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“I can even tow 15 tons with it without any problems,” Beutler said, adding that he is planning a trip to the Baltic Sea in the summer. I have trouble envision

“I can even tow 15 tons with it without any problems,” Beutler said, adding that he is planning a trip to the Baltic Sea in the summer. I have trouble envisioning this. How could a ~2.5 ton human powered device tow a 15 ton load safely? My rather elementary understanding of physics would suggest to me that it can't stop quickly, or maybe not at all, if it's on an incline

kunwon1 4y ago
I've done some reading out of curiosity. My best theory is that there are trailer brakes that are actuated from the 'bicycle' - I think that would make this feasible. But I'm also reading things that make me think I just don't understand the physics of towing, so this might be much more feasible than I initially surmised
thatguy0900 4y ago
I think when you tow loads that big the attached trailer has its own separate brakes, right? The bike does have an engine to power an electrical system
userbinator 4y ago
A 35-speed transmission, with ridiculously low gearing, probably helps a lot. E.g. with a 1000:1 mechanical advantage, 15t becomes a very humanly manageable 0.015t (~33lb). That said, it won't have a very high top speed, and will spend a lot of time accelerating through the gears to get to it.
twobitshifter 4y ago
“Give me a lever long enough and a fulcrum on which to place it and I shall lift the world” - Archimedes. It’s like this guy took that idea and applied it to bicycle gears.
usrusr 4y ago
Braking quickly is only hard if you move quickly. If you don't, beaking quickly is trivial.
newaccount74 4y ago
The easiest way would be to use a transmission without a freehub. Then you would brake by pushing against the moving spinning pedals. As long as you are going slow, and you have a very low gear, it's not difficult. Trucks only need huge engines because they want to go fast.
- Sohcahtoa82 4y ago
  It's funny the way the physics works. I'm imagining a normal bicycle, but with a 1000:1 gear ratio. You could pull 15,000 lbs as if it was only 15 lbs. But then if you start going downhill, even hydraulic disc brakes would not have the stopping power to prevent the trailer for just pushing you down the hill. You would HAVE to have trailer brakes. But if your hub couldn't freewheel, then you could easily stop it with just one foot with the same amount of power it would take to pull the trailer up the hill.
  - newaccount74 4y ago
    One thing I forgot about is friction. If the trailer is too heavy then it's going to push the bike down if the grade is too steep. That's why train tracks are always very flat -- the wagons are much heavier than the locomotive.
_yb2s 4y ago
You are right- stopping on a very steep grade would be nearly impossible without brakes on the trailer also. But realistically, how steep of a grade are you going to want to tow 15 tons up with pedal power? You're not going to be moving much at all. Towing that much on level ground would be a separate stunt from doing his trip to the baltic. Given his top speeds are likely to be close to slug ground speed levels and on perfectly level ground, braking with just the tow vehicle would be fine still.
sidewndr46 4y ago
Towing large amounts of weight doesn't work the way you'd think. As long as we're talking about something on wheels that are on pavement a normal car can tow 30,000 lbs or so. A Ford pickup towed a Boeing airplane a while back in some weird stunt. In strongmen competitions just a person with a rope can pull a train car. Towing something at high speed is a question of aerodynamics. Towing something offroad in mud is usually a question of getting enough traction without your tires just digging a hole.

kunwon1 4y ago

I've done some reading out of curiosity. My best theory is that there are trailer brakes that are actuated from the 'bicycle' - I think that would make this feasible. But I'm also reading things that make me think I just don't understand the physics of towing, so this might be much more feasible than I initially surmised

thatguy0900 4y ago

I think when you tow loads that big the attached trailer has its own separate brakes, right? The bike does have an engine to power an electrical system

userbinator 4y ago

A 35-speed transmission, with ridiculously low gearing, probably helps a lot. E.g. with a 1000:1 mechanical advantage, 15t becomes a very humanly manageable 0.015t (~33lb). That said, it won't have a very high top speed, and will spend a lot of time accelerating through the gears to get to it.

twobitshifter 4y ago

“Give me a lever long enough and a fulcrum on which to place it and I shall lift the world” - Archimedes. It’s like this guy took that idea and applied it to bicycle gears.

usrusr 4y ago

Braking quickly is only hard if you move quickly. If you don't, beaking quickly is trivial.

newaccount74 4y ago

The easiest way would be to use a transmission without a freehub. Then you would brake by pushing against the moving spinning pedals. As long as you are going slow, and you have a very low gear, it's not difficult. Trucks only need huge engines because they want to go fast.

Sohcahtoa82 4y ago
It's funny the way the physics works. I'm imagining a normal bicycle, but with a 1000:1 gear ratio. You could pull 15,000 lbs as if it was only 15 lbs. But then if you start going downhill, even hydraulic disc brakes would not have the stopping power to prevent the trailer for just pushing you down the hill. You would HAVE to have trailer brakes. But if your hub couldn't freewheel, then you could easily stop it with just one foot with the same amount of power it would take to pull the trailer up the hill.
- newaccount74 4y ago
  One thing I forgot about is friction. If the trailer is too heavy then it's going to push the bike down if the grade is too steep. That's why train tracks are always very flat -- the wagons are much heavier than the locomotive.

_yb2s 4y ago

You are right- stopping on a very steep grade would be nearly impossible without brakes on the trailer also. But realistically, how steep of a grade are you going to want to tow 15 tons up with pedal power? You're not going to be moving much at all. Towing that much on level ground would be a separate stunt from doing his trip to the baltic. Given his top speeds are likely to be close to slug ground speed levels and on perfectly level ground, braking with just the tow vehicle would be fine still.

sidewndr46 4y ago

Towing large amounts of weight doesn't work the way you'd think. As long as we're talking about something on wheels that are on pavement a normal car can tow 30,000 lbs or so. A Ford pickup towed a Boeing airplane a while back in some weird stunt. In strongmen competitions just a person with a rope can pull a train car. Towing something at high speed is a question of aerodynamics. Towing something offroad in mud is usually a question of getting enough traction without your tires just digging a hole.