this post was submitted on 07 Apr 2025
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[โ€“] [email protected] 1 points 8 hours ago

Coming soon to FortNite?

[โ€“] [email protected] 12 points 21 hours ago* (last edited 21 hours ago) (4 children)

This is the kind of silly design I was thinking of 25 years ago as I was cursing the headwind on the bikepath on my way home. Not the solar panel roof, but a straight up windmill mounted on my bike ๐Ÿ˜….

Doesn't it generate too much drag to be of any use?

[โ€“] [email protected] 6 points 16 hours ago

Yeah the turbine on top does not make sense while driving. It could be something used while it is parked.

Yes, there are contraptions that can extract energy from downwind or upwind vehicles. This is not one of those. On any decent road speed that thing will drag like hell.

[โ€“] [email protected] 4 points 16 hours ago

I think I've worked it out, after some discussion in another comment thread.

This contraption probably has a high centre of gravity and would tip over backwards if you accelerate too fast. They probably worked out a wind turbine on the top spreads the acceleration force and reduces this problem. The turbine is not for generating power, it has a motor and is used to give some thrust to the top.

[โ€“] [email protected] 2 points 16 hours ago (1 children)

you can gain energy while moving upwind, it makes more sense if you think about how boats can do a zig-zag to sail upwind (tacking).

https://www.youtube.com/watch?v=u5InZ6iknUM

[โ€“] [email protected] 1 points 9 hours ago* (last edited 9 hours ago)

Although the video they refer to in your link is about going faster in the direction of the wind, there is a cool explanation about tacking in it. Both great videos btw.

[โ€“] [email protected] 3 points 20 hours ago* (last edited 19 hours ago)

I would think the drag is considerable.

I would also worry about stability in a strong side wind.

As a result, I would not like to ride the 2-wheeled version in strong side wind. The 3-wheeled version looks OK, but also suffers from drag.

Besides, to generate power from wind while parking, you would have to choose your parking direction. But you can't always choose the parking direction - location dictates it often. Toppling over while parked would be a definite thing to expect with this setup.

That kind of kit on two-wheeled vehicle looks severely half-assed. They should have thought more steps ahead.

[โ€“] [email protected] 10 points 22 hours ago (2 children)

Sorry can someone explain how the turbines work? Is the turbine pulling the motorbike forward or is it there to generate power?

The bike has an electric motor so the turbine seems unnecessary. But if the motor is pulling it forward then it's fighting the turbine so it's wasting energy (it's not some perpetual motion device).

Are the solar and turbines there so you park up and the bike charges while you're shopping?

I just can't understand why the addition of turbines is helpful here.

[โ€“] [email protected] 2 points 16 hours ago (1 children)

you can actually gain energy while moving upwind, it's counterintuitive but the existence of tacking in sailing (doing a zig-zag upwind) makes it a bit easier to internalize for me.

https://www.youtube.com/watch?v=u5InZ6iknUM

[โ€“] [email protected] 1 points 8 hours ago

That's a little bit different.

In your case, the wind is blowing and the craft is getting energy from it.

I was referring to the energy coming from the motor pushing you through the air and then trying to claim some energy from the wind you created by pushing yourself through the air with the motor.

If there is wind blowing you could in theory get some energy from it, but the thing about sailboats is there is a constant need to adjust the sail when you turn. A turbine on the front isn't going to be angled correctly whichever direction you turn.

But I think I worked out the reason for the turbine. It's powered by the battery (it's not intended to charge the battery) and I think is there to pull the top of the contraption forward so it doesn't fall over when accelerating.

[โ€“] [email protected] 1 points 20 hours ago (1 children)
[โ€“] [email protected] 5 points 20 hours ago* (last edited 20 hours ago) (1 children)

But it doesn't help. If you are travelling forward under the force of the motor using the electricity, then using the wind from that forward motion to generate electricity with the turbine will produce less electricity than the extra energy needed to propel you forward when you have a turbine on the top creating air resistance. If you could use a motor to travel forward and use a wind turbine to capture energy from that motion in a way that produces more power than you put in, well that would be a source of infinite energy. It violates the law of conservation of energy.

The only thing I can think of is that it generates electricity from the wind when you are not moving. But considering the size of it, I can't imagine it's worth it to generate that tiny amount of electricity when stopped to then have that increased drag when moving causing you to use more power.

[โ€“] [email protected] 2 points 18 hours ago (1 children)

The only way I can see it being sensible is if it's easily detachable when you're actually riding it and the idea is for it to charge the bike with the wind when you're not riding

[โ€“] [email protected] 4 points 17 hours ago* (last edited 17 hours ago) (1 children)

I think I've worked it out. I think it's not generating power from wind, it's additional thrust. It seems pointless since they could have put a bigger motor in?

The article in the OP links this source, but it only has an info sheet. It's in Chinese but it's just a list of specs. But there is one small hint. The top table has (assuming machine-translation is correct):

Wind-Powered Range โ‰ฅ50km

The bottom table has:

Wind Power Motor 300W/72V (Permanent Magnet Brushless)

So I'm convinced the intention here is that the motor spins the wind turbine to pull the bike forward.

It doesn't seem to make sense from a thrust point of view, so I have a new theory - this contraption probably has a high centre of gravity and would tip over backwards if you accelerate too fast. They probably worked out a wind turbine on the top spreads the acceleration force and reduces this problem.

[โ€“] [email protected] 3 points 16 hours ago

A lot of electric motorcycles have limiters on how fast you can turn the throttle to prevent riders who are used to ICE motors from throwing themselves off the bike with a massive wheelie due to the instant torque. I can't believe none of them thought to counteract the rotational force with an above-centre-of-mass propellor. Ingenious!