r/F1Technical • u/AleBK89 • Apr 17 '21
Picture/Video High amplitude oscillations of the rear right tyre at Variante Alta
168
u/gdj4ever Apr 17 '21
this looked very creepy, is this normal or it is faulty and could get punctured?
143
u/EliminateThePenny Apr 17 '21
While it's not a good thing, it's pretty much harmless.
48
u/FuckTrumpBanTheHateR Apr 17 '21
I feel like this is going to speed up tire wear and increase temperatures.
35
3
u/pinotandsugar Apr 28 '21
Far from a tire expert but it is hard to believe that it does not put the tire at greater risk of failure and heat buildup in areas not designed for the amount of movement.
141
u/Hollandse_Herder Apr 17 '21
It's normal. All tyres do it but it happens too fast for the human eye.
35
u/JKraems Apr 17 '21
There's videos floating around the internet of dirt sprint cars and even sometimes NASCAR tires that will slowly pull like that through the corner and then go back on the straights. It's just how physics works
31
u/TheRiseAndFall Apr 17 '21
You don't even need to have that much force, speed or even grip. I put a gopro cam on my front fender of my Miata to see how close I was getting to the cones in my autocross runs. The amount of visible tire flex on a street tire at 20-40mph was crazy.
28
u/CouchMountain Adrian Newey Apr 17 '21
It's common in almost all motorsports.
A good example of something somewhat similar is on drag racers. They expand as they get faster but they still hold the bead, but in F1 they're mostly moving side to side instead of up and down.
18
10
u/KILLER5196 Apr 18 '21
Top fuel dragsters are some of the most insane cars
6
u/CouchMountain Adrian Newey Apr 18 '21
Absolutely! If you ever get the chance, definitely go watch. The punch you get in the chest when they launch is crazy.
Plus the pits are open so you can watch them rebuild engines between runs. Super cool.
8
u/MattytheWireGuy Red Bull Apr 18 '21
Top fuel makes more downforce on the rear wing than multiple F1 cars. The roar is something else though, I explain it as a huge bomb that keeps exploding cause thats how it feels in your chest and it literally shakes your eyes when they pass you. The pits are the best for newbies cause you make them stand there while you get tear gassed when they fire the motors up and its awesome to see the whole crowd jump back when they whack the engine https://youtu.be/NaEvWfonLiY
-3
u/robertocarlos68 Steve Nichols Apr 18 '21 edited Apr 18 '21
cause they go faster - they basically have no diffuser, just huge wing
10
u/MattytheWireGuy Red Bull Apr 18 '21
True, but that wing is not much larger than an F1 wing but it makes close to 6.5 tons of downforce doing it. Hell they make a half ton of down force purely from the exhaust. Everything on a Top Fuel rail is just mind blowing from fuel flow to air flow to horsepower and g force, everything is kicked up a few notches. I dont know how efficient the motors are, but ~13000 hp from 8,2 liters is pretty damn impressive.
-1
u/robertocarlos68 Steve Nichols Apr 18 '21
sure impressive, but for me it's lacking that "poetry" (fine engineering), efficiency and it just runs ~4-5 sec in straight line and that's that.
10
u/jabbasslimycock Apr 18 '21
Idk man, I think engineering a car and engine that can handle burning 60liters of fuel in 3 seconds is pretty damm fine engineering. Even a chassis that long that can handle 6.5 tons of down force and tires that allow accelerations of 8 G which is twice the maximum acceleration of the space shuttle is pretty fine engineering to me.
2
u/CouchMountain Adrian Newey Apr 18 '21
Watch the video I linked above about it. It might change your mind.
I am not a huge fan of drag racing either but top fuel is something else and I have a ton of respect for them.
1
u/robertocarlos68 Steve Nichols Apr 19 '21
I saw a document about it, but I mean they only focus about one (or rather 2) things - go fast in straight line on perfectly flat road and then brake.
1
47
u/Pahasapa66 Apr 17 '21
In my mind's eye I still see Lauda and Andretti's tires deflecting like a dragster as they punched the accelerator going uphill into the last corner at the original Long Beach. So much weight transfer to the rear that only the areo held the front wheels down so they could take a right onto the front straight. Good thing they got rid of that section.
5
u/Pentosin Apr 18 '21
Got a link?
12
u/Pahasapa66 Apr 18 '21
Nope. Far as I know it doesn't exist. I saw it live.
8
u/Pentosin Apr 18 '21
Ah, ok. Thats cool tho.
8
u/Pahasapa66 Apr 22 '21
Hey...
Just found a vid of Patrick Depailler in 1978 Tyrrell 008 as he does a lap at Long Beach. Though you can't see the effect I wrote about, you can see that part of the track with the extreme uphill climb.
https://twitter.com/GazTankMotors/status/1379721736162320385?s=19
2
1
54
18
u/stillboard87 Patrick Head Apr 17 '21
What effect will there be in setup/performance/reliability with this being reduced next season with lower profile tires.
29
u/Odinfoto Apr 17 '21
Seeing as how the teams designed the cars around these tires and the large volume tires provide a lot of the spring affect there by the suspension of the car has less travel and stiffer suspension set up to compensate for the big voluminous tires. Next years cars will have tires with a lot less volume so the entire suspension system will have to be redesigned to compensate for less travel and a higher spring rate so more travel will have to be designed into the suspension which will make the car heavier, increased complexity and pretty much affect all other engineering decisions in the rest of the car.
5
u/MattytheWireGuy Red Bull Apr 18 '21
Suspension design and setup will be radically different than its been before. The pneumatic damping of the sidewall accounts for the lions share of suspension "travel". We are going to see setups and designs that look a lot more like LMP1 cars and a lot more focus on dampers again. Id like to see the regs allow for some sort of active suspension damping, not necessaril Williams/Newey active but more linked solenoid controlled setups but hope ABS and TCS never see the light of day on them.
1
15
u/no2jedi Apr 17 '21
God I love these oscillations. The wobble is so cool. I've got so many gifs on my computer.
5
2
9
Apr 17 '21
This is like 1960s problems still in 2021
22
5
8
3
u/DropporD Apr 17 '21
Awesome! What causes this effect?
16
u/redsox985 Apr 17 '21
It's the tire catching and losing grip. It returns to center (and overshoots a bit) when it loses grip as the ground is no longer dragging against it with any significant amount of force. Then it regains traction, but the vehicle is sliding sideways, so the grippy tire is holding it's place as the car continues to move sideways. It stretches out the sidewall again until the stored energy inside springy rubber overcomes the amount of grip the contact patch can provide and it slingshots back to center again.
2
u/robertocarlos68 Steve Nichols Apr 18 '21
It only happens in lower speed corners where downforce is small, right?
7
u/AleBK89 Apr 17 '21
I think you can see it as a mass-spring-damper system with a force applied to it. Force being the lateral one applied to the mass (the tyre) from the asphalt, the rim. The spring and the damper are the gas inside the tyre and the elasticity of the rubber itself.
1
u/Pahasapa66 Apr 17 '21
A combination.
First, the car is sliding right, so the car weight is going in that direction.
Second, the ntrogen that inflates the tire is not up to maximum heat, so the pressure inside the tire is lower than optimum.
So, all that weight is going to the right and the tire has a low pressure. The tire is moving back and forth on the wheel rim, and as the tire heats from the slide, so does the nitrogen inside. These forces togeather make the tire slip and then reseed to the wheel rim.
3
u/carstuffaccount Apr 19 '21 edited Apr 20 '21
/u/GaryGiesel - (how) do you simulate these deformations and their knock-on effects? Can/do the n-post rigs replicate the lateral forces on the wheel assembly? Thanks!
3
u/GaryGiesel Verified F1 Vehicle Dynamicist Apr 20 '21
To be honest this is a question best directed at a tyre expert - it’s one of those very detailed phenomena which certainly isn’t modelled in the relatively simple tyre models I’ve personally used, but I suspect the complicated physical models that the experts use may model this sort of dynamics. Again, not an expert on ride or rig tests, but I don’t think you can really simulate this on a 7-post rig either. Not only do all the machines I’ve ever seen only apply vertical load, but more importantly in the rig tests you tend to use different tyres, which have a construction designed to mimic the vertical stiffness of a spinning tyre while stationary. (This sort of rig tyre is something that Pirelli supplies, along with things like wind tunnel tyres and show tyres)
2
u/carstuffaccount Apr 20 '21
Thanks for chiming in, anyway! We really appreciate your participation in the sub.
1
u/ipSyk Apr 23 '21
TMeasy Version 6.0 actully does eigenmodes really well.
Version 6.0 an extension to the standard TMeasy version 5.3, takes the first two rigid body eigenmodes of the belt into consideration. These modes represent the in plane longitudinal and rotational movements of the belt relative to the rim. The dynamics of the longitudinal force is of higher order then and reproduces the tire wheel vibrations, required for indirect tire-pressure monitoring systems (iTPMS) of second generation sufficiently well.
From: http://www.tmeasy.de
2
u/crashd8890 Apr 17 '21
I think it has been mentioned, but didn’t notice it totally addressed in previous comments. When I watch this I can’t help but feel that this must really rapidly increase tyre temp and wear? I imagined the tyres blistering after a few corners like this. Any super fans, or resources, that can explain this in detail? Thanks in advance, newish fan haha
1
Apr 17 '21
[deleted]
6
u/sonor_ping Apr 17 '21
Define dangerous. These cars are going up to 200mph around a twisty circuit, turning as fast as possible. The whole thing is on the edge dangerous. But these tires are made for this, so this oscillation doesn’t add to the danger.
4
0
1
1
1
1
u/Andysan555 Apr 18 '21
I guess that if the Pirelli tyres were far more optimal than they are we would see less of this?
1
1
u/callmelampshade May 21 '21
I noticed on Lewis’ onboards his front tyres were doing this a lot yesterday.
1
1
218
u/Matsugara16 Apr 17 '21
That's tamburello but cool nonetheless