I was just trawling through my jpeg collection and came accross this picture from one of the Rally of Kent's I attended. I've seen a few people asking if the tyre deformation is a little extreme. Thought this might rest any doubts about it. Just to clarify, the car did not strip a tyre at any stage on the rally, cheap road tyres just have very flexible side walls I guess. illepall
ive seen this one guy doing a donut in reverse on wet sand, it pulled the tire away from the rim and flatened it, the car was going alot slower than the one in the pic, may its just weight, angle and speed
All I know is that the tires on my car do not deflect that badly. The tires on my truck woudl be I would not drive in a maner to do that to the tires on my truck.
The being that anyone worth their salt and has a few functioning braincells would put tires approate for the activity on a car. So if you were goign to race a car even a street car you woudl be stupid to not put on a lower profile, wider tires which can handle the lateral forces with minimal deformation of the sidewalls. Idealy you shoudl find that the tires heat, wear and deform all to acceptable levels when setup correctly. I the street cars in LFS I find this rather diffacult to achieve. Its either propper heating and sloppy sidewalls/handeling or good handeling cold ass tires.
The tyre seems to be slipping off the rim just a tad bit. Never had anything close to that in real life (tyre coming off the rim). If there was no damage to the tire, then illepall
Is it conceivable that he was running low pressure tyres for dirt racing? Looks like he's coming through that corner with a lot of understeer at high speed too, maybe those two factors combined with low pressure could lead to deformation like that...
remember me when my rear tire (probably slightly under pressured) has suddenly gone flat during a corner !! Quite funny to be unable to handle my vw polo
I've had a rear right tyre roll off the rim from cornering to hard... the tail then tried to overtake the front . That was in a Nissan Mica (not much bigger than a UF1000/Mini). It was a Domino's Pizza Car and I reckon I changed the tyre quicker than any professional pit crew could just so the pizza's were on time.
Not my finest hour, but I just told my boss it was a puncture and luckily for me the tyre was never inspected to prove otherwise.
I think the point is not whether the deformation is possible in real life, but rather are the tires used in LFS accurate for what tires would be used in a street tire, club racing series or track day? This is where I think the problem is. The Road Normal tires I think act as they should, rolling very easily as they have thinner sidewalls to absorb bumps and provide a smooth ride. The Road Supers are are more akin to a performance driving tire like a Potenza or Advan, these tires are made from a softer compount and will run warmer but will also be lower profile and have a thicker sidewall. These types of tires are designed to have high grip levels, but ride comfort is a secondary thought.
When I went to the local autocross school they told everyone to increese the pressure in their tires so as to not roll the tires over on the sidewalls. Their recomendation was 45psi front and 40psi rear in a FWD and 40psi all the way around for RWD and AWD cars. Lighter cars with lower profile tires did not need to run this high to achieve the desidered results. My miata has 195/50R15 tires with a speed rating of 150mph which should be equilivent to a road super. I ran 35psi front and 30psi rear and under max lateral grip and in drift the rear tires never rolled over on to the sidewalls. They showed wear right to the edge of the tread and no further.
Now when I setup the XR GT the same way as my miata which is very close but just a little heaver and with a little more power, the tires have way too much sidewall flex. The result is that you need to run much more negitive camber to cominsate or run tire pressure way too high for optimal heating. This causes the handeling of the car to suffer and is just wrong.
In LFS all the cars are being used on a track of some sort. As such they should be using tires approate for the activity. I have a few ideas but they go deeper then just the issue of sidewall flex. I will be starting a dissusion on that elsewwere but here are the bits that are relevent here.
Wheel size and tire size need to be made more standardized, not by car but by class and application. For any given car/class the wheel diamiter should be fixed. The width should be based on the tire being used. So with a system like this lets look at the TBO class as an example. In the TBO class all the cars would run with 15" wheels. Now depending on the tires used the width and sidewall hight would change. So the knobby dirt tires might be 185/65R tires, the hypbrid might be 195/60R, the Road Normal might be 205/55R and the Road Super a 215/50R tire. This way each tire remains the same diamiter but is now designed more for the application used. You get the idea, but this can be taken even further.
Each type of tire really has two parts, the tread and sidewall. Each is tailered to the tires application. So the knobby tire, being intended for use off-road, will have long lasting tread and a semi stiff side wall to help resist roll over but still absorb impact. The hybrid a softer tread for dual purpose use and a semi stiff sidewall to absorb impact and resist rollover. The road normal is an evey day tire, designed for long life and ride comfort, as such is will have a tread that is medium to medium hard and a soft sidewall to absorb impact but be less resistant to rollover. The road super is a performance tire designed to provide the best gip a street tire can and everything else is secondary, it will has a soft tread and semi-stiff side wall.
Wow, sweet vids & pics on this thread. Agreed SamH, very comparable indeed. @Gimpster - Good suggestions, but I don't see how LFS deformation is off after seeing the slow motion vid of that Porsche above, and those are serious racing tires
That's pretty realistic. Street tires don't do heat very well. A LITTLE warmth in the tires will help, but the temps that racing tires need for best adhesion usually turn street tires into Krispy Kremes. (greasy doughnuts!) Street tires are at their best when "cold"--they're designed for normal, every-day driving--which NEVER heats up the tires to race temps.
While tyre deformation in LFS is certainly a great thing to see, I don't agree that, based on the BF1 pic, its 'realistic'. It seems sidewalls can move inward/outward a bit extreme if you look at the front left on that pic. It doesn't seem to be like real life where its almost as if the sidewalls run on the tarmac and the actual contact patch is bigger.
Its hard to say but it seems in LFS tyres deform 'linear' from top to tarmac and IRL deformation gets more severe and complex near the tarmac.
I think Gimpster has some good points with the tires. It's not so much that the tyres themselves are not behaving properly it's the type of tyre that was trying to be simulated. There isn't much of a difference in the road normals to the road supers besides grip levels, which just doesn't feel right. Yes road supers have higher grip levels but they "should" also have stiffer sidewalls coupled with a smaller sidewall ratios making the tire less prone to sidewall flex, which to me doesn't feel like the case in LFS in the TBO class. Then like Gimpster was saying because the sidwalls flex too much you have to put in more negative camber throwing off tire temps and presenting a situation that just doesn't happen IRL.
Another thing I think Gimpster was trying to say is that because of all this you have to run exteremly low temperatures to keep the tires operating at optimum temps. yes street tires have a lower operating temp but depending on the tire operating temps could be close to race tire temps.
I know the tires on my car love it when they are nice and toasty warm, warm to the point you think you might be able to warm something up on them. I would consider them close to the equivelent to Road Supers the only difference is mine are dual compound Wet/Dry performance tires (BFgoodrich KDW2 TA's 22550R16's W rated)
Actually, the Road Supers deform a bit too much for their intended pupose (Extreme performance STreet Legal tires), though this is a car dependant phenomena in LFS. Some of them are practically jut barely legal semi-slicks. Tires like BFG KD, Yokohama Neova Advan and so on are just examples.
IRL, these tires all have very stiff sidewalls. However, the degree of sidewall flexing is very car dependant, as I've noticed. The best example happens to be on the TBO class. Both FXO and XR GTT can safely run 36+psi while maintaining quick warmup (2+laps for optimal temp) without chronic overheating or sidewall scrapping after repeated lapping. However, the relatively undertired RB4 can't avoid rolling on the sidewall without 40+psi pressures OR running massive (3+degrees!) negative camber. If you check F9 you'll definitely notice that the RB4 practically places no detectable load on the inside edge of the outside tires when running pressures such as 36psi. Unless of course you run -3.5degrees camber, which will kill the inside tread.
The sidewalls of all the slicks seem to behave perfectly realistically (no excess flexing). As for the road super equiped cars, they are fine overall, though it's definitely much more noticable in the relatively narrow or undertired cars. IRL, a compact sedan with OEM all-seasons would practically scrape it's rims on the track if run at the absurdly low OEM (32psi or less) pressures at race speeds seen in LFS.
Point is, LFS sidewall flex isn't too far off RL. Just that the Road Supers could all use slightly stiffer sidewalls.
illepall
!! Quite funny to be unable to handle my vw polo 
