On Pneumatic Tires
scopeofwork.net
scopeofwork.net
I have witnessed bike tires where the bead/flange interlock wasn't perfect, and the inner tube was quickly swelling out between a small gap between rim and and bead until it burst with a bang that was louder than a gunshot. I once had a tire where the inner cloth was slightly damaged, and the tube was slowly creating a bulge in the tire over several days until it also burst. I found it amazing that all these counteracting forces still create something you can safely drive on, often for years, without problems.
What is the safest method to vandalize car tires?
It is genuinely amazing how reliable tires have become.
One hundred years ago, a car with two spare tires were not that unusual--tires were sufficiently unreliable that you might not manage a trip without _two_ flats, but tires improved, and now the only long-overland back-country adventurers carry two.
Their only reason for existing is to compensate for the historically poor observed reliability of tires. This has recently improved with TPMS mandates and better engineered tires.
The existence of spare tires has nothing to do with poor observed reliability. It is because of lack of 100% reliability. It's because when people get a flat, they don't want to be stuck and have to be towed. They want to be able to do something about it and get back on the road. All my flats have happened not because I lacked TPMS sensors but because something poked right through. Low tire pressure only accounts for 15% of flats. [1]
If you work for AAA, then sure, trying to convince people to get rid of their spares makes sense. But waiting around for AAA doesn't sound like a fun plan for me, especially when they won't be able to put a spare on for me, but will have to tow me somewhere.
[0]: https://cluballiance.aaa.com/public-affairs/press-release [1]: https://tiregrades.com/buying-guides/how-many-flat-tires-per...
Do you carry a spare battery, or spare keys? Because AAA says those are also among their highest reasons for service calls.
> All my flats have happened not because I lacked TPMS sensors but because something poked right through.
Simple punctures in tread can usually be fixed with an inflator kit, or a plug kit.
Impossible. A fair bit is 20km+ a day which is ~4000km/yr. That's in the order what an average tire is rated for (5-10Mm). Let's say you had tires 4 times as good, you still needed to change 5 times.
Those cars come with “run flat” tires, which supposedly allow you to drive a few miles without damaging the wheel when the tire is flat. After which, instead of patching the tire, it must be discarded. Quite the advancement.
The goal of performance oriented riders (for many, fixated might be the more accurate description) these days is to run the widest possible rim that will still hold their tire width of choice reasonably well. This has several reasons. One is that wind tunnel treats have repeatedly shown that there's an aerodynamic sweet spot where the rim is slightly wider than the tire, despite the increase in total frontal area for a given tire width (google "105 rule"), another is that riders want the suspension benefits of lower pressure but as little as possible of the downsides of the extra drag of wider tires, the extra mass of wider tires, increased danger of pinch flats and decreased lateral stability. Wider rims help with all those compromises.
Tubeless "just" allows for lower pressures without pinch flatting. The lower limit on pressure is to have enough to keep the bead seated, and not burping air. If you run lower than that, you've got to go tublar.
Yes, on rough (real world) road surfaces, rolling resistance is lower. (Ignoring aerodynamic drag of a larger tire profile.) On smooth surfaces like velodromes, skinny tires at stupid high pressures are faster. (I only bring this up because I race at a velodrome.)
Source: Among other things, I work at a bike shop part-time and have volunteered as a bike mechanic in the past.
This reads like someone just came back from outer space and was stunned by the complexity of all of the systems that got them there. I'm all for appreciating the little things, but we have to draw the line with overdramatization somewhere.
I was curious and investigated: it was invalidated because of Thomson’s patent as prior art 42 years earlier.
"The design process took in more than 10,000 hours of indoor testing, more than 5,000 hours of simulation, and more than 70 prototypes developed virtually, to eventually create 30 different specifications that were tested by nearly all the teams over more than 20,000 kilometres."
https://www.pirelli.com/tyres/en-ww/motorsport/f1/tyres
https://www.formula1.com/en/latest/article.the-beginners-gui...
To be somewhat pedantic, tires were in use for the nineteenth century and earlier. Tire generally refers to anything wrapped around a wheel making contact with the ground. Before pneumatic tires, there were iron tires. These were wrought iron rings placed around wooden wagon wheels.
Obviously the article is talking about pneumatic tires here, but I thought that I'd note that there are other, prior types.
Well... sometimes, other times I'd just prefer a good ol' walk to the bone shaking.
This sounds at best misleading. 2 wheeled carts must have been more common, they're still transport, supplying the same need as a 4 wheeled cart. It isn't as if there were a hand full of wheeled vehicles total.
There are exceptions to the above where people did ride in wagons. However they were rare as for most people walking was good. Many of the exceptions where to show off: I'm rich enough to have a wagon so I'm going to ride in it when you are looking (and if I think nobody is I'm getting out to walk).
It may not be difficult to conceive for much longer:
https://michelinmedia.com/michelin-uptis/
Granted, they are still tires, but just not pneumatic.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2759241/
Kal Penn has an 8-part series on the world economy, one episode of which highlights what a disaster if would be if this disease ever spread to Southeast Asia.
Alarmist? Maybe, I don't know. I know that there don't appear to be any direct flights from Rio to Bangkok, although I didn't look all that hard.
But then it was about tires.
Another way to look at this is to see the pitiful state of the rail network on the continent: the most efficient way to move goods and people over land, severely underused.
The article's author is very excited about tires, but it would be good to balance the stoke with the health and environmental impacts such mass usage of tires has. Rubber dust and microplastics polution in urban centers and along transport corridors contribute to a range of negative health impacts.
Not to mention, where do discarded tires end up: https://www.amusingplanet.com/2015/01/worlds-biggest-tire-gr...
This results in RR policies like precision scheduled rail (PSR), that tries to precisely utilize rail and crews to shuttle long trains across territory. PSR is only oriented to reduce RR costs. If a PSR train is late, every other train is delayed. PSR has also come alongside regularly running trains that are much longer than sidings, which makes it impossible for other trains to pass.
Everyone responds to incentives, and there are a couple of regulatory changes that could fix this.
1. Some level of regulation that penalizes RRs for delayed trains. PSR results in lower operating costs but the externality of delays isn't properly paid for by the RRs.
2. Increased technology investment like signalling improvements, positive train control and automatic couplers.
3. Some level of regulation of freight interchange along with timing and price regulations. You can send freight from an RR in Kansas to Louisianna, but you would have to go through two or more controlling RRs that would rather go point to point on their own network. I don't know what this regulation would look like.
4. Land value tax for tracks. Railroads are disincentivized from improving tracks, particularly with electrification. LVT would be hard to pass generally, but it makes a lot of sense to tax railroads less for electric tracks. Electrified tracks allow faster acceleration and electric locomotives are much more reliable than diesel locomotives.
The railroads in the US make immense profits (BNSF makes $6B in profits a year). There are severe regulatory capture problems that prevent these advancements.
I have read the Switzerland in particular has excellent freight rail that is speedy and used for smaller loads. I don't know their operating techniques that allow this.
Tossing the data in a spreadsheet and figuring percentages, the percentages of the total for those modes are: 64.6, 9.8, 4.3, 0.0, 2.8. 17.1, 0.2, and 1.2.
So 1.8 ratio of truck to non-truck, which is close enough to their claim that "In the United States, vehicles with tires carry twice as much freight as vehicles without them".
Personally, I'd exclude "Pipeline" since I wouldn't count that as a "vehicle". With that excluded the ratio of truck freight to other freight is 3.5 to 1.
1. it removes some need to use other vehicles, the same as any of the other transportation modes, and at quite high volume
2. it may be stationary, but still has “engines” in the form of pumping stations
3. it actually requires auxiliary vehicles for continued operation, in the form of employees traveling up and down the pipeline access roads in trucks or even with helicopters; this would be an interesting part of the calculation
4. there actually are movable parts of pipelines, called “pigs” in the transalaska pipeline: scrubbers that move up and down inside the pipeline, removing the solid material that accumulates on the interior walls
They aren’t just a long piece of cylindrical metal sitting there passively.
Thousands ships you can see in the US ports are all for import/export of goods.
The US has an inferior passenger rail network. It's freight rail network is fine.
In the US, freight within the country is 82% road, 12% rail, 5% water. In the EU it is 77% road, 17% rail, 6% water.
I wonder how these are actually counted? Suppose a manufacturer ships a ton of goods from their warehouse in Fresno to a retail chain in New York. Let's say that shipment goes by truck from Fresno to Los Angeles, where it then goes by train to Chicago, and there by water to Albany in New York, and finally from there to a New York warehouse owned the retail chain.
Does that count as 1 ton by road, rail, and water? Or is it going to have some kind of weighting by mileage?
If it is not weighted than road is going to be several times rail nearly everywhere, because there are a lot of things shipped locally which is almost always going to be cheaper and faster by truck than rail. On top of that most things that go by rail are also going to go part of the way by truck, since most things aren't both produced and consumed close to railroad stations and so it is mostly likely a truck that gets them to and/or from the train.
Also if it's fine why is most of the cargo moved by diesel semi?
Gasoline and Diesel are miracles, they carry vast sums of energy for little very weight.
Rail moves vast sums of cargo on trips over 600 miles, if the cargo is going less than 600 miles, odds are it's on a truck, but for expedited delivery operations, long haul single driver freight loads have mostly vanished, that business goes by train then truck for the last mile.
While I believe electricity is indeed the future for much of the world. I am not sure if its a slam dunk case with US rail lines today. Thinking at a high level for freight. Its possible that freight lines will go over leased tracks or tracks not otherwise not owned by the locomotive operator. So maybe it makes sense to only electrify specific lines, you not only introduce the upfront cost of electrifying which IIRC is a 2-3x (someone correct me if I am wrong) cost of just the existing tracks, you will also require different rail maintenance yards, require crews that know how to both operate and fix electric locomotives. Electricity is awesome but it won't be an easy sell to implement.
Locomotives will not be able to replace semi's. I am ignoring the fact they are run on diesel because I think this can and will change. The last mile will always be an issue. Additionally I believe most rail networks already run near capacity. Building more rail is a difficult task.
I don't know, but I'd guess its the same reason most cargo is moved that way in Europe too.
If you compare by ton-mileage, rail has a higher percent of the total in the US (27%) than the EU (20ish%) or China (16%) [1].
And while airplanes do have rubber tires, few people would say that the freight is carried on tires when the tires are only used for a tiny percentage of the trip. If pneumatic tires were never invented, airplanes could still exist, they'd land on non-pneumatic tires, skids, or some other method.
I think only someone looking for confusion would be confused by someone saying that rail freight and aircraft do not travel on rubber tires.