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SGHOM
11-05-2007, 02:17 PM
what would happen if you put them on the wrong way round ?? :thinking:

pitslayer
11-05-2007, 02:21 PM
they wouldnt work and handle like a capri



edit:actually they would work, you would have to drive everywhere in reverse thow

MPBVr4
11-05-2007, 02:30 PM
I think dry track:thumbsup: Wet track:thumbsdow :shocked: :uhoh2:

TAR
11-05-2007, 02:32 PM
Directional tyres...ummm....don't like them as you cant swap them around easy.

I'm sure it would be like driving the most slippery of slippery things from planet slippy in the wet!

probably not recommended.

SGHOM
11-05-2007, 02:35 PM
useful info here.

http://www.etyres.co.uk/glossary-tyre-terms?term=directional

& more general info here.

http://www.etyres.co.uk/tyre-tests

WildCards
11-05-2007, 03:52 PM
I heard they'd pull your car in two, as both side of the car would want to drive away in different directions, you could of course adjust the tracking to compensate.

Wodjno
11-05-2007, 03:57 PM
what would happen if you put them on the wrong way round ?? :thinking:

What size are your tyres Derek ??

richy rich
11-05-2007, 04:03 PM
what would happen if you put them on the wrong way round ?? :thinking:
Dont tell me you didnt change them back D/pan /pan /pan

White Lightning
11-05-2007, 04:07 PM
Trying to get some extra life out of them for Combe I expect ...

richy rich
11-05-2007, 04:08 PM
Trying to get some extra life out of them for Combe I expect ...
If this is the case just get down to you local tyre shop and get them changed round.

SGHOM
11-05-2007, 04:13 PM
I'm swapping them on sunday. right to left, left to right.
I just wondered if the directional tread pattern was for water dispersment only ?? If that was the case, then I suppose they would still be ok for track use ?? :thinking: [ providing the track was dry ]

It's quicker, easier & cheaper to swap the wheels rather than the tyres.

richy rich
11-05-2007, 04:14 PM
I'm swapping them on sunday. right to left, left to right.
I just wondered if the directional tread pattern was for water dispersment only ?? If that was the case, then I suppose they would still be ok for track use ?? :thinking: [ providing the track was dry ]

It's quicker, easier & cheaper to swap the wheels rather than the tyres.
you lardarse

SGHOM
11-05-2007, 04:17 PM
you lardarse

I concur. :scholar:
But I still have not got a difinitive answer ?? :thinking:

bernmc
11-05-2007, 04:17 PM
I don't think you're even supposed to swap non-directional tyres side-to-side - only front to back.

richy rich
11-05-2007, 04:20 PM
I don't think you're even supposed to swap non-directional tyres side-to-side - only front to back.
Non-directional you swap opposite corners.
Directional front to back

SGHOM
11-05-2007, 04:40 PM
without having a set to hand..... & in my twilight years [ memory's going ] /Grrr is there an inside & outside to directional tyres ??
If so, then they cant be changed. :thinking:

Wodjno
11-05-2007, 04:46 PM
without having a set to hand..... & in my twilight years [ memory's going ] /Grrr is there an inside & outside to directional tyres ??
If so, then they cant be changed. :thinking:

Not on GS-D3's

richy rich
11-05-2007, 06:06 PM
without having a set to hand..... & in my twilight years [ memory's going ] /Grrr is there an inside & outside to directional tyres ??
No.....

zentac
11-05-2007, 06:39 PM
without having a set to hand..... & in my twilight years [ memory's going ] /Grrr is there an inside & outside to directional tyres ??
If so, then they cant be changed. :thinking:


errr sort of, kind of .....err maybe.... Depends if they are asymmetric as an asymmetric tyre has different tread patterns on its inner and outer sides. Some are both asymmetric and directional.

TAR
11-05-2007, 08:15 PM
OK long and boring reply coming up.....

You have probably already guessed that tyre makers design tread patterns to pump away as much water as possible. They do this with computer models and then test those models on trial tyres.

As tyres have got fatter, it has become more difficult to pump the water away from the middle of the tread area, or "footprint" or "contact patch" . Imagine what is happening. The tyre is rolling forward and meets a wall of water. It's quite easy to divert the water away from the edges of the tread pattern, but the water in the middle of the tyre as it meets the water has to be pushed laterally to the sides, and this has to happen quite fast if it is to be cleared away before the tyre has passed over the water.

if the water is not pumped away, then the dynamics of water and rubber mean that the tyre (and hence the car) get supported on a film of water and there is no grip to speak of, You end up aquaplaning.

In the past, tyres had symmetrical tread patterns, so that it did not matter which way around the tyre was fitted, but that was when tyres rarely went above 185mm width or so. Over the last 10 years or so, fashion has meant car owners want their tyres to be low and fat. This means tyre widths have crept up, and now a 265mm tyre is not uncommon on a high performance vehicle.

The only way the tyre designers can get the water away from underneath the tread on these fat tyres is to make the pattern directional, with those sweeping grooves that start from the centre of the tread and curve out to the edges of the tyres. You see them on fancy tyres. That pattern provides a path for the water to start at the middle of the tread and accelerate laterally to the sides of the tyre before the tyre rolls onward.

The sweeping is a kind of parabolic shape, which assumes a constant forward speed and a steady acceleration from the centre to the edge. So the curves are nearly parallel to the direction of motion near the middle, where the water is moving slowly, and they curve more steeply near the edges, as the water has accelerated laterally.

By the time the water has reached the edge of the tyre, it is moving quite fast, and hence these tyres kick up a lot of spray in the direction perpendicular to the direction of motion.

If you mount those tyres the wrong way around, then first, there is no path for the water to esape from the contact patch and second, the sweeping grooves are actually pumping water *into* the centre of the contact patch.

While the precise aquaplaning speed is hard to predict (it depends critically on forward speed, water depth and tread pattern), I would guess that the onset of aquaplaning might drop by 20-30 kph, from say 90 kph to 60 kph with four directionally-reversed tyres. (that would be in quite deep standing water with new, unworn tyres). The same applies in shallow standing water (say 2mm) with worn tyres.

SGHOM
11-05-2007, 08:20 PM
well it seems Falken 452's are symmetrical & not asymmetrical ? :thinking: therefore in theory, on a dry road/track, they could be reversed ?

Nick Mann
11-05-2007, 08:28 PM
Maybe it'd be okay, D, but as soon as it starts raining you are screwed! I would just pay minimal cash and get them swapped properly. The garage up the road from me would charge £24.

SGHOM
11-05-2007, 08:32 PM
I'm getting them done for free on sunday. :afro: twas just a theoretical question......or maybe in an emergency ??? :thinking:

Nick Mann
11-05-2007, 08:40 PM
In an emergency, I'd do it! But I wouldn't do it for long!!

White Lightning
11-05-2007, 08:48 PM
But hang on, I'm confused. Isn't the problem that the left hand / nearside of the tyres are more heavily warn due to doing clockwise tracks ... how is swapping the tyres around going to help?

bradc
11-05-2007, 09:14 PM
when you crash your car Derek, we'll all be able to tell you it was a bad idea :)

Maggie
11-05-2007, 09:19 PM
when you crash your car Derek, we'll all be able to tell you it was a bad idea :)


Hey dont say that i could be in that car :speechles :speechles :shocked: :shocked: Help do i really want to do this /rally

Spirit
11-05-2007, 09:20 PM
If in doubt don't do it.......you only have one life.....don't waste it fecking around with tyres and brakes........just fags and beer /pan

Wodjno
11-05-2007, 10:07 PM
Derek ...

Are you on 18's ??

Wodjno
11-05-2007, 10:09 PM
I concur. :scholar:
But I still have not got a difinitive answer ?? :thinking:

Nor have I ??

WildCards
11-05-2007, 10:21 PM
Eh? thi is daft, almost all tyres these days are directional, the ones we'll all be using are anyway. A symmetrical tyre (Falken 452/GSD3/T1R) can be put on any corner of the vehicle as long as it's tread pattern faces the correct direction. An asymmetrical tyre is designated either a right or a left and the tread pattern will not work properly if it's fitted incorrectly. D, if you have Falken 's you can put them on any side of the car at either the front or the back as long as they face the right direction.

EDIT/ As I was getting to before my computer went tits up. Tyres as TAR has said are designed as directional for a reason, putting a directional tyre on a car facing the opposite direction to which it is intended is not a good thing. I should imagine you'd suffer a big loss in grip as well as handling characteristics, and the wet performance would be scary.

bradc
11-05-2007, 10:39 PM
Derek, thats a good point, I didn't actually pick up on what you said before, Steve is 100% right, the FK452's can be fitted to either the left or right side of the car, but they have to be facing 'forwards'

Tyres like this http://www.1010tires.com/tire.asp?tirebrand=Pirelli&tiremodel=P%2DZero+Corsa+System

can be both asymmetrical, and directional :)

psbarham
12-05-2007, 08:22 AM
mr thevee and i noticed the drift boys at jae put the rear tyres on arse about face , presumibly to reduce the grip on the rear end