-200W would be more likely number rather then 50W.
Four years in development? Maybe they got an engineering degree in the meantime?
It's maybe a little unfair to say it's just a regular generator with a supercapacitor. They must have a $.50 power converter in there, and a microcontroller to negotiate USB charging voltage, maybe $1.
But tooling for plastic molding is super expensive for low volumes.