Thread: Tyre Rotation Diagonally - What's your Thoughts??

Greetings all,

When it comes to tyre rotation in any pattern other than front to rear, rear to front, and only on the same side, PLEASE do not reverse the rotation of the tyres after the first 500km of travel. And disregard any instructions on rotating the spare into service if it will mean the reversing the rotation of the tyre.

When new, the tyre sidewalls and cord plies are unstressed. After about 500 km of travel the tyres become stressed, which results in the cords and plies stretching, and the rubber/polymer/cords which hold the tyre together expand in one direction to their designed extent and size. These are what holds the tyre together in a radial manner - basically by the application of torque, a twisting force, which also places strain on the wire-and-rubber beads and the capping of the aramid or steel belts in the tread edge areas. It also places stress on the tread blocks and the sipes (the really thin 'cuts' in the tread area that basically suck the tyre down onto a wet surface).

Reversing the rolling direction of the tyre will cause the torque to be applied in the opposite direction, with potentially disastrous results including tyre delamination - the edges of the steel or aramid (soft woven form of Kevlar) belts can cut through the cords and plies and fly off. Note the occasional truck tyre coming apart on the highway at speed, as we've probably all seen. That is usually caused by either heat build-up due to low pressure, or a tyre has been rotated to the opposite side of a truck after being re-grooved or repaired.

This is why some tyres are marked with a rotation arrow from new (i.e. they are 'directional' tyres) - it's not just because the tread is shaped in a particular way, but because the design dynamics of the tyre require that the tyre assume a particular mode of deformation to ensure safety and stability.

What will happen if the tyre gets directionally reversed after its run-in period is that the cords binding the plies will stretch and weaken. Once this happens they will look like little bulges, typically about the size of a 50-cent coin and protruding up to several millimetres. The cords may snap completely and you will then have the traditional blowout - usually on the sidewall just below the tread/belt area. Not a comforting thought at 110 km/hr going down the freeway with two tons of LandRover and 3.6 tons of trailer into oncoming traffic.

Let me reiterate - PLEASE, for your own sake and that of every family on the road - PLEASE do not reverse the rotation of the tyres once they have been on the road from new for 500 kms or more. Ever. I've seen the aftermath and it ain't pretty. Writing reports for the insurance companies/police/coroner isn't fun either.

- Wayoutwest
Tyre and wheel specialist, 5 years at Bob Jane T-Marts, 2 years with Tyrepower, 2 years with Mullins Wheels, must have changed 50,000 tyres in that career.
Disco 2 auto trans with 2-in lift kit 1999, Disco 2 std 5-spd man trans 2001 - both 4.0 petrol V8. Part-time A/T driving instructor.

Originally Posted by Wayoutwest

Greetings all,

When it comes to tyre rotation in any pattern other than front to rear, rear to front, and only on the same side, PLEASE do not reverse the rotation of the tyres after the first 500km of travel. And disregard any instructions on rotating the spare into service if it will mean the reversing the rotation of the tyre.

When new, the tyre sidewalls and cord plies are unstressed. After about 500 km of travel the tyres become stressed, which results in the cords and plies stretching, and the rubber/polymer/cords which hold the tyre together expand in one direction to their designed extent and size. These are what holds the tyre together in a radial manner - basically by the application of torque, a twisting force, which also places strain on the wire-and-rubber beads and the capping of the aramid or steel belts in the tread edge areas. It also places stress on the tread blocks and the sipes (the really thin 'cuts' in the tread area that basically suck the tyre down onto a wet surface).

Reversing the rolling direction of the tyre will cause the torque to be applied in the opposite direction, with potentially disastrous results including tyre delamination - the edges of the steel or aramid (soft woven form of Kevlar) belts can cut through the cords and plies and fly off. Note the occasional truck tyre coming apart on the highway at speed, as we've probably all seen. That is usually caused by either heat build-up due to low pressure, or a tyre has been rotated to the opposite side of a truck after being re-grooved or repaired.

This is why some tyres are marked with a rotation arrow from new (i.e. they are 'directional' tyres) - it's not just because the tread is shaped in a particular way, but because the design dynamics of the tyre require that the tyre assume a particular mode of deformation to ensure safety and stability.

What will happen if the tyre gets directionally reversed after its run-in period is that the cords binding the plies will stretch and weaken. Once this happens they will look like little bulges, typically about the size of a 50-cent coin and protruding up to several millimetres. The cords may snap completely and you will then have the traditional blowout - usually on the sidewall just below the tread/belt area. Not a comforting thought at 110 km/hr going down the freeway with two tons of LandRover and 3.6 tons of trailer into oncoming traffic.

Let me reiterate - PLEASE, for your own sake and that of every family on the road - PLEASE do not reverse the rotation of the tyres once they have been on the road from new for 500 kms or more. Ever. I've seen the aftermath and it ain't pretty. Writing reports for the insurance companies/police/coroner isn't fun either.

- Wayoutwest
Tyre and wheel specialist, 5 years at Bob Jane T-Marts, 2 years with Tyrepower, 2 years with Mullins Wheels, must have changed 50,000 tyres in that career.
Disco 2 auto trans with 2-in lift kit 1999, Disco 2 std 5-spd man trans 2001 - both 4.0 petrol V8. Part-time A/T driving instructor.

Excellent post - and exactly why I don’t do the rotation.
Leave them spinning the way they “bedded in”

Originally Posted by Wayoutwest

Greetings all,

When it comes to tyre rotation in any pattern other than front to rear, rear to front, and only on the same side, PLEASE do not reverse the rotation of the tyres after the first 500km of travel. And disregard any instructions on rotating the spare into service if it will mean the reversing the rotation of the tyre.

When new, the tyre sidewalls and cord plies are unstressed. After about 500 km of travel the tyres become stressed, which results in the cords and plies stretching, and the rubber/polymer/cords which hold the tyre together expand in one direction to their designed extent and size. These are what holds the tyre together in a radial manner - basically by the application of torque, a twisting force, which also places strain on the wire-and-rubber beads and the capping of the aramid or steel belts in the tread edge areas. It also places stress on the tread blocks and the sipes (the really thin 'cuts' in the tread area that basically suck the tyre down onto a wet surface).

Reversing the rolling direction of the tyre will cause the torque to be applied in the opposite direction, with potentially disastrous results including tyre delamination - the edges of the steel or aramid (soft woven form of Kevlar) belts can cut through the cords and plies and fly off. Note the occasional truck tyre coming apart on the highway at speed, as we've probably all seen. That is usually caused by either heat build-up due to low pressure, or a tyre has been rotated to the opposite side of a truck after being re-grooved or repaired.

This is why some tyres are marked with a rotation arrow from new (i.e. they are 'directional' tyres) - it's not just because the tread is shaped in a particular way, but because the design dynamics of the tyre require that the tyre assume a particular mode of deformation to ensure safety and stability.

What will happen if the tyre gets directionally reversed after its run-in period is that the cords binding the plies will stretch and weaken. Once this happens they will look like little bulges, typically about the size of a 50-cent coin and protruding up to several millimetres. The cords may snap completely and you will then have the traditional blowout - usually on the sidewall just below the tread/belt area. Not a comforting thought at 110 km/hr going down the freeway with two tons of LandRover and 3.6 tons of trailer into oncoming traffic.

Let me reiterate - PLEASE, for your own sake and that of every family on the road - PLEASE do not reverse the rotation of the tyres once they have been on the road from new for 500 kms or more. Ever. I've seen the aftermath and it ain't pretty. Writing reports for the insurance companies/police/coroner isn't fun either.

- Wayoutwest
Tyre and wheel specialist, 5 years at Bob Jane T-Marts, 2 years with Tyrepower, 2 years with Mullins Wheels, must have changed 50,000 tyres in that career.
Disco 2 auto trans with 2-in lift kit 1999, Disco 2 std 5-spd man trans 2001 - both 4.0 petrol V8. Part-time A/T driving instructor.

Great to hear from someone in the industry in regards to rotating tyres diagonally... I've always tried to at least rotated my tyres Front<>Rear every 5000kms but I also have rotated diagonally after advice from wheel Aligners in an effort to try and flatten out any feathering on the tyre edges and over the years I've fortunately have never experienced any blowouts. It's always bothered me mainly due to the increase in tyre noise but it was a necessary thing to do to get the best mileage out of the tyres on our previous Prado. Apparently I was told that they were renowned for wearing the outer edges of tyres...

Just curious here in regards to directional tyres... I've noticed with some tyres that they have raised lettering on "only one side" of the tyre... I assume with directional tyres that there would be the same raised lettering on "both sides" of the tyre to allow for the tyre to rotate in the required direction and also display the same raised lettering (if u know what I mean)?

Roll the dice if you buy s/hand tyres.

Originally Posted by Robmacca

Great to hear from someone in the industry in regards to rotating tyres diagonally... I've always tried to at least rotated my tyres Front<>Rear every 5000kms but I also have rotated diagonally after advice from wheel Aligners in an effort to try and flatten out any feathering on the tyre edges and over the years I've fortunately have never experienced any blowouts. It's always bothered me mainly due to the increase in tyre noise but it was a necessary thing to do to get the best mileage out of the tyres on our previous Prado. Apparently I was told that they were renowned for wearing the outer edges of tyres...

Just curious here in regards to directional tyres... I've noticed with some tyres that they have raised lettering on "only one side" of the tyre... I assume with directional tyres that there would be the same raised lettering on "both sides" of the tyre to allow for the tyre to rotate in the required direction and also display the same raised lettering (if u know what I mean)?

Okay, time for tyre wear 101.

First, the raised lettering thing. They're raised on one side because, when they are initially fitted, some people don't like having raised lettering, so the fitters will mount the letters to the inside. Unless the tyre has been designed and manufactured as a directional tyre (it will have a raised arrow and the words 'direction of rotation' or similar) it doesn't matter, as it's a new tyre fitment and hasn't been driven on sufficiently to have its direction of rotation established. Once established (i.e. more than about 500km - or doing burnouts) it matters. So whether the raised lettering is on the inside or the outside has no effect on balance or anything else - it's purely aesthetic.

Second, wear patterns. Many AWD vehicles use a live rear axle and some have both live. Wear at the rear wheels is controlled by two main factors - pressure and load. For some reason - usually either ride comfort and noise, or the vehicle manufacturer's fear that there will be insufficient pressure in the tyres when the vehicle gets loaded or unloaded - vehicle manufacturers tend to specify a higher pressure in the rear tyres than in the front pair. WTF? The front end is carrying most of the weight of the vehicle in day-to-day driving (engine, transfer case, gearbox etc), so it stands to reason that there should be more pressure in the front tyres than the rear. So those handy-dandy tyre pressure placards attached to the vehicle or listed in the handbook are just plain WRONG unless the vehicle is four-up with full fuel and nearly maxed-out luggage. In any other load condition, you will experience abnormal wear.

So, let me introduce my dear and gentle readers to an old tyre-fitter's Rule Of Thumb. Literally. For all vehicles - and I'm listing everything from ride-on mowers to Super Singles and the tyres on a Mack and 20 ton (which I also drive occasionally) - the rule of thumb is applicable for any vehicle and any amount of load up to the vehicle maximum. Forget tyre pressure gauges, few of which are accurate anyway. With the vehicle on a hard surface, spread your thumb and forefinger to maximum extent, which for most adults will be about 7.25 to 7.5 inches. Place the Rule of Thumb against the 'contact patch' - the area of rubber actually in contact with the ground. They should match. Irrespective of load, brand of tyre, type of wheel or any other factor, if you have that much contact patch, you are at the correct pressure for the load condition of your vehicle - empty, lightly loaded, half-loaded, trailer attached or not, fully maxed out.

Third, abnormal wear patterns. Unless you're a big fan of power steering and turning your wheels whilst stationary, if a tyre looks like it's got lots of little flat spots, chances are that your springs and dampers ('shock absorbers') are mismatched, so following hitting a bump on the road, the spring absorbs the initial upthrust and pushes the tyre back in contact with the road; dampers change the speed of travel of the downthrust of the spring. If the dampers are worn (typically about every 40k, but possibly as little as 25k depending on your road surfaces mix), or the springs are hard/soft/worn or otherwise mismatched, the tyre actually skips and skids as it re-makes contact with the solid surface, causing a minute 'flat spot' on the tyre. This gets accentuated over time until the 'flat spots' become pronounced and semi-permanent. You can fix this by more frequent rotation front-to-rear and rear-to-front (since this tends more to happen to front tyres due to additional movement in the steering and front suspension geometry), and maybe a SLIGHT increase in tyre pressure, or more seriously by getting your spring and damper rates checked and matched at a reliable suspension place (I've used Pedders in the past, but I'm sure there are others) and be prepared to buy a new set of dampers (or, for old and well-thrashed vehicles, new springs as well). If your tyres have serious and blindingly obvious flat spots, you can even get them machined back to round again - although few tyre services actually have the equipment, so you might have to look around (used to use these back when retreads were a thing). It can be worth it to salvage a nearly-new set of tyres. Getting your spring and damper rates checked is definitely worth it. Some places offer it for free - look around. And don't forget the steering damper.

Fourth, balance. Most tyre services provide very accurate electronic wheel balancing. However, many of them use a centre-mount (a single cone mounting through the centre-hole of the wheel). Usually this is okay, but if the wheel manufacturer was a tad inaccurate in constructing the wheel (whether alloy or pressed steel), it may be a millimetre or two off, compared to the wheel lug holes' placement. The trick, if you have experienced vibration through the steering wheel or the body, is to request a 'stud-pattern balance', so they mount the wheel on the balancer in the same manner as it's mounted on the vehicle - through the lug holes. It may cost a couple of bucks extra per wheel, but worth it if the problem is eliminated. If you still have balance issues after that, some places also have an 'on-car balancer' which can be requested. Usually, however, if you get to this level, it means your brake rotors/drums are out of round, so you may need to look deeper into the mechanicals. Vibration through the vehicle body and/or steering wheel at speeds above about 75 km/hr generally indicates rear wheel balance issues; below that, or vibration only in the steering wheel, it's generally front wheel balance issues, or steering damper/Pitman arm/tie rod issues.

Fifth, alignment. Live front axle 4WDs (and in particular, early Pajeros and some Land Cruisers), apart from having their axles slightly offset, often have little to no camber and/or caster adjustment, although basic shimming in one direction or another may be available. What little adjustment you may get is through tie rod adjustment and/or re-packing/-tightening front bearings. Some Japanese makes intentionally had an out-of-true axle housing set (for left-hand drive) to compensate for drivers bashing into gutters whilst parking. For us, driving on the other side of the road, all this caused was excess outer LF tyre wear, because they only made the one axle housing for worldwide use. Some aftermarket kits are available for certain marques that incorporate caster and camber adjustment where not provided by the manufacturer. In extreme cases it may be necessary to visit a Truck and Bus Alignment Centre to have the front axle pressed into alignment.

Anyway, enough for one lesson. If you take away anything from this post, the Rule Of Thumb is simple, practical, and adequate.
Hope this helps.
- Wayoutwest.

I think that this; "you must rotate the tyres regularly" may be a carry over from old bias belted tyres, added to what your father told you!

It is much more critical to maintain the correct pressures for the load, and the state of the suspension and wheel alignment.

Originally Posted by Wayoutwest

Greetings all,

When it comes to tyre rotation in any pattern other than front to rear, rear to front, and only on the same side, PLEASE do not reverse the rotation of the tyres after the first 500km of travel. And disregard any instructions on rotating the spare into service if it will mean the reversing the rotation of the tyre.

When new, the tyre sidewalls and cord plies are unstressed. After about 500 km of travel the tyres become stressed, which results in the cords and plies stretching, and the rubber/polymer/cords which hold the tyre together expand in one direction to their designed extent and size. These are what holds the tyre together in a radial manner - basically by the application of torque, a twisting force, which also places strain on the wire-and-rubber beads and the capping of the aramid or steel belts in the tread edge areas. It also places stress on the tread blocks and the sipes (the really thin 'cuts' in the tread area that basically suck the tyre down onto a wet surface).

Reversing the rolling direction of the tyre will cause the torque to be applied in the opposite direction, with potentially disastrous results including tyre delamination - the edges of the steel or aramid (soft woven form of Kevlar) belts can cut through the cords and plies and fly off. Note the occasional truck tyre coming apart on the highway at speed, as we've probably all seen. That is usually caused by either heat build-up due to low pressure, or a tyre has been rotated to the opposite side of a truck after being re-grooved or repaired.

This is why some tyres are marked with a rotation arrow from new (i.e. they are 'directional' tyres) - it's not just because the tread is shaped in a particular way, but because the design dynamics of the tyre require that the tyre assume a particular mode of deformation to ensure safety and stability.

What will happen if the tyre gets directionally reversed after its run-in period is that the cords binding the plies will stretch and weaken. Once this happens they will look like little bulges, typically about the size of a 50-cent coin and protruding up to several millimetres. The cords may snap completely and you will then have the traditional blowout - usually on the sidewall just below the tread/belt area. Not a comforting thought at 110 km/hr going down the freeway with two tons of LandRover and 3.6 tons of trailer into oncoming traffic.

Let me reiterate - PLEASE, for your own sake and that of every family on the road - PLEASE do not reverse the rotation of the tyres once they have been on the road from new for 500 kms or more. Ever. I've seen the aftermath and it ain't pretty. Writing reports for the insurance companies/police/coroner isn't fun either.

- Wayoutwest
Tyre and wheel specialist, 5 years at Bob Jane T-Marts, 2 years with Tyrepower, 2 years with Mullins Wheels, must have changed 50,000 tyres in that career.
Disco 2 auto trans with 2-in lift kit 1999, Disco 2 std 5-spd man trans 2001 - both 4.0 petrol V8. Part-time A/T driving instructor.

Seems strange to me. Tyres have torque applied in both directions, more consistently in the drive direction and more aggresively in the opposite direction when braking, so you would think that would mean then that you should rotate diagonally for a RWD for example?

I had a look to see what the tyre manufacturers recommend and of all of the manufacturers that I checked, they all recommended crossing tyres diagonally assuming they were all the same size and not directional. Pirelli recommended whatever the manufacturer of the vehicle says.

Car Frequently Asked Question | Michelin Tyres Australia
Why Rotate Your Car Tyres? Tyre Rotation Guide | Dunlop Tyres
How To Rotate Your Tyres For Best Wear | Goodyear Tyres
Tire Rotation: How and Why to Rotate Your Tires | Bridgestone Tires
Rotating Your Tyres - Cooper Tires Australia | Tyres Worth Owning
https://www.yokohamatire.com/tires-1...-and-balancing
https://www.bfgoodrichtires.com/main...erotation.html
https://www.youtube.com/watch?v=P42kRgRCm1g for Falken Tyres
https://www.hankooktire.com/global/t...rotation.html#
https://www.kumhotire.com/us/cont/co...enuCd=MN000183

and a couple of shops that showed

https://www.tyrepower.com.au/tyres/t.../tyre-rotation
https://www.jaxtyres.com.au/knowledg.../tyre-rotation
https://www.racq.com.au/cars-and-dri.../tyre-rotation
https://www.tyroola.com.au/guides/tyre-rotation/

Tyre wear is also due to where the vehicle is driven, and how it is driven.
Around town with lots of roundabouts, right turns, the left front will always wear quicker, and rotation is a must.
We find this with our work vans.
Mainly country running,rotating isn't needed.