Static, dynamic, tolerance or whatever the fact remains the tyres are wearing!

Yep,

and therefore the manufacturers settings are a guide only and the correct wheel alignment settings should be achieved by analysis of the tyre wear patterns & questioning the owner about driving style, how much cargo they carry, how often they check the tyre pressures & what tyre pressure they use, etc.

Why is it that so many mechanics have reduced themselves to the role of computer interrogator & parts replacer? Don't they do diagnostics anymore?

OP: The reason your steering wheel is crooked is because the lazy git that adjusted just adjusted one side only.

Looking at those settings, I'd guess the operator knew how to use the machine but didn't really know how to do a wheel alignment.

Had the wife's fiesta down in the tyre place. The outside of the front left wore badly. I got them to put new tyres on the rear and old ones on the back. I asked them to check the tracking, he said it was green on the PC. I can't figure out why with the level of wear :(.

This is a topic from wim regarding settings maybe it will help?

.........................................................

The simple answer is that there is no such thing!

Seeking the perfect set-up is dependent on variables that exceed even the most experienced in the industry, F1 with millions invested each season still cannot deliver 'matter of fact' positions, so what do you do? how can anyone establish the perfect set-up.

First lets look at the manufacture

Geometry within new models tends to be an extension of previous established positions, minor tweaks to accommodate suspension travel, wider tyres and so on is often visible and do fall into the 'safe zone', but attempt to manufacture a completely new Geometry then things can go very wrong, as it did for the Nissan 350Z and the new Peugeot 1002.

So now your modified

Taken from the above the car had recognized Geometric positions and is now modified... suspension, tyres, turbo but now things just don't feel right, well maybe understanding the 'forces' involved within Geometry not just the name of the angles could help.

Toe: exerts no force unless violated to the maximum since the chosen position 'Dynamically' is 0

Camber: exerts a 'conical' force and will want to roll into the lowest point of the imaginary cone, the force adds security to straight line travel and compensates for body roll.... excessive camber will make the steering heavy and lazy (turn out) due to the 'compressive' force generated from the angular position of the imaginary cone.

Castor: exerts a non-reactive longitudinal force assuming the positions over the axle are within manufactured tolerances, on cornering the Castor contributes toward displacement of the steering axis and the position of the 'scrub radius' this force is very important.

KPI/SJI: exerts a very high force toward directional stability, this force is immediately detectable if any attempt is made to deviate from straight line travel... the force is generated by 'inclining' the pin during any steering action, this inclination lifts the vehicle and adds weight on the pin, in reply the equilibrium through the rack will return the steering so the KPI can relax.

How to develop your own positions

First consider your reasons, what do you expect from the car and to what end, is tyre wear an issue, are the modifications cosmetic or deliberate? The four examples shown reflect the most common consequences of modifying a car, in particular lowering, the forces displayed need to be examined in your own example and explored.

It could be easy to assume now that all things 'Geometrical have been covered?

Further reading:-

Scrub radius

Ackermann theory

Delta curve

Bump steer

Thrust angle

Camber curve

Over/under steer

Tyre slip angle/resistance/trail

Lock angles

Cradle symmetry

Memory steer

Castor trail

Cars have never been so complex.........

It'll be booked into a non-Skoda specialist alignment centre next week. W'll see what happens.

Steve

Static, dynamic, tolerance or whatever the fact remains the tyres are wearing!

Recognizing the static figures may be wrong suggests a much better solution to complaint than "it's within" all should be well?

If we can agree on that then we could look at the dynamics, add a smattering of tolerance and conclude a solution don't you think?

What many fail to see is the manufacturers settings are "suggestions" not law. The human variables are to vast to suggest an absolute, matter of fact calibration for any car...... That's why there's not 21 drivers on the F1 podium after the race.

We are talking about a mass-produced family car here, not an F1 car. The manufacturer figures are not 'suggestions', they are 'optimum' settings that have been arrived at by a team of engineers testing cars day in, day out. I used to work for MIRA (Motor Industry Research Association) and they do this work (under contract) for many of the major car manufacturers. Cars would be instrumented, and then tested on the various tracks, split-u surface etc etc. G-forces measured and handling bias of the car evaluated. Eventually optimum settings are established.

For a standard road-going car it will be absolutely fine so long as it is within tolerance. You have no means of determining what the dynamic settings are unless you have some fairly specialist kit bolted to the chassis with the car on the road.

It is possible to improve upon the manufacturer settings for particular driving circumstances (e.g. track) but without specialist kit this will involve trial and error (make a change, try the car on the track and see how it is, make another change etc etc). The average driver does not have the time or money to do this.

My advice is that if the car is properly set to manfr spec and suffering abnormal tyre wear or handling problems then look for worn or defective suspension components that are allowing the wheels to move abnormally when under load. Also look for chassis tweak etc (although decent alignment kit should pick this up).

If the car is modified then to an extent the owner is on his own. Start with standard manfr spec and then it will be a process of trial and error.

We are talking about a mass-produced family car here, not an F1 car. The manufacturer figures are not 'suggestions', they are 'optimum' settings that have been arrived at by a team of engineers testing cars day in, day out. I used to work for MIRA (Motor Industry Research Association) and they do this work (under contract) for many of the major car manufacturers. Cars would be instrumented, and then tested on the various tracks, split-u surface etc etc. G-forces measured and handling bias of the car evaluated. Eventually optimum settings are established.

For a standard road-going car it will be absolutely fine so long as it is within tolerance. You have no means of determining what the dynamic settings are unless you have some fairly specialist kit bolted to the chassis with the car on the road.

It is possible to improve upon the manufacturer settings for particular driving circumstances (e.g. track) but without specialist kit this will involve trial and error (make a change, try the car on the track and see how it is, make another change etc etc). The average driver does not have the time or money to do this.

My advice is that if the car is properly set to manfr spec and suffering abnormal tyre wear or handling problems then look for worn or defective suspension components that are allowing the wheels to move abnormally when under load. Also look for chassis tweak etc (although decent alignment kit should pick this up).

If the car is modified then to an extent the owner is on his own. Start with standard manfr spec and then it will be a process of trial and error.

That's exactly what i said in different terminology. My realm is "consequence" not design so i'm sorry i have to disagree with the "optimum settings" statement, at best it's theoretical settings.

If things were so perfect then this thread "Enormous and dangerous wear on the insides of my rear tyres" wouldn't exist, ever more since the positions are within "manafatures tolerance".

Optimum settings and suggestions are the same thing depending on which side of the fence you stand on, in this case like many others the manufacturer's settings don't work.

Please believe me i'm not having a pop but the fast fit industry thinks the OEM data is law meaning owners in distress like this one are stranded wondering how the hell to resolve the problem.

I also want to display this thought..... Our cars components live in three realms

1: new

2: worn

3: knackered

The longest duration is "worn", no particular part needs replacing but collectively there is wear. Visible tyre wear would come from #3, slight wear from #2, the reason the car has adjusters is to correct #2!

We are talking about a mass-produced family car here, not an F1 car. The manufacturer figures are not 'suggestions', they are 'optimum' settings that have been arrived at by a team of engineers testing cars day in, day out. I used to work for MIRA (Motor Industry Research Association) and they do this work (under contract) for many of the major car manufacturers. Cars would be instrumented, and then tested on the various tracks, split-u surface etc etc. G-forces measured and handling bias of the car evaluated. Eventually optimum settings are established.

For a standard road-going car it will be absolutely fine so long as it is within tolerance. You have no means of determining what the dynamic settings are unless you have some fairly specialist kit bolted to the chassis with the car on the road.

It is possible to improve upon the manufacturer settings for particular driving circumstances (e.g. track) but without specialist kit this will involve trial and error (make a change, try the car on the track and see how it is, make another change etc etc). The average driver does not have the time or money to do this.

My advice is that if the car is properly set to manfr spec and suffering abnormal tyre wear or handling problems then look for worn or defective suspension components that are allowing the wheels to move abnormally when under load. Also look for chassis tweak etc (although decent alignment kit should pick this up).

If the car is modified then to an extent the owner is on his own. Start with standard manfr spec and then it will be a process of trial and error.

I'll be honest, I haven't done a paid wheel alignment for 20 years & my equipment was a light aligner...... but the theory doesn't change and experience counts for lots - I used to do between 10-20 alignments per day as a contractor. If I got them wrong I had to waste my own time fixing them free, so you tried to get it right the first time.

Our biggest problem was that most imported cars came setup for the country of origins roads and most Aussie roads had quite severe camber on them. This caused some very weird tracking problems & tyre wear issues. We also had problems with excessively low OEM spec tyre pressures (steel belt radials were only a few years on the market by then).

The end result was that often you had to re-invent (where possible) the wheel alignment and tyre pressure specs. We were one of the few alignment shops in the area that insisted on seeing the old tyres before attempting alignment. We had our own (nothing like factory) setting for Mercedes S-Class and other problem vehicles, had "special tricks" for vehicles with torsion bars & a regular clientelle that drove 2-3 hours to come & see us. We had many clients who had resigned themselves to buying tyres every 10,000km because they had been told their car was within tolerance & therefore nothing could be done.

Probably I'd still be doing alignments & suspension work except one of my clients offered me a job fixing aeroplane components with a substantial increase in $$$ (which consequently lead me down another career path).

My point? Factory settings are great if the car is just like it came from the factory but after about 40,000km the factory specs are a starting point & no longer gospel and the individual circumstances of car & driver have to be taken into account.

When the first Opel bodied Holden Commodores were introduced in Australia in 1978 the front camber was -1.5 degrees which was great at first but after a short while the European designed but Australian tuned front end couldn't handle the weight of the 3.3L cast iron straight 6 or the 5L cast iron V8 that was fitted. The front end had excessive vertical movement & the inside of the tyres would wear and the car would pull left. The fix was to knock the camber back to -1L/-0.75R and add more castor offset on the L. Suprise, suprise - the new model came out with factory specs similar to what we'd been using because somebody had got it wrong despite all their testing. It appears the rear end of the Skoda might be similar.

That's exactly what i said in different terminology. My realm is "consequence" not design so i'm sorry i have to disagree with the "optimum settings" statement, at best it's theoretical settings.

If things were so perfect then this thread "Enormous and dangerous wear on the insides of my rear tyres" wouldn't exist, ever more since the positions are within "manafatures tolerance".

Optimum settings and suggestions are the same thing depending on which side of the fence you stand on, in this case like many others the manufacturer's settings don't work.

The A5 platform has been manufactured in vast numbers and there has now been ample time for feedback to the factory on problems such as excessive tyre wear (indeed the factory have revised the rear camber settings).

For a car with relatively low mileage my suggestion would be to look for worn/defective/damaged components rather than go on a wild goose chase adjusting settings away from those specified by the manufacturer.

If many thousands of Octavias are running OK with the manufacturer specs without severe rear tyre wear then why should this particular example be any different? Any set up is only as good as the operator and equipment of course - who's to say that the calibration of the alignment kit was not a bit out?

Incidentally, I am speaking from the perspective of some years experience of chassis development (I was a development engineer at MIRA for a good few years).

Had the wife's fiesta down in the tyre place. The outside of the front left wore badly. I got them to put new tyres on the rear and old ones on the back. I asked them to check the tracking, he said it was green on the PC. I can't figure out why with the level of wear :(.

Some interesting reading there. in our case the car is mid 2006 with 23k on it. Its unmodified and not driven too hard by my other half. Will have to take a closer look. The good thing is that it ain't a brand new tyre on the front so worst case senario we won't be wrecking a new tyre.

Some interesting reading there. in our case the car is mid 2006 with 23k on it. Its unmodified and not driven too hard by my other half. Will have to take a closer look. The good thing is that it ain't a brand new tyre on the front so worst case senario we won't be wrecking a new tyre.

A lot of these tyre places only check the front toe setting. You really need a full alignment check and careful check over of suspension components for damage/wear etc.

I'd love to but it's a co. car and the Lease company only have accounts with the main dealers or ATS. Rock and a hard place. I'm considering taking it to Buckley Tyres in North Wales though and paying out of my own pocket.

However, I now have conflicting info. Is the camber, toe or caster adjustable at the rear of an Octavia. The link above suggests it is, but other threads say not and my Skoda Dealer say it isn't and they couldn't possibly have messed up the settings on the car:mad:

Steve

I had this on a Honda Integra - Got a new pair of tyres on the rear down to 2 mm in about 5k miles.

Tyre place said "you need main dealer" - main dealer said "lease co won't let us do anything tyre related"

In the end I rang up the lease co and said, "I'm doing 30k miles a year and I'm wearing tyres out in 5k. They cost £300/set, that's £1800/year. Would you like to arrange an alignment check for me?"

They did.

The A5 platform has been manufactured in vast numbers and there has now been ample time for feedback to the factory on problems such as excessive tyre wear (indeed the factory have revised the rear camber settings).

For a car with relatively low mileage my suggestion would be to look for worn/defective/damaged components rather than go on a wild goose chase adjusting settings away from those specified by the manufacturer.

If many thousands of Octavias are running OK with the manufacturer specs without severe rear tyre wear then why should this particular example be any different? Any set up is only as good as the operator and equipment of course - who's to say that the calibration of the alignment kit was not a bit out?

Incidentally, I am speaking from the perspective of some years experience of chassis development (I was a development engineer at MIRA for a good few years).

Good question, why should many thousand Octavias run without adverse wear?..... Well the problem is not as isolated as you think and i feel this complaint is the pinnacle of many more to come?

To explain: In a perfect world we all have idyllic coil and damper ratio, 2.2 children, always have a full fuel tank and drive 50/50 motorway-A road.

The chassis calibration assumes that.... the target data offers that, but in the real world the parameters "change".

No one in their right mind would assume the design team could predict future deterioration of the suspension and chassis so it's up to, i don't know "fast fit" to realize the compliant and deal with every example as "unique".

As i have said before and i say it again, it's for these reasons the manafatures Geometry calibration positions are at best "suggestions".

Incidentally, I am speaking from the perspective of some years experience of chassis development (I was a development engineer at MIRA for a good few years).

So you haven't actually had some 120kg boofhead, who has spent a weeks pay on tyres only to have them knackered in 10,000km, hovering over you while you try to explain that "It's all within specifications.":rofl: They don't care what the specification is, they just want it fixed.

For a car with relatively low mileage my suggestion would be to look for worn/defective/damaged components rather than go on a wild goose chase adjusting settings away from those specified by the manufacturer.

Hi,

Thanks for your input.

I am in no way questioning nor wanting to improve on the OEM settings. I would love to have correct OEM settings! The issue of the tyre wear arose after an alignment check had been carried out by a Skoda dealer. The first 30k miles exhibited no uneven wear on the rear tyres.

The alignment was checked by the same dealer and the camber found to be way out. Unfortunately I have no faith in their work from the initial settings and also the fact that their last alignment session has left the steering wheel off centre.

It may well be that a component is damaged but would that result in the same level of uneven wear on each tyre? Indeed if something is damaged, I would like a cometant mechanic to identify that rather than go through the motions of a procedure or job step.

I don't want a chassis set up to "Fast Road" settings, with an accuracy so precise that the Internet forums sill be agog, merely a car that I can feel confident in driving 20000 miles per year, many of those with kids in the back!

Steve

When the first Opel bodied Holden Commodores were introduced in Australia in 1978 the front camber was -1.5 degrees which was great at first but after a short while the European designed but Australian tuned front end couldn't handle the weight of the 3.3L cast iron straight 6 or the 5L cast iron V8 that was fitted. The front end had excessive vertical movement & the inside of the tyres would wear and the car would pull left. The fix was to knock the camber back to -1L/-0.75R and add more castor offset on the L. Suprise, suprise - the new model came out with factory specs similar to what we'd been using because somebody had got it wrong despite all their testing. It appears the rear end of the Skoda might be similar.

That's very interesting; was the Oz market 3.3l 6 significantly heaver than the "cam in head" 2.8l and 3.0l straight 6s that the vast majority of European Commodores and Senators had?

Also, did Holden not use a locally cast version of the the GM US Mouse motor for a V8?

That's very interesting; was the Oz market 3.3l 6 significantly heaver than the "cam in head" 2.8l and 3.0l straight 6s that the vast majority of European Commodores and Senators had?

Also, did Holden not use a locally cast version of the the GM US Mouse motor for a V8?

I've no idea of the weights etc & I've only ever seen 1 Opel up close - my wife has an Uncle near Munich. Our six was based on an engine that was first released in ~1964 as a 149 cubic inch and had minor changes since and grown to 202 cubic inch. 2 overhead valves per cylinder, usually a single barrel carby (up until the later models in ~ 1979), cast iron 6into1 manifold. These soldiered on in production up until the introduction of unleaded petrol in ~1987. It isn't that they were stupidly heavy but there was a lot forward of the axle.

We had our own home grown V8s in 4.2L & 5.0L capacity. They were somewhat lighter than small block Chevs despite their cast iron blocks. Again, these first appeared in 1969 and soldiered on until ~2000. The Holden & Ford engines both featured prominently in our Australian Touring car championship. IIRC they might have run them either at Spa or LeMans back in the '80s.

They were both a lot of engine (weight) for a vehicle that was initially under-engineered for Australian conditions (even urban roads).

Ah, if your GM 6 was a conventional cam in block OHV it was very different from the Opel cam in head unit (still technically OHV, but pushrods only about 3" long, so most of the advantages of an OHC unit in solid lifter form).

Also, I don't know about the Oz engines, but GM (US) Mouse motors ("small" blocks, typically 260 to 350CI) actually weigh less than most 3 to 4.5l 6s!

I don't disbelieve you; it's just that, unless Holden changed the suspension design or you were using heavier blocks, it seems strange that you had problems on seal when Europe didn't.

I don't disbelieve you; it's just that, unless Holden changed the suspension design or you were using heavier blocks, it seems strange that you had problems on seal when Europe didn't.

Crap Aussie roads, crap Aussie suspension components, crap quality assurance, inappropriate transfer of technology & design, small engineering budget.

Good(ish) cars once you got them sorted though.

Well a big thanks to Nigel Langs Garage in Bolton who have correctly set up the car. Thanks also to Tony from WIM who spoke to the Hunter alignment machine operator, Paul, helping him with the settings.

I've attached the alignment report.Alignment settings 13-11-08.pdf

Needless to say, the steering wheel is now straight and I am annoyed that the Skoda dealer passed the car as fit with such an error. I will be writing to the dealer manager to explain why I won't be using them again, copying the letter to our fleet manager and the lease company.

Steve

Looks like you have a result there, Steve. Well done and enjoy.

Well a big thanks to Nigel Langs Garage in Bolton who have correctly set up the car. Thanks also to Tony from WIM who spoke to the Hunter alignment machine operator, Paul, helping him with the settings.

Steve

I have a suspicion that the basic problem was the "rear thrust angle". That misalignment would mean that the rear tyres were being scrubbed along the road whenever you tried to drive in a straight line.

I have a suspicion that the basic problem was the "rear thrust angle". That misalignment would mean that the rear tyres were being scrubbed along the road whenever you tried to drive in a straight line.

Very much so... The thrust angle is the front wheels forward reference point, no matter how many times the front was adjusted the steering would never be straight with such a violated thrust.

Glad you got this sorted.

I hope the dealer pay up for this. I'd also copy your letter to SUK. It's not like it's an unknown issue....

I'll do that.

Once I have any response from the dealer, I'll post it on here.

Steve