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Lotus in the Peak
28th - 30th June 2024

Running Tyres In The Wrong Direction?


Icsunonove

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Hi,

 

Could anyone tell me if they have tried running the Advan Neova LTS tyre on track in the wrong direction? The reason for asking is this....

 

Most tracks are clockwise. The left rear particularly takes a beating and the left front is not far behind. We are getting through an awful lot of left rears in particular. We end up replacing the left rear and running the right rear with whatever tread it has on it at the time. I was wondering if it would be possible to balance up the wear on a dry track.

 

I know you are only supposed to run them in one direction, but is this just the case in the wet?

 

Sorry for my ignorance, thanks for any replies, Tom

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could you not just use non direction specific tyres if all you're doing is caning them round a track? be cheaper aswell.

 

i knew someone who used to track a subaru and as he wasnt that concerned about the lap times, more about having fun, he just used cheap tyres.

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I remember that a similar question came up on the Seloc forum a while back - something to do with Caterham drivers putting their rear tyres on reversed to get better grip under braking. Have a search there and you might get some useful info

 

If I remember correctly, the tyre side wall tends to stretch rotationally with use as it's bedded in (a few hundred miles I think). If you take it off and put it on the other side it'll need to bed in and stretch in the other direction. This can cause unexpected side-wall failures.

 

How dangerous and common this problem is I don't know. All the above is a hazy recollection of some comments made by Seloc members, have a search there

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By the sounds of things I wouldnt risk having a blow out myself for the sake of a few pounds. Much more expensive in the long run if something happens on track at speed.

 

Surely cant help the handling as the tyres were made to be directional?!?

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Be cautious of running rotational tyres the wrong way around on the road. A mate ran into the back of someone in his Golf and when they insurance saw one of his tyres was on the wrong way around they decided they weren't paying out anymore!

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Thanks for replies. I am not talking about wet weather or road use. What I am really asking is if you took all the rubber off and just looked at the canvas and construction, are they still uni-directional then? I.E Is there anything in the construction that makes them uni-directional? (I would have thought not, but I am not sure)

 

Mr Belowski, that's interesting, but I still don't understand. Obviously during acceleration and braking the tyre is subjected to forces in the opposing directions, so I don't really understand.

 

Reason I am asking is that we are getting to a situation where say the left front is scrap because the outer edge is showing the canvas. However the rest of the tyre still has legal tread on it. So we are throwing away a lot of rubber. Obviously on the road the tread wear is far more uniform. So if I could do half a trackday and then swap the tyre round I will get more life out of the tyres. I hope you can understand what I mean

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Yeah, must admit that I don't exactly understand it myself. The car's mass remains constant, and the net total of all the acceleration it does has to be zero (otherwise it'd always be moving :angry:), so the total force the tyre is subject to is the same in each direction. OK, it's not that simple once you take weight transfer into account but you get the idea.

 

I guess the weight transfer causes the rears to be subject to greater forces under acceleration and lower forces under braking, and vice-versa for the fronts. This effect would be far more significant for the fronts as they're coasting or braking (they see no longitudinal accelerative forces at all). So the rear side walls would have to be strong in both directions, but not the fronts. But then, I would be suprised if a fundamentally different construction method was used for the fronts

 

The honest answer (as you can tell) is that I don't know but it's an interesting question :)

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Directional tread is to do with best grip in the wet. I.e. it will always be a compromise to removing water from under the tyre if it can be used in either direction. Much better to ensure the tyre rotates in one direction.

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Here's what I am on about. Here is the left front tyre after a very heavy day at Elvington (very abrasive):

 

210905_005.jpg

 

The outside of the tyre is almost down to the canvas. There is 5mm of tread on the inside.

 

If I went to another clockwise track I'd have to change it within an hour or so. If I could run it on the other side I may well get half a day out of it, maybe even the full trackday.

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http://www.ltsa.govt.nz/vehicle-safety/kee...tml#directional

 

http://www.pirelli.co.uk/en_GB/tyres/car_s...aq/faq_gb.jhtml

 

What are the consequences of fitting an asymmetric tyre the wrong way round?

A: An asymmetric tyre has a tread pattern divided laterally into distinct elements, each designed to confer a particular aspect of performance. Typically, these elements range from a dense outer section to promote lateral stability and fast steering response during cornering, through to a more open inner section with blocks and drainage channels providing higher levels of wet grip, and thus, a reduced risk of aquaplaning. Pirelli asymmetric tyres have "INNER" or "OUTER" moulded into the appropriate sidewall.

If fitted incorrectly, the advantages offered by the asymmetric pattern will not be realised.

Tyres not fitted in accordance with the indications on the sidewall are a reason for MOT failure.

 

etc etc.. lots on those url's

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Here's what I am on about. Here is the left front tyre after a very heavy day at Elvington (very abrasive):

 

210905_005.jpg

 

The outside of the tyre is almost down to the canvas. There is 5mm of tread on the inside.

 

If I went to another clockwise track I'd have to change it within an hour or so. If I could run it on the other side I may well get half a day out of it, maybe even the full trackday.

 

 

Looking at your picture get the geo done or look at driving style, that has nothing to do with the tyre construction.

 

Directional tyres should only be run in the correct direction, there are other factors than just water clearance. I haven't looked at the links Mark put up but guess it will explain about construction etc.

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Caterham's run the CR500 the wrong way around on the front on their race cars for improved grip under braking.

 

By there construction will allow that. (I might be wrong in my understanding in how it was explained, but I think that is because they are xply and the lightness of the car. many other tyres layering would get ripped apart under heavy braking).

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