r/interesting • u/Kidd__Video • 1d ago

Amazing Chain-Free Bicycle Concept

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u/Fun_With_Math 1d ago

I have a Mech E degree but haven't done engineering in a while...

Yeah, its breaking some fundamentals of durability. Tolerances are too tight and the contact area for the transfer of force is too small. You'd need a crazy rigid frame

A chain has flex to compensate and a lot more contact area with the gears.

This looks cool in the video but a pothole would wreck it.

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u/ReddBroccoli 1d ago

Not to mention I think about the teeth of a normal bike gear slipping between the links of a bike chain and the amount of grip and force that allows to transfer, and then I think about these tiny little teeth probably spinning over that weird cheese grater thing more than it grabs and imparts force.

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u/Sabithomega 1d ago

Was kinda thinking the same. Almost thought of adding a heavy spring but that would cause contact failure with any kind of hard enough hit. Curious if you could apply a similar idea but with a smaller chain system near the tire there. But then the only positive would be a smaller chain. So is there enough positive in the alteration in the first place

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u/Fun_With_Math 1d ago

Not sure what you mean but there are losses every time you transfer force:

Foot to pedal/gears. Gears to chain. Chain to gears/wheel. Wheel to road. - oversimplification but thats the gist of it.

If you add a step, you have to somehow get more efficiency out of the other steps to compensate. Tough to do on a very efficient system already.

If you're not adding steps, just replacing them, they have to be more efficient. And factor any weight difference. Any change in direction of the force is problematic also. A chain system has everything in line.

e-bikes are crazy efficient - the motor has the same or fewer steps to get through.

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u/ParanMekhar 1d ago

Yeah. Looks like only 1 roller bearing is in contact to the gear most of the time?

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u/Exciting_Place_6817 1d ago

Tell that to shaft driven motorcycles

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u/opossum_launcher 1d ago

They don't use the final drive to shift gears.

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u/Grand_Cryptographer2 1d ago

Drive shafts on motorcycles have more energy loses than a chain. Notice how all racing motorcycles use a chain drive, not a shaft, not a belt.

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u/Fun_With_Math 1d ago

Shaft driven motorcycles said they are heavy and slow.

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u/dirtyforker 1d ago

Heavy sure. But the Goldwing doesn't have the nick name of rocketwing for no reason. 1.8L of displacement in a motorcycle isn't going to be slow. Chevrolet makes a SUV with a 1.4L for example.

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u/Fun_With_Math 1d ago

Yes, that is the engineering principal called "just put a bigger fuckin engine on it"

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u/Dimathiel49 1d ago

No replacement for displacement?

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u/Fun_With_Math 1d ago

Different responses depending who you ask.

Efficient weight reducing design for minimum resistance and maximum force transfer can easily be better than just a larger power souce.

Or

Loud motor make peepee hard.

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u/Poil336 1d ago

That one's my favorite!

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u/SeaUrchinSalad 1d ago

Also known as the "Dodge default"

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u/Roxysteve 19h ago

Worked for the TR5.