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[–] 216 points 1 year ago (28 children)

When the battery runs out, you pull over and "pedal" to recharge the battery, then you're good to go again!

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  • [–] 30 points 1 year ago* (25 children)

    I don't own one of these, but that sounds actually useful if for example I'm about to climb a big hill and want to pedal at a less strenuous pace (but for more time) than would be needed to overcome the slope.

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  • [–] 88 points 1 year ago (16 children)

    Assisted modes already exist, and regenerative braking already exist

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  • [–] 8 points 1 year ago* (13 children)

    But do e-bikes have regenerative braking? I haven't seen that. I've been thinking that it would just be too heavy and clunky to be worth it.

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  • [–] 26 points 1 year ago (8 children)

    Too heavy? You just run the motor in reverse which turns it into a generator and adds friction to do generative braking. There really isn't any added weight.

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  • [–] 15 points 1 year ago (3 children)

    Bikes normally have freehubs, a ratchet on the cassette (sprockets) of the rear wheel, when you stop pedalling the bike freewheels, without that the pedals would keep turning.

    This makes driving a motor from the wheel impossible without heavily modifying the normal bike mechanics. That's why regenerative braking on e bikes is rare.

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  • [–] 10 points 1 year ago (2 children)

    Not if you have a hub motor. Those don't interact with the gear system at all.

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  • [–] 2 points 1 year ago

    Only very cheap e-bikes have hub motors. They're not a good idea precisely because they don't interact with the gearing system. So you lose that functionality.

    It's not worth losing access to gearing just to get regenerative braking because the amount of power being used isn't worth trying to recoup.

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  • [–] 6 points 1 year ago (3 children)

    It needs a direct drive which is more weight than the other systems

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  • [–] 5 points 1 year ago (2 children)

    Why would it need a direct drive? A mid drive can do the same thing they just don't usually since you'd need to gear for it. direct drives are the most efficient at regenerative braking but they aren't the only type.

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  • [–] 1 point 1 year ago* (last edited 1 year ago)

    Could be done, perhaps, with significant added complexity (and hence maintenance). In practice it is not, to my knowledge there are no mid-mount regenerative system on the market. It is worth noting that mid-mounts are significantly more efficient than hub mount, enough so that even compared to hub mounts with regeneration, mid-mounts have more range for a given battery / wattage. The vast majority of hub mounts also do not implement regeneration.

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  • [–] 6 points 1 year ago* (1 child)

    Motors are generators when run inversely:

    Motors = put in power to get rotational movement

    Generators = put in rotational movement to get power

    You already have the heaviest parts on the ebike - motor and battery, just need some capacitors and charging circuit board which are light and not too big.

    Cheap electric bikes I've ridden with regen breaking slow you down quite a bit.

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  • [–] 1 point 1 year ago

    It's not difficult to get regenerative braking on a bike it's just difficult to get regenerative braking on a bike that's any good. Hub mounted motors are the least efficient type of motor because it's just directly driving the wheel at whatever speed it can output, with no access to gear ratios. E-bikes that forgo generative breaking in favour of a more efficient motor designs achieve better speeds for any given amount of power usage.

    So yeah you can absolutely do it. But it's not a good idea for reasons that have nothing to do with the weight.

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  • [–] -1 points 1 year ago* (last edited 1 year ago)

    Yes, but is it possible to pedal and use regen breaking to recharge the battery when stationary? It does work like that in my car (plug-in hybrid) but I don't know if e-bikes are the same way.

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  • [–] 17 points 1 year ago

    The traditional method of pedaling uphill less strenuously is to drop to a lower gear. You might go slower, but I'd bet even on existing e-bikes with pedal assist, this is something that's already pretty reasonable now days.

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  • [–] 6 points 1 year ago (5 children)

    That's what gearing is for (you just go up the hill slower), but I can see the benefit to not being on the road.

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  • [–] 3 points 1 year ago (4 children)

    Sure, but there are limits. One needs a certain amount of forward speed to maintain balance easily, and there's a maximum speed that can be reasonably pedaled. If the hill is steep enough then in my experience reducing the gearing enough to make pedaling not too strenuous runs into the other two limits. If an e-bike can have a low battery topped off before the hill starts, then pedal-assist (at least) would take care of the need to lower the gear while going up it.

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  • [–] 6 points 1 year ago (1 child)

    If you need a minimum speed to maintain balance, how are you going to pedal while stationary?

    Better to have active regeneration, where you pedal a bit harder on flats to top up the battery for hills.

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  • [–] 3 points 1 year ago (1 child)

    One needs a certain amount of forward speed to maintain balance easily

    Not true. One just needs to practice static balance. It's a great skill to have so everyone should learn how to do it.

    Also you can use the lowest gear going almost a walking pace and climb up really steep hills. That's how we do it on MTBs. It also requires practice and good balance.

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  • [–] 297 points 1 year ago (4 children)

    mechanical engineering student

    Did not pay much attention in high school

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  • [–] 109 points 1 year ago (3 children)

    Look out for v2.0 which also features a sail on the front which you blow to go faster.

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  • [–] 46 points 1 year ago (2 children)

    Okay, but blowing on a sail to go faster is actually a thing. Mythbusters even stated that they did their experiment in the worst method (i.e., not using modern designs and methods), and still found that a fan on a sail could make it move. It's not free energy, but let's not ignore how cool sails are.

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  • [–] 35 points 1 year ago (1 child)

    This sounded very wrong to me, so I googled and apparently they had a setup where the reflected air from the sail caused a net flow in the opposite direction allowing them to move forwards. But that is less effective than just blowing the air straight backwards without a sail.

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  • [–] 78 points 1 year ago
    [–] 61 points 1 year ago (1 child)
  • [–] 121 points 1 year ago (5 children)

    Nice to get a moment to pull out a classic

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  • [–] 27 points 1 year ago* (2 children)

    As someone who sucks at physics, I'm convinced that Trollface has proposed so many solutions around the internet to provide free energy, but the capitalists are conspiring to sabotage him, just as they did to N.Tesla.

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  • [–] 58 points 1 year ago (4 children)

    Looks like it could even be AI style with all the emojis.

    Either way, thanks I hate it.

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  • [–] 51 points 1 year ago (7 children)

    This guy apparently doesn’t understand the first and second laws of thermodynamics. However, in his defense, this is sorta how regenerative braking works, but with less complexity.

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  • [–] 12 points 1 year ago (4 children)

    Most people don't. There is just no free lunch to ever be had.

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  • [–] 1 point 1 year ago (3 children)

    That explains why we exist right now (for free)

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  • [–] 51 points 1 year ago (8 children)

    Perpetual motion machine aside, where tf is bro going that the range of an ebike isn't enough, but the speed is

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  • [–] [S] 28 points 1 year ago (2 children)
  • [–] 7 points 1 year ago (4 children)

    Tbf it wouldn't be a perpetual motion machine because batteries -- even rechargeable ones -- have a limited capacity that reduces over time because they are a chemical reaction, the components of which degrade over time.

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  • [–] 47 points 1 year ago* (last edited 1 year ago) (1 child)

    Bro forgot to pay attention to thermodynamics.

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  • [–] 6 points 1 year ago

    I once had an exam question that began with the phrase "ignoring thermodynamic principles...". That question really threw me, it basically asked what would happen under XYZ situation if physics didn't exist. How the hell am I supposed to know that?

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  • [–] 44 points 1 year ago (3 children)

    Wow, excessive emojis and em-dashes... Not ai at all

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  • [–] 9 points 1 year ago (1 child)

    My LinkedIn feed is like 90+% AI at this point. I don't know why anyone bothers looking at the "content" on that website anymore. I only see it just incidentally on my way to the job listings and I am always shocked at how terrible it is

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  • [–] 2 points 1 year ago

    I was about to say, could this post possibly have any more emojis? Although, from my knowledge of existing MLM hunbots I unfortunately already know the answer lol

    Yeesh... the entire thing is so much secondhand embarrassment it makes me want to delete my entire profile just for the sake of it regardless of never using the actual site

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  • [–] 43 points 1 year ago (6 children)

    Mechanical engineering student huh? Good to know he didn't attend class on day 1 of dynamics

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  • [–] 21 points 1 year ago (3 children)

    Mechanical engineering student huh?

    1 week

    This is a normal trajectory for college freshmen. Get introduced to a bunch of basic ideas. Spitball and try to see how you can apply them. Start running into all kinds of caveats and engineering hurdles. Go back to class. Bother the RA. Maybe actually learn more about what you're trying to accomplish. Become a better engineer.

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  • [–] 3 points 1 year ago (1 child)

    Not believing you can create a perpetual motion machine should practically be an entry requirement. If you think you can you need to go back and do high school science again.

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  • [–] 7 points 1 year ago

    Nah, engineering students often forget and design perpetual motion machines. Usually, they remember why that is stupid and impossible before they post it publicly where I can haunt them forever.

    It should be a graduation requirement. It really should be...

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  • [–] 34 points 1 year ago (1 child)

    Why not cut out the middle man and directly charge battery 2 with battery 1? Switch and repeat.

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  • [–] 61 points 1 year ago (3 children)

    I had this exact idea... when I was 7. That was before I was introduced to newtonian physics.

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  • [–] 5 points 1 year ago (1 child)

    You were introduced to classical mechanics at age 8?

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  • [–] 2 points 1 year ago

    They can understand some basic concepts before you get into the math. Especially potential energy turning into heat, which children experience firsthand frequently. IMHO kids these days seem to understand energy more easily than we did; I think it's because of video games.

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  • [–] 21 points 1 year ago (2 children)

    This has to be a parody account right?

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  • [–] 3 points 1 year ago

    Either that, or he's not very smart, had a thought, poppet it into ChatGPT, and ChatGPT as it tends to do, affirmed his dumb idea, and he ended up asking it to make a Linkedin post for him on the idea.

    I've seen similar stuff from students who think they've cracked how something works, only to be incredibly wrong, because they only know half of what they need to, but don't know enough to understand how little they know. It's part of the journey of getting sorta-good at something though.

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  • [–] 19 points 1 year ago

    With this many emojis and em dashes, he's probably engagement farming using llm content, regardless of the thermodynamics gaps in logic

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  • [–] 18 points 1 year ago (1 child)

    Seems like satire to me. Pretty funny too.

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  • It's almost as if one object perpetually moves something that creates a form of motion perpetually to continuously move that first item. Like a continuous motion machine or perpetual movement apparatus. Something like that. I feel like my naming is close, though.

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  • [–] 32 points 1 year ago

    Newton? Never heard of him.

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  • [–] 15 points 1 year ago

    This guy is only telling us part of the truth. You actually need three batteries. The third battery is hooked up to a solar and wind generator. Only then can you achieve true energy independence.

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  • [–] 13 points 1 year ago

    Techbros rediscovering old principles, a tale as old as....well, since the tech industry.

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