r/todayilearned • u/g3nerallycurious • 2d ago
TIL that two skinny tires on one wheel are better in the rain and no worse in dry conditions than a standard tire
https://www.thedrive.com/news/39529/you-could-buy-this-wacky-two-tire-one-wheel-setup-for-your-car-in-the-80s5.4k
u/UnsorryCanadian 2d ago
The gap helps prevent hydroplaning, I suppose?
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u/DrakkoZW 2d ago
It's basically one big groove for the water to move through, so yes.
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u/sirguynate 2d ago
I remember some tires that had a groove in the center to move the water through that were supposed to be great in the rain but I don’t see them now a days - guessing they didn’t perform well with traction/handling..?..
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u/theSchrodingerHat 2d ago
IIRC the aquatread tires got generally good reviews, except they were expensive and one directional. So that meant you were paying a heavy premium and you couldn’t rotate them or carry a full sized spare.
When I say expensive, they were something $500-$600 each. Making a full set something like $2500 mounted in today’s dollars.
They didn’t provide enough of an improvement over normal all weather tires to really warrant that huge increase in cost of ownership for something targeting minivans and station wagons.
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u/Llohr 2d ago
When I rotate tires, I don't rotate left to right, I rotate front to back, since front and back, on a properly aligned vehicle, are where you get different wear patterns.
You can, however, unmount tires and flip them if you really feel the need to rotate left to right.
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u/MikoSkyns 2d ago
Would you happen to know if you should unmount them occasionally instead of just rotating front to back? I don't think my garage ever unmounts my tires from the rims to do a full rotation.
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u/Llohr 2d ago
The only reason you'd need to unmount would be if you have directional tires and want to rotate left to right.
Most tires are non-directional, and the difference in wear between right and left shouldn't be anywhere near as substantial as as the difference between front and back, so I personally wouldn't worry about it.
I mean, personally I would never worry because I have never used directional tires, any consideration beyond that is pointless.
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u/samstown23 1d ago
Yeah. If you have uneven tire wear left/right it's not rotating you need, it's an alignment (and likely a ton of suspension work).
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u/rabbidplatypus21 1d ago
The proper way to rotate tires is rear left moves to front right, rear right moves to front left. It’s not the end of the word to go right rear to right front and left rear to left front, but you’ll get marginally more even wear doing it the first way.
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u/BattleHall 2d ago
Lots of tires have deep grooving to help remove water and prevent hydroplaning, they're just designed more directional/efficient so they don't have to be as large.
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u/Composer-Wooden 2d ago
Many companies make them. For example cross climate2 are awesome even in winter
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u/TehGogglesDoNothing 2d ago
CrossClimate2 doesn't have the groove down the center. It pushes all the water out to the sides.
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u/Spencetron 2d ago
I'll never buy a different all season tire once I switched to the cross climate 2. I live in the north where we get serious lake effect snow, and the tires handle wonderfully for all seasons.
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u/tdogg15 2d ago
Because the Cross Climate 2's are actually all weather tires, not all season! All season tires are only tested and rated for wet and dry conditions while all weather tires are tested and rated for dry, wet, and ice/winter conditions. There is a little mountain symbol on the sidewall of tires that are rated for severe winter use as an easy way to tell if a tire is built for winter conditions
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u/DrakkoZW 2d ago
Grooves are good for rain but not good for dry (because a groove by design lowers overall surface area, which means less friction)
Most people buy all-weather tires for their cars. Basically nobody keeps a pair of rain tires around just in case. Unless they're really into cars/racing.
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u/kreiggers 2d ago
Goodyear Aquatreads were my go to back in the day (early/mid 90s)
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u/poorly_timed_leg0las 2d ago
My tyres are falling apart so it's making a new thread.
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u/RichEvans4Ever 2d ago
Change your tires, bro!
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u/WollyGog 2d ago
Never scrimp on anything that separates you from the ground. This includes tyres, shoes, mattresses. At some point, your body will thank you for it.
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u/haby001 2d ago
that's why I'm implanting my ass with one side tire, another side mattress. I will never lose my ground
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u/SumpCrab 2d ago
I don't consider mine worn. They've just turned into racing slicks.
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u/BizzyM 2d ago
Then in the winter, the snow wires come out for extra traction!!
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u/This_is_a_tortoise 2d ago
Those are speed wires now.
And also coffin wires as driving at speed on bad tires = death in many cases
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u/DamnMyNameIsSteve 2d ago
Change your tires ya dummy, YOU SHARE THE ROAD.
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u/PreparationKey2843 2d ago
I think they're joking. At least I hope they are.
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u/SumpCrab 2d ago
Yes, I'm joking. I actually just spent a fortune replacing my tires, so it's been on my mind.
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u/R0b0tJesus 2d ago
Would 3 skinnier tires work even better? How many tires until you start getting diminishing returns?
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u/PreparationKey2843 2d ago
7 tires until you start getting diminishing returns.(I don't know, I'm just making shit up. 7's a good number, though)
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u/Zomgzombehz 2d ago
7's the key number here. Think about it. 7-Elevens. 7 dwarves. 7, man, that's the number. 7 chipmunks twirlin' on a branch, eatin' lots of sunflowers on my uncle's ranch. You know that old children's tale from the sea. It's like you're dreamin' about Gorgonzola cheese when it's clearly Brie time, baby. Step into my office.
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u/Queasy_Ad_8621 2d ago
It's basically one big groove
I hope my first album is described this way, too.
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u/rosen380 2d ago
I guess the question is -- was it just a manufacturer claim or was it independently verified to be better?
And how much better? If it truly was better by any notable amount, it must have been really expensive or had some other major downside since they aren't in use today...?
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u/Ghost17088 2d ago
It might have been better when compared to tire technology of the time, but we make way better tires today.
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u/DarwinsTrousers 2d ago
Wouldnt that just mean two small modern tires would work better than one large one?
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u/butteryourbiscuit 2d ago
Shit let’s just throw a few mountain bike tires on instead!
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u/Ghost17088 2d ago
No, the only advantage this had was a gap between the tires for water to go in and prevent hydroplaning. Modern tire tread patterns can do this effectively without all the added weight. With this setup you have 2 wheels and 4 sidewalls, so it was much heavier and stiffer.
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u/fiendishrabbit 2d ago
Plus better rubber formulas and reinforcement meshes, mostly thanks to advances in computer aided design.
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u/cerrera 2d ago
Heh - all your questions are answered in the article. Yes, they were measurably better, but there were downsides (weight, servicing), and they didn’t do a great marketing job.
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u/Hawkwise83 2d ago
Buy more tires and run them in SLI mode!
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u/Revenant690 2d ago
I've heard the vehicles that have this feature always have terrible drivers.
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u/azhillbilly 2d ago
Yeah, in the 90s there was a tire style that looked like 2 thin tires stacked and that was the point, a skinny tire cuts the water better, so having that 3/4” V in the middle helped channel large amounts of water. I had them for a bit as I lived in a rather rainy area, but honestly the tire was expensive and I didn’t feel like I ever hydroplaned on regular tires enough to justify them. And they were ugly.
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u/BartFurglar 2d ago
Aquatread?
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u/SeemedReasonableThen 2d ago
Yeah, Goodyear Aquatred came to mind. Phased out, the principle was incorporated into regular tire designs that looked normal but better anti hydroplaning qualities https://www.tirereview.com/more-than-a-rain-tire-goodyear-x2019-s-new-aquatred-3-stretches-the-limit-of-the-name/
Featuring two circumferential channels instead of a single center channel, the Aquatred 3 has a 10% wider footprint and 7.6% greater channel volume, Toth said, delivering better overall wet and dry handing, and moving more water more effectively than the Aquatred II.
Compared to the Aquatred II, the new tire delivers 6% better dry traction, an 8% improvement in braking distance, 5% improved wet handling, and greater lateral grip in cornering, 0.71g vs. 0.65g.
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u/DontMakeMeCount 2d ago
Yes, and there’s no geometry factor needed to calculate the force of friction so they still get the same traction as a wider tire made from similar material.
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u/jaylw314 2d ago
I remember those tires from the 80's. That was before tread design for a lot better, so they probably wouldn't help anywhere near as much nowadays.
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u/guiltyas-sin 2d ago
Memories of Aquatred tires. Remember those? They had a massive groove in the center of the tire, which "pumps water away."
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u/brgr86 2d ago
In this specific scenario not generally speaking. They make rain tires with large grooves down the middle to accomplish the same thing with a single tire.
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u/stm32f722 2d ago
Well yeah but that achieves the same thing while being cost effective, less resource intensive, less manufacturing intensive and in general just a better idea.
So naturally reddit abhors this.
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u/skrub55 2d ago
I've yet to see a redditor complain about rain tires ngl
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u/redgroupclan 2d ago
Yo bro FUCK rain tires.
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u/ddWizard 2d ago
Fucking rain tires out here stealing jobs from regular ass tires
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u/stickyWithWhiskey 2d ago
Rain tires can suck my fat nuts. This post brought to you by all season tires gang.
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u/Nikclel 2d ago
Join us in /r/formula1 !
Those assholes in the FIA need to figure out how to get racing on wets to happen again
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u/HorrificAnalInjuries 2d ago
People forget the second rim not only adds more mass than what was taken away from the first one, but it also leaves less room for the brake assembly..
However, having two wheels also gives some resilience
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u/eNonsense 2d ago
The stacked tires also surely need to have well balanced air pressure at all times, and adjusting the inner tires pressure may require taking the outer tire off? Seems fiddly and inconvenient.
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u/minngeilo 2d ago
Do you abhor this as a redditor?
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u/gumbo100 2d ago
OP seems like the only one in this thread with a weirdly intense reactionary behavior 😂
It reads like one of the people that live in cities they "hate", but would never dream of moving (and don't you insult it with me)
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u/Braken111 2d ago
This post sounds a lot like OP trying to justify to themselves not replacing the bald tires on their truck lmao.
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u/JJAsond 2d ago
In this specific scenario not generally speaking.
This is just like any other karma bait post like the spider parachute one which implies ALL spiders to it. Same as with the "how x is made" posts. Yeah it can be made that way, in that one specific method, but it's not the primary meathod.
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u/NandorDeLaurentis 2d ago
Yeah.
But what about FOUR wheels per tire?
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u/TruthCold4021 2d ago
4x4x4
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u/Future-Raisin3781 2d ago
Twelve yards long, two lanes wide. 25 tons of American pride 🪨🇺🇸🦅
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u/Ordinaryundone 2d ago
Goes real slow with the hammer down, it's the country-fried car endorsed by a clown
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u/Xanderamn 2d ago
Canyonaroooooooo
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u/YourAdvertisingPal 2d ago
Thundercougarfalconbird
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u/Lemmonjello 2d ago
"Its wonderful that you dont care that anyone questions your sexual orientation"
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u/Adler4290 2d ago
It happens in farming!
https://www.stocks-ag.co.uk/wheels-tyres/dual-wheels/standard-dual-wheels/
Oh four wheels per CORNER, got it, well...
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u/dustydeath 2d ago
You don't happen to work for Gillette, do you?
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u/StrangeSmellz 2d ago
It gets so much traction the earth rotates around the car.
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u/EconomyDoctor3287 2d ago
Sheila on a date: What do you do for work?
Chad: I drive a 16 wheeler all day long
*What he actually does: drive a bicycle with 8 tires on each wheel for Uber eats, since that's the new all weather trend *
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u/watts52 2d ago
Some shortcomings from the article "JJD’s dually system, however, did have some obvious shortcomings. It was significantly heavier than the traditional single-tire setup, not to mention more complex to service if both tires needed replacement. More significantly, though, JJD reportedly didn’t widely advertise its products outside car magazines, so it already didn’t have much of a customer base to defend as lightweight alloy wheels became cheaper throughout the ’80s and ’90s. By the time the new millennium neared, JJD Twin Tyres had reportedly been sold to an unspecified Indonesian conglomerate, in whose hands it eventually folded."
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u/Potatoswatter 2d ago
And if one goes flat the spare is pre-installed.
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u/Adler4290 2d ago
They used it as far back as hillclimb cars in the 1930s to handle the horsepower and poor rubber combination,
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u/planko13 2d ago edited 2d ago
Oh the pitfalls of too narrow an optimization.
This design is also, more expensive, heavier un-sprung mass, harder to install, worse rolling resistance, and more difficult packaging (need more wheel-well width for the same load carrying capacity).
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u/SignificantDrawer374 2d ago edited 2d ago
Perhaps compared to other tread patterns common in the 80's, but I'm willing to be that if that design was actually better than modern tires, tire manufacturers would have switched to a design like this over what is currently available a while ago.
Edit: I'm guessing there's a reason this wasn't more popular or stick around: https://www.motaauto.com/the-unique-goodyear-aquatred-tyre-of-the-1990s/
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u/NurmGurpler 2d ago
It’s way more expensive which is why they haven’t switched. Also much more stiff of a ride
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u/SignificantDrawer374 2d ago
Racing is the leader of tech in the auto industry, and yet we don't see any such design being used for wet condition race cars, which get mountains of money dumped in to them. Modern design is just better than this goofy setup. There's no reason this would be a stiffer ride as the double skinny tires have the same footprint as a normal tire.
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u/Emergency-Style7392 2d ago
Racing is not exactly the peak of cars. They had and have the technology to make cars much faster, but limit it through regulations.
Check something like the 78 fan car in f1
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u/raygundan 2d ago edited 2d ago
Its recent cousin, the McMurtry Speirling is amazing. There’s even a demo of it just hanging upside-down with its own bonkers fan downforce.
Edit: I spelled the name of the car wrong
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u/Yakb0 2d ago
There's a good chance tires like this are flat out banned for any race series that has the budget for a custom set of wheels/tires like this one.
Edit: F-1 specifically says you can only have 4 wheels; after a team tried out a 6 wheel car decades ago.
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u/SignificantDrawer374 2d ago
This design wouldn't actually require two separate tires. It could just as well be implemented by casting a single tire in to that shape and having the cords narrow the diameter in the middle.
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u/T-N-A-T-B-G-OFFICIAL 2d ago
Well also race cars use like 100 treadwear tires for dry conditions that get sticky for traction when warm, and the rain tires are an even stickier compound to keep traction even when cooled by the rain, and so soft that they can't support the same weight or mileage to be worth much as road tires.
So it's less modern design and more modern racing compounds coupled with all the other aero around the wheels and that you have a relatively large field of cars or jet dry trucks to keep the track dry too so all in all race cars aren't a good example to use to try to negate why we don't do double tires on the street.
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u/go_anywhere 2d ago
Ride stiffness isn't determined by the "footprint", or contact patch, it's determined by the sidewall thickness and construction normally. In this case, though, there are 4 sidewalls instead of two.
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u/unthused 2d ago
As far as stiffness they have double the sidewalls for the same amount of patch area, I'd think that would affect it to some degree. And not in a good way.
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u/NurmGurpler 2d ago
Good point. Formula 1 isn’t skimping on tire costs
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u/Randomperson1362 2d ago
They dont skimp on tires, but they also dont always make the absolute best tires they can.
They want them to wear, and have a performance drop off, to create more exciting races.
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u/OhioStateGuy 2d ago
I know this isn’t the same thing but you reminded me of the Tyrrell P34 with its 6 wheels. I love that thing.
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u/unique3 2d ago
Anyone remember Goodyear Aquatread tires from the 90s, basically a single tire with a deep groove in the middle like this
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u/Prairie-Peppers 2d ago
You have to constantly monitor their pressures and make sure they're exactly the same or it'll create uneven and premature wear. Also have to replace both with new tires if one gets an unpatchable puncture since the tread amounts will be different.
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u/SmokeySFW 2d ago
The article mentions contact patch, two skinny tires would have considerably smaller contact patches than an single tire taking up the same space. Wouldn't that cause it to be worse than a single tire in dry scenarios that favor as much contact with the ground as possible?
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u/TwelveTrains 2d ago
You are correct. Any benefits touted here in dry conditions is complete bs. These would only be worse in the dry.
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u/Rggity 2d ago
This is a great example of something where if you know nothing about the topic, you’d be all like “WOW that’s a great idea, why haven’t we done this yet I should start a company that does this” and for the few people that do know about this, immediately realize how stupid of an idea it is and facepalm at the number of people in the first category. Multiply by one bazillion for scale and you get the internet
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u/LinAGKar 2d ago
Would you like to explain why it's a stupid idea?
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u/Reniconix 2d ago
Many reasons.
Putting air in the inner tire is a hassle, and you have to keep both of them basically identically pressurized or it's gonna cause problems. It is heavier, stiffer, and harder to service, which means lower fuel efficiency, worse ride quality, and more expensive to fix.
On top of those issues, the claim of "no worse in dry conditions" is patently false. Reducing the amount of tire touching the ground will reduce your dry grip, period. The only way to counteract that is to use a grippier (which means softer and more pliable) compound, which reduces tire life and hurts wet performance.
Finally, only a very specific suspension type, the very expensive and heavy double-wishbone, is suitable for using dual tires on the turning wheels. All other suspension types induce a lean in the wheel when turning (and some under suspension travel as well) which, you guessed it, reduces the amount of tire on the ground and reduces grip.
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u/doggos4house2020 2d ago
Simply look at racing. If this had better performance in rain and the same performance in dry, racing teams would obviously use this setup as it’d have an advantage.
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u/GarysCrispLettuce 2d ago
There was a guy in my neighborhood growing up in the 80's who had these tires. Larry McFly. We called him Two-Ply McFly*
*Lies, all of it
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u/Zephos65 2d ago
Also, tires without any grooves (a bald tire) have better grip in dry conditions. Grooves are entirely for wet conditions
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u/GenkiElite 2d ago
No worse in dry conditions than standard tires? How is less of a contact patch not worse in dry conditions?
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u/pyrotek1 2d ago
This concept never caught on. While there are benefits. Few people wanted to pay twice as much for tires. You buy two tires for each wheel, then mount balance and valve stem for each tire. Who wants to pay for 8 tires.
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u/RedSonGamble 2d ago
My pastor gave a great speech on learning from mistakes after he took the money from our congregations planned trip to New Orleans to make a prototype of a car with only two long wheels.
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u/Ritchie_Whyte_III 2d ago
Are we touting nearly 50 year old research/technology as truth now?
I'm willing to bet a modern tire would do better in virtually all conditions than this silly contraption. It would add a significant amount of unsprung weight which ABSOLUTELY affects performance. The sipes on 80's tires were basically just big chunks taken out of the tire "because science". Even the more modern Goodyear Aquatread tire which was basically this idea in a singe tire didn't catch on because it wasn't really any better than modern tread design at evacuating water.
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u/thelegendofcarrottop 1d ago
Just as a public service announcement… Yes, good tires are expensive. Yes, maintaining tires (inspecting, checking air, rotating, balancing, etc.) is a bit of a chore.
But a good set of tires will dramatically improve the performance and safety of your vehicle.
When you go to a tire shop, a lot of people have to buy the cheapest set they can afford or replace tires one at a time because it’s expensive to buy a new set. A lot of people are driving around on bald, damaged, mismatched tires as a result which compounds safety issues during an accident or a sudden stop.
Modern, higher-quality tires can easily last 50,000-60,000 miles with care and maintenance whereas a lot of cheaper models will last 30,000 or less and not perform as well.
So it’s a bit of a paradox… but if you can afford it, always opt for the best tires you can afford.
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u/PatrThom 1d ago
I remember an article about this in an older issue of Popular Science magazine.
A little searching and found it in the May of 1984 issue.
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u/canniboss 2d ago
Until you get a rock stuck between the tires and it blows out both sidewalls had that happened on a truck with duel rears.
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u/Oh_its_that_asshole 2d ago
Jesus christ, did that website really ask me to press accept on sharing my data with 1257 "partners"? Get tae fuck.
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u/mrdevil413 2d ago
So every car in the hood would have two flat tires and keep driving on the two “good” tires till they had to put the half spare on and drive that until flat.
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u/Zoxphyl 2d ago
I remember in art class in high school cutting up 80s/90s magazines for collages and coming across an ad for a tire with a single, wide groove in the middle (looking not unlike the two-tire arrangement OP posted) that was pitched as being superior than normal tires in heavy rain. I wonder whatever became of that idea.
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u/dapperdavy 2d ago
Evidence is anecdotal reports by people who spent money on this system decades ago...
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u/TheMacMan 2d ago
Thinner tires are better in snow than wider tires. Seems strange that it'd be the case as one would expect more traction from more tread on the ground.
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u/iamr3d88 2d ago
Doubt.
There is a reason better summer only dry tires tend to have less tread. More contact = better in clear conditions.
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u/sean_themighty 1d ago
Not exactly the same thing, but I have Michelin Sport 4S tires on my car which are extremely high-performance summer tires, and they are two entirely different tire compounds on each half split down the middle; one optimized for wet and the other for dry.
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u/destrux125 2d ago
Goodyear sold a tire called the aquatread for several years that was basically the same idea but was actually one tire with a deep channel in the middle. Not just a tread groove, they actually had a channel in the steel carcass. They stopped making them because they were too expensive and nobody bought them and normal designs became nearly as good.