hi,
i know low profile tyres make your cars handling pretty crap but could someone explain why it does
i know low profile tyres make your cars handling pretty crap but could someone explain why it does
how does low profile tires afect handling
The idea is it eliminates sidewall flex so that your steering is more responsive. It should improve handling, not make it worse. It will make the ride more rough though, since you've not got as much cushioning between road and shocks.
Less movement and flex in the tyre due to shorter sidewalls mainly which give a worse ride, as the tyres play some part in absorbing shocks, and when you run alot lower profile, then all these little bumps and shocks that the tyre would usually removed will be tranferred to the suspension and the steering.
I went from 175/70/14 to 205/40/17 on my astra and although it gripped a lot better in the dry, it was horrible in the wet, bumpy as hell through the steering and used to tramline like mad all the time, so what you gain in roadholding in good dry weather is cancelled out as it gets worse than before in wet weather, plus the handling isnt very nice.
@ dajmin, i see what you mean, but road holding and handling arent the same thing, roadholding is better in the dry but worse in the wet, but the handling itself will not be as nice IMO, some would say its more responsive, but i would say that having the steering wheel jerk all over the place everytiime you drive over a stone or a small pothole isn't more responsive, just overly twitchy.
I went from 175/70/14 to 205/40/17 on my astra and although it gripped a lot better in the dry, it was horrible in the wet, bumpy as hell through the steering and used to tramline like mad all the time, so what you gain in roadholding in good dry weather is cancelled out as it gets worse than before in wet weather, plus the handling isnt very nice.
@ dajmin, i see what you mean, but road holding and handling arent the same thing, roadholding is better in the dry but worse in the wet, but the handling itself will not be as nice IMO, some would say its more responsive, but i would say that having the steering wheel jerk all over the place everytiime you drive over a stone or a small pothole isn't more responsive, just overly twitchy.
#4
- Crashgate3
Low profile tyres without changing the wheels will also alter your final drive gearing as the whole tyre/wheel will be a smaller radius.
What's 'tramlining'?
What's 'tramlining'?
When your car pulls all over the road according to the camber of the surface, to experiance what this feels like, find a motorway somewhere where the lorries have made a kind of groove in the slow lane then try and drive in that lane, your car will try and pull itself into one of the grooves, which is how a car with overly wide and big wheels will behave a lot of the time on most roads.
Tram lining is when the tires follow grooves and stuff in the road.
Edit : Beated.
Edit : Beated.
#8
- Crashgate3
Ah, I get you 
I nearly got killed by something similar a few years ago on my mountain bike, riding in the snow.
The road had about half an inch of snow which had melted slightly then frozen solid, but not before a few bikes had gone through it leaving tyre tracks. At some point there had been a parked car which had since moved which now had bike tracks going round it - I got my wheels caught in one of these tracks which dragged me out into the traffic next to me. Not fun.
I nearly got killed by something similar a few years ago on my mountain bike, riding in the snow.
The road had about half an inch of snow which had melted slightly then frozen solid, but not before a few bikes had gone through it leaving tyre tracks. At some point there had been a parked car which had since moved which now had bike tracks going round it - I got my wheels caught in one of these tracks which dragged me out into the traffic next to me. Not fun.
Low profile tyres can be made to improve handling, but only by changing the spring rates, damping rates and (probably) the suspension geometry. If you don't change anything - i.e. just bolt on lower profile wheels/tyres - then you are massively likely to not only look like a chav, but also to ruin what handling/balance/grip the car might have had.
tristain said what i forgot to say lol, if you have other work done on suspension and stuff then you will get a better ride and handling, although this isnt always cheap, or really worth it for everyday driving to work and back kind of use.
I really doubt that. Unless the suspension bits are not just some random aftermarket suspension that was "tested for your car" by the company producing/selling them.
Car companies spend millions on testing cars. Tuners spend nothing compared to that. You're better off with a stock car, unless you spend serious money on the upgraded parts (more than a few hundred quids).
Yes, but car companies mass produce their vehicles to be cost affective, have nice comfy handling and good component life, not to squeeze the last drop of road holding ability or grip available out of the car, as bog standard is good enough for your average joe driving around town, but for those who want more grip and more precise handling, it comes at a cost and you compromise ride comfort.
No, but if the car companies WERE trying to squeeze performance out of them, they don't buy suspension from a catalogue and hope that the manufacturers know what they're talking about - most don't. They (the manufacturers of aftermarket parts) are generally trying to pursuade idiots to buy their stuff, so they are made to a price, sold at a premium, and with next to no 'testing'.
The only way they get away with it is because most 'modders' wouldn't know bad handling even if it slapped them in the face.
The only way they get away with it is because most 'modders' wouldn't know bad handling even if it slapped them in the face.
This.
i was just trying to explain to my dad thats why i created this thread and its not about road handling was trying to explain how low profile tires would be terrible racing round a track i just dont know why and dont know how to explain
You can't simply throw a blanket answer over a question - you can't simply say lower profile tyres will make your car worse because there are so many other factors.
Differences in the quality of tyre and even simple tyre pressure can have as much of an effect on handling as changing the profile. A budget low profile tyre might flex more than another brand with a higher profile, for example.
As for low profile tyres on track, look at Touring Cars and WRC cars
Differences in the quality of tyre and even simple tyre pressure can have as much of an effect on handling as changing the profile. A budget low profile tyre might flex more than another brand with a higher profile, for example.
As for low profile tyres on track, look at Touring Cars and WRC cars
If you have lots of money, then you probably can fit lower profile tyres and maintain or improve the handling for track use, where it's relatively smooth. Few tracks have potholes (unless you believe Intrepid, who thinks all tracks are unpaved in the UK because Donington won't be hosting an F1 race next year. But he's an 'exception').
But don't confuse handling with grip. It's very easy to improve one or the other. The skill (and money, and time) is in improving both at the same time. Professional racing teams with 7 or 8 figure budgets often fail at this. So why should a spotty 17 year old with a credit card (probably his mothers) be able to improve both from a magazine?
What Dubster says is also true. Specific examples from said catalogue might, by chance, be brilliant. The difference between my Avon racing slicks and the Silverstone racing slicks is massive. Yet they are the same size. Roughly the same compound. On the same wheels. But the Silverstones are quite a bit more rigid around the shoulder. Small difference, MASSIVE change.
But don't confuse handling with grip. It's very easy to improve one or the other. The skill (and money, and time) is in improving both at the same time. Professional racing teams with 7 or 8 figure budgets often fail at this. So why should a spotty 17 year old with a credit card (probably his mothers) be able to improve both from a magazine?
What Dubster says is also true. Specific examples from said catalogue might, by chance, be brilliant. The difference between my Avon racing slicks and the Silverstone racing slicks is massive. Yet they are the same size. Roughly the same compound. On the same wheels. But the Silverstones are quite a bit more rigid around the shoulder. Small difference, MASSIVE change.
Out of curiosity, different in what sense? Better or worse? Or really just different?
From my understanding the sweet spot with low profile tyres is ~50%, anything less and it is just an aesthetic feature that compromises handling. Of course, most people want low profile tyres because they "look mint" and not because they need the car to drive any better. Which is why the SLK AMG BS has a slither of rubber wrapped around the wheels. It drives like shit but looks "sporty" and then snapped up by footballers.
So their shopping list is usually pulled from an article Max Power and the free stickers with said magazine get slapped on the doors of their car to show they world what they want to put on their car.
So their shopping list is usually pulled from an article Max Power and the free stickers with said magazine get slapped on the doors of their car to show they world what they want to put on their car.
Was that directed at me, about the Avon/Silverstone differences?
If so, I think it's the steel radial belts that have a different layout, giving a lot more stiffness around the shoulder. As such the tyres need to be used in a very different way. On our car, even with the suggested (by the manufacturer) setup changes, the car was skittish, unpredictable, and took about 10 laps before they came on song. And once they did, they were still skittish and unpredictable. It gave me no confidence.
Another team, this time in BRSCC F3 (effectively the next rung up the motorsport ladder from me, but still amateur, just with more money) tested the same tyres, and the driver (who wants to get into British F3 next year I think, so can't be that bad) couldn't get within his Avon pace on Silverstones. As his Avon pace was pretty stunning, I'm led to believe it wasn't lack of talent...
If it wasn't directed at me, ignore the above.
Yes yes, it was directed at you
So the cheaper tyres come at a price after all.
So the cheaper tyres come at a price after all.
Indeedily. No cheap tyres for me next year Now, where did I put that sponsorship form...
Now, where did I put that sponsorship form...i still think youre way way overstating the effect of changing the wheels and the amount of thought that goes into suspensions on anything that isnt a ferrari or similar
most cars these days offer a range of wheels often with different diameters and thus different profile (also probably with different wheel weights) and i rather doubt that they bolt on different dampers and springs depending on the wheels you choose
obviously what you dont want to mess around with is the centerline of your tyres particularly on the front so as to not mess up the scrub radius and all the parameters that go into steering feel
aynthing else however i reckon will hardly make a difference
as for the actual topic the most important thing doesnt seem to have been mentioned yet which is cornering stiffness
its essentially the stiffness of a tyre against lateral (sideways) loads which obviously if you replace most of the sidewall with metal will increase
as for the handling what happens is the peak of the sideways force the tyre produces moves to lower slip angles which in handling terms means the tyre will change between having a feel of gripping the road to feeling like youve lost traction (even though you dont but thats a different discussion) much more quickly and violently than a tyre with high sidewalls
195 / 50 / R15, peak slipangle ~ 11 degrees, stiffness 1400N/deg @ 6000N load
325 / 30 / ZR19, peak slipangle ~ 6 degrees, stiffness 3000N/deg @ 6000N load.
Glass is right!
325 / 30 / ZR19, peak slipangle ~ 6 degrees, stiffness 3000N/deg @ 6000N load.
Glass is right!
Like shotglass said, a tyre with a higher sidewall will allow you to feel the limit well before you reach it as the feeling leading upto a loss of grip is more gradual, but with lower profile tyres that gradual feeling is gone, so you have grip, and then no grip, or should i say a feeling of no grip , a bit like LFS tyres! 
Also, it isnt really that easy to answer the question of what negative effects will lower profile tyres have on handling on its own, as most of the time when people upgrade wheels or whatever, the tyre doesnt only become lower profile, but is actually a wider tyre to start with, so comparing lets say a 185/60/14 to something like a 205/40/17 is difficult, is it the extra width and therefore wider contact patch of the tyre that makes it handle worse, or the very short sidewalls of the tyre, or the width of the rim, or the diameter of the rim, or the offset of the wheel, is the wheel heavier than the standard ones were, so unsprung weight comes into it, is the rolling radius bigger or smaller than the originals, etc., as all of these things combined will play some part in making the handling completely different, its just knowing which specific attributes make it overly worse or better, which isnt easy to determine.
Also, it isnt really that easy to answer the question of what negative effects will lower profile tyres have on handling on its own, as most of the time when people upgrade wheels or whatever, the tyre doesnt only become lower profile, but is actually a wider tyre to start with, so comparing lets say a 185/60/14 to something like a 205/40/17 is difficult, is it the extra width and therefore wider contact patch of the tyre that makes it handle worse, or the very short sidewalls of the tyre, or the width of the rim, or the diameter of the rim, or the offset of the wheel, is the wheel heavier than the standard ones were, so unsprung weight comes into it, is the rolling radius bigger or smaller than the originals, etc., as all of these things combined will play some part in making the handling completely different, its just knowing which specific attributes make it overly worse or better, which isnt easy to determine.
how does low profile tires afect handling
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