[Goldfish_8]

Mr tyre guru sir, normally at around 6000 miles or so I have the fronts and backs swapped to even up the wear, and everything is ok. When this is done its off side front is swapped with the off side rear and near side front with near side rear.

Due to the number of roundabouts over here in the uk, the outside edge of the nearside tyres and the inside edge of the off side tyres are showing more signs of wear than the opposite edges. The tyres are Falken FK912 assymetircs (225/40 18). Would it be okay to swap the nearside front with the offside rear and the off side front with the near side rear to even up the edge wear.

Normally

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Would this be okay

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Thanks

Mark

[Dazzler]

Hi Mark,

I'm sure Trev will appear soon to answer your query...Love your use of symbols to illustrate your question (Brilliant) 

[Surferdude]

Hi Mark. The short answer is "yes".

I assume from your post that by "nearside" you are referring to the left hand side. Which is correct BTW. "Nearside" refers to near the curb but many people call the right hand side "nearside" as it's near the driver.

We have at least as many roundabouts here in Austraila. In fact, my whole suburb does not have a single traffic light, but I traverse 12 roundabouts from the main road in the adjoining suburb to get to my house.

One thing though. It may be symptomatic of the 18" tyres (or your driving - not a criticism, just an observation) but whilst I would expect more outside shoulder wear on the LHS ( and more on the front than the rear), I haven't seen the inside wear on the right hand side you are referring to. Normally when you are cornering, even hard, there is little weight on the inside tyres so the wear factor shouldn't be noticeable.

It may be worth having a wheel alignment check just to be sure it's OK.

Of course it's all reversed in Europe and North America.

[2i30s]

if the tyres are directional, you cant swap them from left to right,only front to back. 

[Dazzler]

if the tyres are directional, you cant swap them from left to right,only front to back. 

Not unless you are going to drive everywhere in reverse 

[Surferdude]

if the tyres are directional, you cant swap them from left to right,only front to back.  

They're asymetrical not directional.
They can be swapped from side to side


  God! Haven't I taught you guys ANYthing?

http://www.toyo.com.au/Tyre%20Tips_2_Tyre%20Rotations.htm

[Talking Hoarse]

I am all for swapping wheels from front to back so as to even out the wear etc. 
However I do not swap from one side to other as I understand that tyres "run in" to their direction of travel, and if that is reversed (by swapping sides) then it will need to wear in again and I have previously found often need rebalancing.
Also, I have sometimes found that if a tyre has worn on a shoulder (often the outer shoulder of front tyres) then even if it is moved to the back where the tyres wear evenly then it continues to wear the shoulder, although of course rear tyres should wear very much less on fwd cars.
I think it is best to make sure the tracking is right, and keep the tyre pressures right (I favour them quite hard on my i30 -- have settled at 36psi all round on 16" wheels).

[Surferdude]

Hi Talking Hoarse,
Your concern about reversing the direction of travel of radial tyres is a furphy which has persisted in the tyre industry since the introduction of radials.
It is totally incorrect, so you don't need to worry about it.
In normal service, tyres are not subject to any carcass altering stress and if they were, belt separation would occur quickly. The biggest stresses applied to a carcass are during acceleration, but these are offset (more than) by braking.
Hope this helps clarify this for you and any others on here who may have heard the same story.

Concerning the need to rebalance, this is pretty normal anyway when moving tyres from the back to the front because any minor imbalance will be more noticeable on the front. You feel front wheel imbalance through the steering wheel. Rear wheel imbalance makes its presence felt through your seat.

And putting a tyre on the back with a worn shoulder won't as you sayput the missing rubber back, but it will lengthen the life of the tyre because most of the weight will be on the tread area with the most tread remaining and rear tyres aren't subject to the same distortion when turning so the uneven wear will be negated.
If you have the time, go and park your car on a flat piece of concrete and turn your wheels onto full lock and get out and look at the angle (camber) of the wheel. You'll see clearly how much distortion can be caused.

[2i30s]

if the tyres are directional, you cant swap them from left to right,only front to back.  

They're asymetrical not directional.
They can be swapped from side to side


  God! Haven't I taught you guys ANYthing?

http://www.toyo.com.au/Tyre%20Tips_2_Tyre%20Rotations.htm

yes,but your the tyre guru not me. 

[agentr31]

If you have the time, go and park your car on a flat piece of concrete and turn your wheels onto full lock and get out and look at the angle (camber) of the wheel. You'll see clearly how much distortion can be caused.

akermanns angle?

[Surferdude]

If you have the time, go and park your car on a flat piece of concrete and turn your wheels onto full lock and get out and look at the angle (camber) of the wheel. You'll see clearly how much distortion can be caused.

akermanns angle?

No. It's more the camber. There is a term but I forget what it is.

[agentr31]

lol i thought that term was akermanns angle... where as you turn the steering it gains some camber so the wheel is turning on a point not the whole contact patch? or have i got it wrong?

commadores do it really bad turn the wheel and it looks like it has about 5 degrees of camber...

[2i30s]

is it called sai,steering angle increment?

[Surferdude]

lol i thought that term was akermanns angle... where as you turn the steering it gains some camber so the wheel is turning on a point not the whole contact patch? or have i got it wrong?

commadores do it really bad turn the wheel and it looks like it has about 5 degrees of camber...

I think ackerman's angle is also called toe out on turns - one wheel will be at a different angle from the straight ahead, to the other to offset the difference in speed between the inside and outside wheel when on lock. I'll dig out my old manual and see what I can find. It's all so long ago.

[Surferdude]

is it called sai,steering angle increment?

Pretty sure you're right with the acronym but it stands for "Steering Axis Inclination". In th eold days "KPI" or King Pin Inclination.
You'll be amazed how much rubber you can wear off the edge of your tyres if your car has a lot of negative or positive SAI.
We used to take a car out onto the concrete driveway and put it on full lock and drive around in a circle. No matter how slowly you go (even slipping the clutch), you'd leave a rubber circle where you'd been.
Most cars have either negative or positive SAI. It's designed into the suspension for several purposes. But IIRC it basically helps centre the steering after you've completed a turn.

For the technically minded of you, this is about the simplest and easiest to read I can offer you.

http://www.anewtoronto.com/wheel%20alignment.html

[agentr31]

LOL i would hate to see the maxima do that... meduim sized FWD with -ive camber... would leave impressive circles!

..But IIRC it basically helps centre the steering after you've completed a turn.

My very basic understanding tells me that it's the caster that (predominantly at least) does that. Think about riding your bike hands-free, it rides straight while upright but turns towards the "camber" as you move weight side-to side. This suggests that camber in itself promotes turning rather than turning-correction.

In fact if you look at a motorcyclist leaning into a corner under power the wheel is sometimes actually turned (out) against the turn to prevent the bike turning in too tightly. Stretching this a little it's possible to see that when a bike is turning a corner (and the lean is just right) it is really going in a straight line. Ever flown a plane? Turns are done the same way... essentially once you bank all the controls are neutralised.

Cars defy all this in an attempt to maintain their tyres square to the road.  All this to avoid the passengers tipping... hang on, if we tipped the car instead, the passengers would not tip at all.  Next generation cars maybe... 

 

[Goldfish_8]

Thanks for the replies chaps, I had another look at the tyres today, and think the edges will survive no more than another 3000-3500 miles. Just on about 4.5mm tread in the main tread pattern. (Covered about 13400 miles since fitted back in January)

Yup, correct nearside = curbside, not come across it referring to the drivers side.

The inner edge wear is due to the old lowering springs, which have added about 1.10 minutes of negative camber to the set up, and with the standard suspension mounting points that can't be dialed out. Would need to add pillow ball mounts to the top of the struts to sort that.

When I had an Impreza WRX with PPP, that was on the same size tyres (225/40 18), again with lowering springs, but that set up could be altered to reduce the negative camber.

I think I will have to look at a tyre slightly higher up the food chain to get better wear. (And probably 4 new wheels again, as the MS Design alloys are quite soft and all four have flat spots on the inner edge again!)

Thanks

Mark

[Surferdude]

..But IIRC it basically helps centre the steering after you've completed a turn.

My very basic understanding tells me that it's the caster that (predominantly at least) does that. Think about riding your bike hands-free, it rides straight while upright but turns towards the "camber" as you move weight side-to side. This suggests that camber in itself promotes turning rather than turning-correction.

Yes pip, you're right but SAI also contributes to it. Because it does excatly what you were saying. Cars try to kkep the tyre flat on the road. SAI lifts it up on a corner and the natural weight transfer as you straighten up helps pull the car back straight.