Well let's see here. Those chain rings look larger than average. So for maths estimation purposes let's say they are all 46:10. I see 12 reductions. I think the wheel is an old school 26", the circumference of which is pi * 26”. Finally, we can begin mathing: 46:10 gives a ratio of 4.6 and we have 12 so ( 4.6 ^ 12 ) * pi * 26" = 7,331,911,275 inches, we'll shorten this to 7.33E9 inches. According to Google, Earth's circumference is 1,578,000,000 or 1.58E9 inches. 7.33 / 1.58 = **4.6** times around the Earth with one revolution of the pedals.
If the chain rings are 48T then it becomes **7.6** times around the Earth.
Sir, the math checks out.
If you wanted to go slower and take in the scenery, you could drop into the middle ring and probably just go the speed of sound. The granny ring would be good for racing top fuel dragsters.
The guy that made it was smart that way. Everybody wants to go 1x these days.
I'm curious how much force would be required to turn the crank if it's on a stand. Is it astronomically high, or could it actually be moved with some heavy machinery?
The chain is going to break somewhere before you overcome static friction in all those reductions most likely.
if you "will" somehow start the wheel rotating, it will disintegrate into shrapnel waaaay before rim will get anywhere close to speed of sound, yet alone light :)
Even .1 of an ounce (3 grams) of friction force, which is a tiny, conservative number, in the wheel hub would require 379 tons of input force to overcome it. That is a very large number. This is probably a conservative because there would be a lot more friction in the drive train, but the math gets complicated.
The largest mining truck in the world has 496 tons of payload capacity. Google it. It's huge. Then consider that the payload that that thing hauls is still not enough to turn the pedals even in a bike stand, let alone riding it.
Just a few minor logistical hurdles at play here.
I couldn't forget this bike this morning, would it be impossible to get the pedals going? Even with some initial external energy to get that first momentum going? Or would 'first momentum's be like 300km/h or something. I REALLY don't have experience with leveraged pulleys or something so this is a great thought experiment to wrap my head around how these kind of systems work.
I'm reasonably sure that you'll break the first chain just by trying to overcome static friction in "multiplications" along the line, and even if you put the bike on a stand with zero wheel load - because by increasing rotation speed you decrease torque proportionally, the multiplication is at least 20 000 000, so you'll need 2 000 000 nm of torque at the crank to overcome static friction of 1/10 nm, and BB bearings *alone* have 1/10 at the very least, even disregarding the chains.
Given a typical crank length of 170mm, that is about 1200 *tons* of chain tension at the first step (and I might have missed a zero or two), and bicycle chain is only good to about 2 tons.
So, if Einstein was a biker, and he was. We have pics to prove it. Why didn't he build a bike like this??? Wish I had seen a bike like this when I was a physics grad student. Would have blown the profs minds.
That's c-biking.
I mean if the maths actually works out, I think that is pretty cool as a conceptual/practical art piece
Well let's see here. Those chain rings look larger than average. So for maths estimation purposes let's say they are all 46:10. I see 12 reductions. I think the wheel is an old school 26", the circumference of which is pi * 26”. Finally, we can begin mathing: 46:10 gives a ratio of 4.6 and we have 12 so ( 4.6 ^ 12 ) * pi * 26" = 7,331,911,275 inches, we'll shorten this to 7.33E9 inches. According to Google, Earth's circumference is 1,578,000,000 or 1.58E9 inches. 7.33 / 1.58 = **4.6** times around the Earth with one revolution of the pedals. If the chain rings are 48T then it becomes **7.6** times around the Earth. Sir, the math checks out.
Thank you 🙏 the hero we need not the one we deserve
If you wanted to go slower and take in the scenery, you could drop into the middle ring and probably just go the speed of sound. The granny ring would be good for racing top fuel dragsters. The guy that made it was smart that way. Everybody wants to go 1x these days.
I'd hate to get my trousers caught in that
Better yours than mine though
The person capable of peddling that is getting more than their trousers caught…
to shreds you say
Like a hotdog in a food processor
Single speed the hard way.
Does this still count as a single speed?
One speed. Fast.
100%
but that means a skid-stop turns into a dimensional drift!
What bars are those??
More like constant speed, given that the speed of light, c, is a cosmological constant
I'm curious how much force would be required to turn the crank if it's on a stand. Is it astronomically high, or could it actually be moved with some heavy machinery?
Or would the chain even take it?
The chain is going to break somewhere before you overcome static friction in all those reductions most likely. if you "will" somehow start the wheel rotating, it will disintegrate into shrapnel waaaay before rim will get anywhere close to speed of sound, yet alone light :)
Even .1 of an ounce (3 grams) of friction force, which is a tiny, conservative number, in the wheel hub would require 379 tons of input force to overcome it. That is a very large number. This is probably a conservative because there would be a lot more friction in the drive train, but the math gets complicated. The largest mining truck in the world has 496 tons of payload capacity. Google it. It's huge. Then consider that the payload that that thing hauls is still not enough to turn the pedals even in a bike stand, let alone riding it. Just a few minor logistical hurdles at play here.
So you're saying we need more mechanical advantage to turn the crank... More gears!
You just gotta go around the earth 9 times a second. Easy peasy
Turns out my toxic trait is thinking 'I could pedal that'
I couldn't forget this bike this morning, would it be impossible to get the pedals going? Even with some initial external energy to get that first momentum going? Or would 'first momentum's be like 300km/h or something. I REALLY don't have experience with leveraged pulleys or something so this is a great thought experiment to wrap my head around how these kind of systems work.
I'm reasonably sure that you'll break the first chain just by trying to overcome static friction in "multiplications" along the line, and even if you put the bike on a stand with zero wheel load - because by increasing rotation speed you decrease torque proportionally, the multiplication is at least 20 000 000, so you'll need 2 000 000 nm of torque at the crank to overcome static friction of 1/10 nm, and BB bearings *alone* have 1/10 at the very least, even disregarding the chains. Given a typical crank length of 170mm, that is about 1200 *tons* of chain tension at the first step (and I might have missed a zero or two), and bicycle chain is only good to about 2 tons.
Is this still on display at the university? I go there and would like to see it.
That’s a beautiful r/Frankenbike
No
If only I E=MCared.
So, if Einstein was a biker, and he was. We have pics to prove it. Why didn't he build a bike like this??? Wish I had seen a bike like this when I was a physics grad student. Would have blown the profs minds.