4 ms·

I believe tire dust is about 40% plastics so add that the microplastics bin + the other stuff off of it.

benterix 2y ago
Brake dust is comparable to tyre dust BTW: https://www.sciencedirect.com/science/article/pii/S0269749123008321 https://www.sciencedirect.com/science/article/pii/S026974912...
- ZeroGravitas 2y ago
  Drum brakes can capture this dust for safe disposal, but are seen as old fashioned and for poor people.
  - more_corn 2y ago
    This is not true. Drum brakes are not sealed.
    - sokoloff 2y ago
      They are not sealed perfectly, but every drum that I’ve removed had a pile of shoe dust that was a very significant fraction of the original mass of the shoe friction material worn. I’d estimate that 50% or more of the material ends up at the workshop instead of along the roadside.
  - toast0 2y ago
    The interwebs say that disc brakes are better able to dissipate heat, provide more consistent braking performance, and generally reduce stopping distance. Drum brakes are old fashioned, most US vehicles switched to at least disc brakes in the front in the late 1970s and early 80s. Drums in the rear make the parking brake simple, and rear brake performance is less important as more braking force comes from the front. I don't know about being "for poor people", except that poor people may be more likely to have older vehicles, but I don't know that that extends to using vehicles that old, most vehicles with drums are 40+ years old at this point, and keeping something that old alive starts to get spendy because parts are trickier to find, and it costs time or money or both to adapt parts from other vehicles (like upgrading to disc brakes from a newer car)
    - ZeroGravitas 2y ago
      Some modern EVs already use drum brakes on the rear. Since they have regenerative breaking you don't get brake fade on long downhills. New EU regulations are coming in to limit brake dust and so people are looking at them again. And other ideas, like mercedes has a prototype that puts the brake inside the motor.
    - sokoloff 2y ago
      Note that some cars have parking/emergency brakes as drum brakes in the center of a rotor that provides disc brakes for the service (“normal”) brakes, so you can still get disc braking performance with the parking brake cable mechanism. Drum brakes are also slightly more efficient, with the shoes exhibiting less drag when not applied, which is important on small battery EVs. (They are worse for high-energy or repeated braking, but better in cruise.)
- more_corn 2y ago
  Regenerative braking converts 90% of braking from pad on rotor to running an electrical generator.
  - observationist 2y ago
    If it costs more to replace degraded magnets or motors every million miles compared to brake pads, it will raise the cost of transportation. It's also not feasible to use in ICE vehicles - once you've filled your battery, the only place for that energy to go is heat. It's not just a tradeoff between ICE and electric, or drum vs pad brakes, or rubber additive A vs B. It's a complex ecosystem upon which people's lives and livelihoods are dependent, with unpredictable and chaotic relationships. The naive view is to simply replace the apparently "bad" material in tire dust, but if that raises the cost of transportation, food prices go up, quality of life goes down, nutrition suffers, and possible downstream effects end up causing more harm than good. This isn't to say we shouldn't bother, just that a superficial approach targeted at a single issue could end up doing a lot of unintended damage, and there's no bounded scale of harm. Trying to reduce cancer rates by .0001% might end up reducing average lifespan by a decade, or some other consequence that's orders of magnitude more impactful than the thing being "fixed". We live in a complex and dynamic system; the supply chain sits at the base of it all. We benefit from the economies of scale serving the supply chain, so we have access to cheap vehicles, efficient and cheap long haul trucks give us access to food and products. Tinker with that too aggressively and people can die. The best route toward action on things like this are cultural - educate individuals and make alternatives available. People can adjust at their own convenience, and the trend of markets will resolve on a balance between health and safety risks and convenience. You could simply ban private cars, and presumably 35k fewer deaths would occur each year in the US, and we could work on monolithic solutions to things like brake dust and tire dust. We've decided that our collective quality of life and the benefits conferred us by allowing private transportation far outweigh the harms. We need to find where the balance is between the potential harms of these dusts and how much we're willing to give up in mitigating those harms. Anyway - it's not a trivial exercise, it's a microcosm of the global economy, with surprising complexity and dependencies at every level.
    - 2y ago
taeric 2y ago
Last time this came up, the story was about plastics in the ocean, and following the links on the story was specifically challenging how much tires contribute. Such that I'd love to see any more sources on this. To be clear, it is a plausible sounding claim. I'm just growing nervous accepting plausible things.

Brake dust is comparable to tyre dust BTW: https://www.sciencedirect.com/science/article/pii/S0269749123008321 https://www.sciencedirect.com/science/article/pii/S026974912...

ZeroGravitas 2y ago
Drum brakes can capture this dust for safe disposal, but are seen as old fashioned and for poor people.
- more_corn 2y ago
  This is not true. Drum brakes are not sealed.
  - sokoloff 2y ago
    They are not sealed perfectly, but every drum that I’ve removed had a pile of shoe dust that was a very significant fraction of the original mass of the shoe friction material worn. I’d estimate that 50% or more of the material ends up at the workshop instead of along the roadside.
- toast0 2y ago
  The interwebs say that disc brakes are better able to dissipate heat, provide more consistent braking performance, and generally reduce stopping distance. Drum brakes are old fashioned, most US vehicles switched to at least disc brakes in the front in the late 1970s and early 80s. Drums in the rear make the parking brake simple, and rear brake performance is less important as more braking force comes from the front. I don't know about being "for poor people", except that poor people may be more likely to have older vehicles, but I don't know that that extends to using vehicles that old, most vehicles with drums are 40+ years old at this point, and keeping something that old alive starts to get spendy because parts are trickier to find, and it costs time or money or both to adapt parts from other vehicles (like upgrading to disc brakes from a newer car)
  - ZeroGravitas 2y ago
    Some modern EVs already use drum brakes on the rear. Since they have regenerative breaking you don't get brake fade on long downhills. New EU regulations are coming in to limit brake dust and so people are looking at them again. And other ideas, like mercedes has a prototype that puts the brake inside the motor.
  - sokoloff 2y ago
    Note that some cars have parking/emergency brakes as drum brakes in the center of a rotor that provides disc brakes for the service (“normal”) brakes, so you can still get disc braking performance with the parking brake cable mechanism. Drum brakes are also slightly more efficient, with the shoes exhibiting less drag when not applied, which is important on small battery EVs. (They are worse for high-energy or repeated braking, but better in cruise.)
more_corn 2y ago
Regenerative braking converts 90% of braking from pad on rotor to running an electrical generator.
- observationist 2y ago
  If it costs more to replace degraded magnets or motors every million miles compared to brake pads, it will raise the cost of transportation. It's also not feasible to use in ICE vehicles - once you've filled your battery, the only place for that energy to go is heat. It's not just a tradeoff between ICE and electric, or drum vs pad brakes, or rubber additive A vs B. It's a complex ecosystem upon which people's lives and livelihoods are dependent, with unpredictable and chaotic relationships. The naive view is to simply replace the apparently "bad" material in tire dust, but if that raises the cost of transportation, food prices go up, quality of life goes down, nutrition suffers, and possible downstream effects end up causing more harm than good. This isn't to say we shouldn't bother, just that a superficial approach targeted at a single issue could end up doing a lot of unintended damage, and there's no bounded scale of harm. Trying to reduce cancer rates by .0001% might end up reducing average lifespan by a decade, or some other consequence that's orders of magnitude more impactful than the thing being "fixed". We live in a complex and dynamic system; the supply chain sits at the base of it all. We benefit from the economies of scale serving the supply chain, so we have access to cheap vehicles, efficient and cheap long haul trucks give us access to food and products. Tinker with that too aggressively and people can die. The best route toward action on things like this are cultural - educate individuals and make alternatives available. People can adjust at their own convenience, and the trend of markets will resolve on a balance between health and safety risks and convenience. You could simply ban private cars, and presumably 35k fewer deaths would occur each year in the US, and we could work on monolithic solutions to things like brake dust and tire dust. We've decided that our collective quality of life and the benefits conferred us by allowing private transportation far outweigh the harms. We need to find where the balance is between the potential harms of these dusts and how much we're willing to give up in mitigating those harms. Anyway - it's not a trivial exercise, it's a microcosm of the global economy, with surprising complexity and dependencies at every level.
  - 2y ago

taeric 2y ago

Last time this came up, the story was about plastics in the ocean, and following the links on the story was specifically challenging how much tires contribute. Such that I'd love to see any more sources on this. To be clear, it is a plausible sounding claim. I'm just growing nervous accepting plausible things.