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  • Hacker News
  • So Black Mirror lied to me ?!
    by xyzsparetimexyz
  • Tried one at a demo; you put in a ton of work for minimal wattage. Much better off with a decent power bank, honestly.
    by Mugshelf
  • > An energy loss of 42 to 67.5 percent of naturally means that it takes 42 to 67.5 percent more effort or time to power a device (say, a blender) via electricity compared to powering the same device mechanically.

    Nope. If input is 100W, loss is 60%, and resulting in output of 40W, then to increase output to 100W you don't need 60% more input (which would output 64W) you need 150% more input.

    by mmooss
  • You could attach pedals directly to motor axle and control charging power drawn precisely to ensure smooth rotation in absence of the flywheel. It could be really small.
    by scotty79
  • No, you can't. Most generators have to be spun at a thousand or several thousand RPMs to put out any sort of amount of power.

    Your average inexperienced person can pedal at maybe 80rpm comfortably, but probably considers even that to be "fast."

    A road cyclist with a year or so under their belt will do 100rpm if they put their mind to it and are positioned well biomechanically. Above that, to do it and be smooth and efficient, especially for any sort of sustained effort, you have to have a decent amount of experience/training.

    That's well over 10x too slow.

    And there's still the issue of your average person only being able to put out 100-200W past about 1-3 minutes.

    by KennyBlanken
  • I'm suprised that the author didn't consider dynohubs which were also a thing in back in 2011, and are getting slightly better all the time.
    by fergie
  • Are there options that don't limit the output power? Typically the light power is limited, so dynamos only provide around 5 W or so, which already makes them not so attractive even for charging your phone on a bike.
    by ygra
  • > dynohub

    Thanks, I learned something. I’m suprised how little drag they seem to add.

    https://www.cyclingabout.com/dynamo-hub-power-drag-testing-s...

    by lostlogin
  • Some things I would like to see are pedal controlled devices. Something like a pedal controlled wheelchair, not powered by the pedals just control the forward and back motion. My mother with sever arthritis can still pedal but has a very hard time walking. It would be a little exercise doing something that needs to be done (getting around). A pedal controlled remote control lawnmower would be nifty also.
    by tocs3
  • many ebikes work this way, pedaling and the chain more or less signal the motor rather than provide meaningful power... though afaik none of them do backwards for obvious reasons

    she might enjoy an etrike, though more for recreation than normal day to day

    by micromacrofoot
  • Have you seen what people are doing with hoverboards + wheelchairs? Carer- & user-operated variations. Not professional solutions, but certainly fill a need.
    by Walf
  • This seems close to what you're describing: https://www.icetrikes.co/products/pers-chainless-e-assist-sy...
    by Zambyte
  • Where I used to live an elderly gent rode a very low to ground bike. Looked a lot like the silly motorbikes some peeps do. I imagine they’re out there for sale.
    by grebc
  • This arguably had some relevance in 2011. In 2026, cheap solar and batteries make human-powered static devices that would benefit from the extra power of a stationary cyclist completely redundant.
    by rgmerk
  • Might have changed their attitude since then as they posted in 2022 about a DIY guide on making a bike generator: https://solar.lowtechmagazine.com/2022/03/how-to-build-a-pra...
    by erelong
  • > Our dashboard also includes a 220V circuit. That makes it compatible with grid-powered devices (110V in the US, 240V in the UK).

    Retro-look nit: all are outdated nominal voltages. The US is 120 V (since the 1960s), while the UK and EU are 230 V (since the mid-1990s).

    by wumms
  • I thought he was posting about some retro product until I saw the USB ports in the energy delivery. Weird that he edited his photos to look like that, and used retro components otherwise.
    by NewsaHackO
  • Needs "2011" in the title. For example the section about friction drive hasn't been true for about a decade now
    by usrusr
  • Nobody would (or should, at least) be using a lead-acid battery for this in 2026, either.

    Full-cycle efficiency should be higher now. And the inverter. And the generator.

    by allenrb
  • Not to mention they’re talking about lead-acid batteries, which have been replaced for pretty much every application, except (for now) starter motor batteries for combustion vehicles, by the various lithium batteries.
    by rgmerk