4 ms·

FYI, reasons why air works really well as a suspension medium: * stiffness-to-weight is high and hysteresis low. That means a) easily adjusting the compliance

FYI, reasons why air works really well as a suspension medium: * stiffness-to-weight is high and hysteresis low. That means a) easily adjusting the compliance for different weights, b) excellent traction, since the "spring" isn't fighting its own inertia. * in normal operations, essentially unlimited durability, because there's no long-range order to break down. Let's see how these do after a million or so cycles. * when something does break your suspension, you're literally surrounded by the repair material. Again, let's see airless compete with that. The road is a very hostile surface. I've seen more than one well-meaning group try "ruggedised" tyres that became useless well before I'd even expect a puncture from a decent road tyre.

Valgrim 6y ago
You're absolutely right, but I'm still happy that someone created a full-size prototype of it outside the lab, and is testing it, tinkering with it and putting it out there so people can also try it and experiment with it. I don't know what this could lead to, maybe some sort of hybrid air-filled spring loaded undestructible bike tire, maybe it's going to end-up in a completely different application, such as wheelchairs or farming tractors or mining equipment.
- zbrozek 6y ago
  I'm also glad folks are tinkering. That said, bike tires are probably not where I would expect something like this to land. I would love these to replace the tires on things like utility carts, air compressors, etc that typically end up with solid tires. Those solid tires are awful, but pneumatic ones must be filled and that's annoying for infrequently used stuff.
  - analog31 6y ago
    Agreed. I happen to enjoy the hobby of tinkering with old bikes, so my bikes are typically a few decades behind the latest technology. So I can adopt a wait-and-see philosophy. But still I remember a cynical comment by my dad, maybe 40 years ago. They had just announced some new advanced material, and my dad said: "Mark my words, the first applications will be high end bikes and golf clubs." Also, improving on the bicycle is a very common capstone project for design students.
- mdip 6y ago
  Frankly, a tire that could maintain 80% of its performance under circumstances that a run-flat or standard tire would "blow-out" would be the difference between life and death on a motorcycle. Run-flat tires don't protect (enough) from blow-out, only puncture, which are handled well by most automotive/motorcycle tires, already. I realize the risk of blow-out is pretty low, but I've had it happen to me[0] -- regardless of how low a risk, I'd pay 4-5 times as much per tire on my motorcycle for being able to increase my chances of survival should that happen. [0] I probably don't need to mention this happened to me in a car since I'm not writing this from the afterlife.
  - ska 6y ago
    It's an interesting idea, but the fraction of motorcycle fatalities caused by blow-outs is so minuscule it's far more likely the decreased performance overall of this tire would cause far more. Unless you are assuming equivalent performance, which seems unlikely. Modern motorcycle tires are incredibly good, even (with appropriate ones) in rain.
    - _carbyau_ 6y ago
      Tyres are amazing anecdata: I got a rear puncture on my GSXR1000 while riding 100kmhr through the countryside. Straight was only slight issue, I noticed somethnig seemed a bit weird but road had minor undulations and I slowed a bit to 80. Slight turn though was quite wobbly so I stopped. Tyre gauge said less then 20psi, flat as it gets. That I could ride in a straight line with such stability was amazing testament to the tyre. I limped 30km to nearest town at 30kmhr or so. Slow but doable. Would I want to do this again? No, of course not. But that I could? Amazing. I agree that tyre performance > runflat as priority.
      - mdip 6y ago
        Holy cow - good to know. Were those run-flat tires? I'm about to replace the tyres[0] on mine in a month and I'm researching the safest options. [0] British, mate?
mdip 6y ago
I have always wondered why we accept the risk of "the thing holding you to the road just falling apart underneath you". I suspected it had to be really good at what it did when it worked but wasn't sure what that is. So, today I learned what a suspension medium and hysteresis is, but more importantly, why replacing "the tire" with something which eliminates the one safety issue would result in a number of other issues (some of which reduce safety in more serious ways than the risk of blow-out). Thanks for that!

Valgrim 6y ago

You're absolutely right, but I'm still happy that someone created a full-size prototype of it outside the lab, and is testing it, tinkering with it and putting it out there so people can also try it and experiment with it. I don't know what this could lead to, maybe some sort of hybrid air-filled spring loaded undestructible bike tire, maybe it's going to end-up in a completely different application, such as wheelchairs or farming tractors or mining equipment.

zbrozek 6y ago
I'm also glad folks are tinkering. That said, bike tires are probably not where I would expect something like this to land. I would love these to replace the tires on things like utility carts, air compressors, etc that typically end up with solid tires. Those solid tires are awful, but pneumatic ones must be filled and that's annoying for infrequently used stuff.
- analog31 6y ago
  Agreed. I happen to enjoy the hobby of tinkering with old bikes, so my bikes are typically a few decades behind the latest technology. So I can adopt a wait-and-see philosophy. But still I remember a cynical comment by my dad, maybe 40 years ago. They had just announced some new advanced material, and my dad said: "Mark my words, the first applications will be high end bikes and golf clubs." Also, improving on the bicycle is a very common capstone project for design students.
mdip 6y ago
Frankly, a tire that could maintain 80% of its performance under circumstances that a run-flat or standard tire would "blow-out" would be the difference between life and death on a motorcycle. Run-flat tires don't protect (enough) from blow-out, only puncture, which are handled well by most automotive/motorcycle tires, already. I realize the risk of blow-out is pretty low, but I've had it happen to me[0] -- regardless of how low a risk, I'd pay 4-5 times as much per tire on my motorcycle for being able to increase my chances of survival should that happen. [0] I probably don't need to mention this happened to me in a car since I'm not writing this from the afterlife.
- ska 6y ago
  It's an interesting idea, but the fraction of motorcycle fatalities caused by blow-outs is so minuscule it's far more likely the decreased performance overall of this tire would cause far more. Unless you are assuming equivalent performance, which seems unlikely. Modern motorcycle tires are incredibly good, even (with appropriate ones) in rain.
  - _carbyau_ 6y ago
    Tyres are amazing anecdata: I got a rear puncture on my GSXR1000 while riding 100kmhr through the countryside. Straight was only slight issue, I noticed somethnig seemed a bit weird but road had minor undulations and I slowed a bit to 80. Slight turn though was quite wobbly so I stopped. Tyre gauge said less then 20psi, flat as it gets. That I could ride in a straight line with such stability was amazing testament to the tyre. I limped 30km to nearest town at 30kmhr or so. Slow but doable. Would I want to do this again? No, of course not. But that I could? Amazing. I agree that tyre performance > runflat as priority.
    - mdip 6y ago
      Holy cow - good to know. Were those run-flat tires? I'm about to replace the tyres[0] on mine in a month and I'm researching the safest options. [0] British, mate?

mdip 6y ago

I have always wondered why we accept the risk of "the thing holding you to the road just falling apart underneath you". I suspected it had to be really good at what it did when it worked but wasn't sure what that is. So, today I learned what a suspension medium and hysteresis is, but more importantly, why replacing "the tire" with something which eliminates the one safety issue would result in a number of other issues (some of which reduce safety in more serious ways than the risk of blow-out). Thanks for that!