Apart from not being able to clear standing water, what would you reckon happens if you just swap the right and left wheels (tyres included)?
I know, shouldn’t do it, but just need to know what happens.
I have tried dismounting them and passing them to the other side (to respect the rotation), and this was horrible, since the rubber has already been pulled to one side due to the cornering forces and it takes a while for it to be pulled again, effectively “bedding them” in that side. Meanwhile, the car felt all over the place.
This would not happen if you just swap them left to right.
I guess it all depends on the carcass, if it’s directional (A048’s?)
Hmmm, good point on the insurance.
Still, would like to give it a go and see what it feels like.
Let’s see if one day at any track there is a tyre services van that can do the swap for a few laps and then I come in and change it back again.
It’s not me who’s fast, it’s the car, he has a mind of it’s own
Or could it have been my “go fast shirt” (remember? the one with the flames?)
If you want my opinion… and I haven’t got a clue what i’m talking aboot… i’d guess wet-traction and insurance would be your only problems. Although it might also feel funny in th edry until you have settled the rubber in…
I was meaning as a test only on a trackday, seeing that I seem to be wearing the left tyres only…
I reckon we should get some of these racetrack owners and track-day organisers to arrange/allow some counter-clockwise days… could save us all a fortune or at least stop us all walking around with a stoop…
I had a disussion at Magny Cours with Simon Scuffham
My nearside was almost bald and offside ok
so I wanted to swap wheels just for the track day but the feelings where mixed
He convinced me not to try with the tread in reverse
But I dont see why you cant take the tyre of the rim and refit so you can use the tyres on opposite sides
JohnC
Designing a tyre tread which will operate equally well rotating in either direction inevitably involves compromises which limit ultimate performance in some respects.
Directional tyres, on the other hand, are designed to rotate in one direction only (indicated by a conspicuous arrow pointing in the direction of rotation on the sidewall along with the word “rotation”); so performance - wet grip, directional stability and handling - far from being compromised, is optimised.
Obviously, a directional tyre can deliver this improved performance only if it is correctly fitted to ensure that it rotates in the direction indicated on the sidewall.
What happens if you are unfortunate enough to have a puncture and your spare wheel is fitted with a directional tyre designed to rotate in the opposite direction to the tyre which it replaces? You are recommended to treat the spare wheel as a ‘Temporary spare’, drive at reduced speed and have the tyre correctly refitted as soon as possible.
(Reproduced by kind permission of the BRMA)
Oh and slicks are directional as well so I guess the construction is also designed to operate in one direction only - low speed OK but higher speed and forces could in theory I guess result in the tyre failing …
It cover your ass time - think Explorer, Ford and Firestone …
But Andy, I’m not talking real-world driving here, it’s for dry track use.
Bike (Dunlop) slicks are also directional (arrow and all) but after a few seasons racing I discoveded that some chap was using them the other way as well and said that there was no difference.
It turns out that the carcass was symmetrical, so if we take out the water-clearing properties (dry track) it was the same.
Now mounting them on the correct sense from one wheel to the other I mentioned before. It should be ok, but since the wear pattern has been set, they feel horrible, until they start to wear again wity that patter’s side. This includes rubber-pulling (you know, when the rubber gets hot and the forces are always in the same sense the tyre basically beds in to that position).
Just wondering if these brands’ marketing and lawyers are blindfolding us and the carcasses are really symmetrical.
I repeat, if not for water-clearing, if they were symmetrical, what could go wrong?
Uldis - just had a quick look but can’t quite place my hands on it now…but I actually have a small book that is just about tyres…with all sorts of interesting facts…anyway i remember reading about this and due to the tyre construction, the casing is actually made up of a number of layers laid across the across the tyre at a particular angle that best meets the design spec for the tyre, ie, lateral stiffness, ride quality etc. Therefore, if you reverse the tyre you place loading on these innner layers in a manner that they were not designed to take. Whilst this is bad in a brand new tyre it can be even worse with a tyre that has already been run in the correct direction as certain loadings have already been applied.
It may be a bad analogy, but if you bent a spoon you can still use it, but if you bend it back the other way it usually snaps!
What if the carcass cross threads were axactly symmetrical?
The rear tyres wouldn’t be a problem, as they do both forces equally: accelerating and decelerating.
The fronts would be a bit worrying, since they only brake now and the forces while reversed would be completely opposite.
I looked on a number of sites - including Yokohama and the information on directional tyres is very low - just what I posted - unles, as you say, its about water clearing properties - which makes sense …
I agree with your thinking, the problem is no manufacturer is saying how their tyre is constructed, which is why I mention the slick - when new why is there a direction - it can only be due to the construction it sure is not tread pattern !!
If slicks are rotational, then it is not just the tread pattern, and not related to dry or wet…
The tyres are computer modelled so that all the angles and stresses fall on the right components when the tyre is running under load, so if you run it the wrong way all the stresses are reversed and you are bound to get a failure sooner or later…
I understand what Uldis says about symetrical or not, but even if you cut the carcase open you would only be seeing the tyre when not under load…
I guess we could ask Gav on Saturday at Anglesey ??
What if the carcass cross threads were axactly symmetrical?
The rear tyres wouldn’t be a problem, as they do both forces equally: accelerating and decelerating.
The fronts would be a bit worrying, since they only brake now and the forces while reversed would be completely opposite.
So, are the cross threads symmetrical?
Uldis
What makes you think the front and rears would be a different construction - i wouldn’t think so. I also think that braking force must be just as mighty as accelerative force - esp with some daft mexican at the wheel - so feel that with a road tyre, surely the direction of rotation is to mainly ensure water dispersion and directional stability?? - I can’t explain it on a slick tho’
Anyone got more info to expand on what Andy says above. Can the others dig out their wee books and enlighten a thicko like me please…
