Quote from Forbin :

In LFS, "ride height" changes the suspension range and spring length while maintaining spring rate (i.e. longer but fewer coils per unit length), which also changes how high the car sits (ride height). It's a very odd way of doing it.

i dont see how this makes any difference to how you set the car up unless you adjust the ride height by large amounts
as far as i can tell the bump stop doesnt move by adjusting the ride height in lfs but the droop limit does change a little which hardly matters unless you change the setting by 10s of centimeters

the only real difference between what lfs does and adjusting preload is that you cant adjust the lfs suspensions to be fully extended while standing still which is a setting that has no application in anything but a car with silly amounts of downforce ie one that doesnt exists in lfs as it is

Quote from tristancliffe :

I think it's mostly to keep the brakes on formula cars at a sensible size. The current fashion for low profile tyres on the road is daft though, as there are no benefits to it other than, in some eyes, looks.

I think higher profile tyres are more forgiving in their break away characteristics, have a lower spring rate, wear more evenly, accept more camber with less overheating and such like, without actually reducing the ultimate 'grip'.

But I'm not really sure, so I can't give you a certain answer...

Ok well I've been doing a bit of looking around and I found THIS which seems to state that actually F1 tyres aren't as high profile as they appear. Apparently "The size of a dry front Formula One tyre is 270/55 R13, whilst a rear is 325/45 R13". I was thinking they were more like 60-70% aspect ratio, just proves how your eyes can mislead.

Also, I found THIS which seems to give a plausable explanation for the diffrences. See Weltmeisters reply.

Also seen it mentioned that an F1 tyre only weighs 10kg. Could it also be that a 13" wheel with 325/45 tyre actually weighs less than say an 18" wheel with a 325/25 tyre on it?? Are 25% aspect ratios even possible??

Quote from gezmoor :

Also seen it mentioned that an F1 tyre only weighs 10kg. Could it also be that a 13" wheel with 325/45 tyre actually weighs less than say an 18" wheel with a 325/25 tyre on it?? Are 25% aspect ratios even possible??

Certainly not, the tyres are far heavier than a magnesium wheel.

I think a lot of damping is still done through the tyres and the stiffness (or lack of it) in the large sidewall is significant and the extreme deformation experienced by such a large tyre must be pretty critical (and presumably beneficial) to the design of the car. Having said that have the teams actually got any choice as to what size tyre they want to run anymore or are the tyres the way they are simply because that's what is specified in the rules?

25% aspect ratios are available, but it would be crazy to put that on anything under 345 width, even then that seems too low. Theres high performance and then theres low profile, alot of people don't know where that line is.

Formula 1 tires are 270/55 front and 325/45 rear because at those widths the profile allows for the sidewall flex they want. The tires are also constructed to give the stiffness they want. It is infact designed to do the job a specific way.

On tin tops the tires are less standardized, the choice of tires is different, and alot of the tires you see on them can be bought for your own car provided you want to pay the price.

Generaly I keep a rule for high performance road tires. The sidewall should be kept at least 3 inches high. I haven't seen one high performance or race car with sidewalls lower than that. Going lower than 3 inches means that the sidewall has to be less stiff to compensate or the tire becomes too sensitive and breaks loose to easily.

The size of the wheel that the tire is on will realy change how it looks and often times can make a lower profile look high or a higher profile look low. 305/30ZR19s look low profile, but they arn't realy that low, they actualy have 3.6 inch sidewalls.

F1 cars still have nearly 6 inch sidewalls, which is huge and would have extremely adverse effects on a car that isn't designed around them or without having relatively extremely stiff sidewalls/special construction that bares little resemblance to production cars.

F1 tires are specialy designed for the job they do. The shape of the tire allows for all of the design variables to be very open ended, they have alot of room to play with the stiffness and the shoulder construction of the tire.

They can make a tire that has a stiff shoulder but loose sidewalls so that it has less give but still has alot of flex on cornering, or they can make it the other way so it has little flex on cornering but alot of give. Any area inbetween can be achived meaning a much wider range of handeling characteristics can be created.

I'm not sure how much these variables change from one tire company to the next, or from one type of tire to the next. But I'm sure there is a reason behind it. And the only reason I can see is that it gives F1 tires much more flexibility in design than lower profile tires would have.