mechanical engineering student
Did not pay much attention in high school
Look out for v2.0 which also features a sail on the front which you blow to go faster.
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.
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.
Look for the sail car video from Veritasium. With a chain drive you can out run the wind using the principles of sail propulsion.
When the battery runs out, you pull over and “pedal” to recharge the battery, then you’re good to go again!
now that is genius!
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.
Assisted modes already exist, and regenerative braking already exist
But this joke is more funny :)
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.
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.
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.
Not if you have a hub motor. Those don’t interact with the gear system at all.
Yup, which is also why they’re really hard to pedal if the battery dies.
It needs a direct drive which is more weight than the other systems
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.
Freewheel hub would prevent it.
You would need to put the freewheel between the motor and the pedals, and have an always-spinning chain/shaft
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.
You can find YouTube videos of people experimenting with flywheel-based regenerative braking. They’re completely impractical but pretty funny to see.
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.
It’s like 3-15% energy reclaimed, not efficient
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.
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.
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.
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.
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.
Kickstand, holding a fence, etc. That active Regen thing sounds great, if I buy one of these I’ll make sure it can do it.
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.
Ah, that would be a nice skill. I might even be better equipped for it now than when I was young because I’ve gotten into roller skating and improved my balance that way.
Gears
Incredible comment.
Nice to get a moment to pull out a classic
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.
This is satire… right? I hope it is
Yet another “engineering student” who hasn’t learned his Newtonian physics yet. Which I’m pretty sure is covered in grade school, but you never know.
I’d go with second law of thermodynamics, but whatever.
The amount of emojis scream AI generated.
LinkedIn has been shit posting goldmine lately.
I had this exact idea… when I was 7. That was before I was introduced to newtonian physics.
It’s a good idea, even if it can be ruled out. That person should offer more ideas. All of those Newtonian physics people never seem to offer up ideas.
You were introduced to classical mechanics at age 8?
They could’ve heard of Newtonian physics at any point between when they had the idea and now
Sort of.
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.
I have never seen the Arabic language translation of this meme but I immediately understood it from having seen the English version.
Looks like it could even be AI style with all the emojis.
Either way, thanks I hate it.
Yea I’m 99% sure it was drafted by AI
There have been idiots before AI. People should still receive
blamecredit for their idiot ideas, instead of blaming AI for every stupid post.
Likely not only drafted with AI, but only pursued because he entered the idea into ChatGPT and asked “is this a good idea?,” and uncritically took ChatGPT’s enthusiastic support as vindication.
Perpetual motion machine aside, where tf is bro going that the range of an ebike isn’t enough, but the speed is
The Future
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.
As well as inevitable failure at the weakest friction point.
Tldr, thermodynamics
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.
Most people don’t. There is just no free lunch to ever be had.
That explains why we exist right now (for free)
A very, very unfunny joke.
Regenerative braking was my first thought.
It’s impressive that he figured out how to create a post though, considering room temp iq (during the winter in a commie block apartment, in celsius)
deleted by creator
Mechanical engineering student huh? Good to know he didn’t attend class on day 1 of dynamics
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.
Yeah but you missed rule 1: Don’t post your gobshite ideas on LinkedIn.
Bro forgot to pay attention to thermodynamics.
Wow, excessive emojis and em-dashes… Not ai at all
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
with uBlock Origin you can just filter the feed
www.linkedin.com##[aria-label^=“Main Feed”]
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
Newton? Never heard of him.
This is dumb as shit ofc, but it gave me an idea that’s probably nearly equally dumb as shit:
Regular bicycle, but with an extra gear that can selectively connect to the chain or wheel or w/e, that’s connected to a coil torsion spring on a kind of ratchet release.
Basically you flip the switch when it’s a good time to rob some energy like when you’re on level ground or going down hill. That energy makes you a tad less efficient (but you don’t care cuz it’s level or downhill), and uses that energy to wind up the coil torsion spring up until a max amount of torque is stored.
Fast forward a bit: now you’re approaching an incline, so you flip the switch the other direction and that torsion spring regurgitates that energy back into forward motion, giving you a nice forward burst when going up a hill.
Not free energy by any stretch, but a strategic use of what you’re already spending.
Feel free to explain why this is a horrible idea - I’m about as far from a physicist as it gets.
That’s effectively what hybrid cars do.
Essentially regenerative braking. Should work, though the question is how coat effective.
F1 has been using this principle for years
Dynamo lights work off a similar principle. It extracts energy from pedaling or the wheels spinning to power lights on the bike. You can feel the drag and it’s probably about 5w of power. Really not a whole lot. About the same energy you’d save from wearing smooth socks or cleaning the chain for some perspective.
The extra weight required to implement a solution like yours would probably rob the rider of any gains. But in a very theoretical sense it could work if the material weighed an insignificant amount.
Why flip a switch when you can just let the bike sense if it is going up or down hill?
Would make hilly terrain a much smoother ride.
Then again, if you do all that electrical, you already just have an electric bike. Which is even more versatile on flat ground.
