Directional tyres and the wet.

[Tony Crossley]

Hello, I wonder if anyone can confirm something a tyre fitter at Oulton park was telling me about directional tyres. (IE: Yoko A032R's)

He was telling me that the reason the tyres have an 'outside' and an 'inside' is not to do with the tread pattern so much as the construction of the inner and outer tyre walls. The outer wall being stiffer than the inner. All to aid turn-in, girip, etc.

What interested me was that he recommends that you move the directional tyres to the other side of the car in the wet. IE, the directional arrow on the tyre is pointing backwards. This is becuase you then have a softer, more compliant outer sidewall and this helps grip in the wet.

Now, was he having me on?

Tony

[bloggs]

Not sure about the Yoko tyre, but the reason for the arrow and the directional tread pattern is simply to get the water on the track out from under the tyre, if you run them backwards it would funnel the water back into the centre of the tread, thus no traction, you spin, and you loose....

[Tony Crossley]

That's what I always thought but then I'm not the brightest bulb in the lampshade....which is why I'm seeking few other opinions

[Raglanparade]

Um... that would be the case if you put the treads on backwards.

What if..

You just switched the sides the tyre was on. So you put the LF tyre on the RF side, and vice versa.

then you would have the tread patterns in the right direction, with the softer tyre walls.

[SeaneyC]

Yes, i think you just worked it out wrong in your head Tony, if you put the left hand tyre onto the right hand rim, and the direction was reversed, then the outer wall would still be on the outside of the tyre, not to mention the tread issues outlined already! Basically the tyre guy meant mounting a right hand side tyre onto the left hand side rim and vice versa, not mounting the entire right hand side wheel onto the left hand side axle! (which would reverse tread direction)

[Tim Falce]

I cant see how the tyre wall can be stiffer one side or the other or have an outside or inside, only a tread direction and mybe the way the steel is layed up inside. If you mount a tyre on the near side, the right tyre wall will be on the inside, if you mount the same tyre on the off side, the same wall will be on the outside. Of course this will mean turning the tyre on the rim to get the direction correct.

[bloggs]

Dont you guys think that the tyre maufactures, haveing spent lots of dollars/yen/pounds, on finding which way a tyre rotates the best for wet weather handeling, just to be out witted by a tyre fitter, seem a bit wrong?
They dont make tyres with directional tread paterns just so they can be fitted backwards.
Thats why they are called DIRECTIONAL TREAD PATERN TYRES..........

[Anuauto]

The experience of most is surely that so-called "road" tyres like the A032 and A048 are little better than slicks anyway the moment there is actually any water on the track. The only relevance would therefore be to a category that mandates their use at all times. Directional arrows should not necessarily point the same way - Michelin "rally" racers were recommended by the manufacturer to be fitted differently for RWD and FWD cars (because of tyre construction, not tread). Knowing the performance of A032s etc in true wet conditions raises the question of how responsible it is of certain vehicle manufacturers to fit them as OE...

[shiny side up!]

Most treaded / directional tires for wet or dry are not symmetrical in the tread area side to side because of anticipated camber geomety, as well...

(yes, my post appears to be a bit random )

[Al Weyman]

I have heard this and seen guys (one a very experienced racer as well) reverse the tyres (we were using Falkens at the time) and swore they work better in the wet, I personally subscribe to Blogg's point of view however anything made for the street will always be a compromise so you never know there may be something in there.

[MikeBz]

It depends on the tyre. Some tyres have a directional tread pattern, and some have a construction which requires the major loading to be in a particular direction.

[Andrei]

I don't know the tyres you are talking abot - have they symetrical patern or not?
If it is symetrical, I can not believe that the tyre is better when mounted vice-versa. Maybe, that is true if the tyres are more worn on the inside because of camber and revercing them, you have more tread depth.

The only tyres I know that have different properties in- und outside are oval track tyres in the US, but I think only for proffesional race series.

[Richy_Rich]

Anyone tried fitting them inside out?

[graham bahr]

it can be either the tread pattern OR the construction that makes a tyre directional, after all my slicks are directional and they didn't have a tread when i last looked,

at one meeting i got a puncture and had to fit a "spare" slick fitted the wrong way round and to be honest i couldn't tell the difference.

[AndyV]

I've run an A032R the wrong way round in the dry and it made no difference. I go with the treadpattern methodology for clearing water so will always run them in the right direction if possible. Personally I found the 32s to be fine in wet conditions and have never used a set of 'proper' wets.

I tend to always keep the same tyres on their own car corners as I think the mound themselves to the camber so if you switch them round you could end up using less tread than you would have done if left on the original corner.

Cheers
Andy

[Tony Crossley]

Thanks all, I'm sure I'm wiser now but I haven;t yet realised!

We have to run road tyres, not slicks - hence the A032Rs. I think I'll stick to the direction arrows, but should I be at a wet test session I might give it a go -just for interest sake....

[graham bahr]

motor cycle tyres are often fitted opposite ways round depending on if they are to be fitted front or rear

[maddogf3]

Originally Posted by graham bahr

it can be either the tread pattern OR the construction that makes a tyre directional, after all my slicks are directional and they didn't have a tread when i last looked,

at one meeting i got a puncture and had to fit a "spare" slick fitted the wrong way round and to be honest i couldn't tell the difference.

Ah graham! , we meet again ,
its the way the rubber is joined as well as the direction of the bands are overlapped . My mate "Howie" ran the tyre competions department for EAR's motorsport for many years and has a bit of knowledge on tyres He used to hand cut tyres for rallying ( so if you need any info just ask away ) having said that he was 60 last month so must now be getting to be an expert on Bus tyres We ran ff tyre the wrong way purely for cost reasons at Ty Croes cause it was so hard on outside tyre .it didnt effect lap times or temps . But we only raced for 15mins Howie moaned something about direction and " Its not right runnin them that way " I switched my deaf aid off
Regards Martin

[dtype38]

Originally Posted by Tony Crossley

We have to run road tyres, not slicks - hence the A032Rs. I think I'll stick to the direction arrows, but should I be at a wet test session I might give it a go -just for interest sake....

I've run 032s for a while now and swap mine around regularly to get even wear across a set (for purely financial reasons). I find in the wet that the grip is excellent up to a point, but they aquaplane at the slightest excuse. I think its simply that there isn't enough tread to clear any depth of standing water, so like slicks they work fine in the damp, but keep clear of those puddles. IMHO the tread pattern is just for show, it qualifies them as road legal, and it probably doesn't matter which way round you run them!

[johnh875]

Tony there are some tyres which are asymmetric as well as directional (some also asymmetric and non-directional too I think) such as Yoko A008. Apart from those types (obvious from tread pattern) I would say the tyres would not be suited to one side of the car or the other – if that were the case it would be marked on the sidewalls.

[dtype38]

Originally Posted by johnh875

Tony there are some tyres which are asymmetric as well as directional (some also asymmetric and non-directional too I think) such as Yoko A008. Apart from those types (obvious from tread pattern) I would say the tyres would not be suited to one side of the car or the other – if that were the case it would be marked on the sidewalls.

I think you'll find that Yoko A008s have a direction arrow, but if you buy a set from a Yoko main dealer they'll send you four left hand side tyres and tell you to ignore the arrows

[johnh875]

You wonder whether Yokohama has noticed the resulting discrepancy in the number of LH and RH tyres sold then? And whether they have followed up such an observation? I also wonder how many customers would think such a recommendation was ok?

[dtype38]

FWIW my Yoko supplier is a respected motorsport supplier and his explanation was that some time ago the Right Hand mould became worn out and Yoko decided demand wasn't high enough to justify renewing it. They continued producing left hand tyres for the hardcore of A008 fans saying that they could be used for both sides.

I had heard rumour that a new Right Hand mould may have eventually been made, but I've not seen any new right hand tyres, so can't confirm that.

[johnh875]

Ok, that just raises another question though... why would the RH mould wear out before the LH one... (ps if you know the answer I will be very surprised!)

[dtype38]

I hearby fail to surprise you

Just out of interest, there is the small posibility that during a recent 360deg spin at Coppice (Donnington Pk) I may have momentarily managed to get all of my A008s rotating in their correct directions. (If you know if I actually did or not, I'd be very, very surprised)