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[wheels-inmotion]

Hello tony.  Great info on your site.  Many thanks for putting it all up.

When i replaced my front wishbones i stupidly neglected to check the alignment afterwards and in a few hundred miles had destroyed the inner edge of two good front tyes

It went quick smart to STS Wheel Alignment Centre in Bedford.  They use a Hunter system and if i recall their prices were something like 50 quid for a full geometry check including basic adjustment (i.e. toe) and about 20 quid more for more adjustments (i.e. camber).

I was able to watch the guy doing his thing.  Was quite interesting.  All the angles came up on the screen (including the 'extras' mentioned above) compared with VXs spec.  My front toe was off the scale out after the wishbone change and the cause my tyre wear problem.  I noticed with surprise that my track control adjusters both cracked loose easily enough (and the guy pointed out one of my TCAs was slightly bent!).

Camber was interesting too.  Both front wheels were in VX spec but were literally either side of the scale and so there was over a degree between them.  Now if I was a cynical git, I'd say that he didn't need to adjust camber as it was in spec, and only did it for the extra cash.  But i'm more inclined to give him the benefit of the doubt and say he noticed the big variation in camber between each wheel (albeit within spec) and deemed it important to adjust them properly to be near enough equal.

At the end of the day he cured the horrible tyre wear and the pull to one side and my meggy now drives great!!  So that's a recommendation for STS Wheel Alignment Centre in Bedford.  Got a nice before/after/VXspec printout too.  Now I even know my car's thrust angle - woo hooo:)

Liam

The Dynamic range has no relevance to the operator setting the geometry. Dynamics are for mechanical engineers..... Have a read of this it may help you understand the 'Static and Dynamic' conundrum.
www.wheels-inmotion.co.uk/forum/index.php?showtopic=213

[RonaldMcBurger]

I think all this wheel alignment stuff is nonsense. I changed the wishbones on my Omega in February and did 4000 miles after that without any problems at all.

I found that the car didn't pull that badly and could easily be corrected by bouncing off the nearside kerb every 200 or 300 yards. Also the tyres were fine and I only had to replace them 7 times in that whole 4000 miles, so I don't get all this wasting money on alignment.

And another thing, The car was much easier to park after I did a DIY tracking myself. Basically undo the track rods, stand about 30 yards in front of the car and look which wheel looks a bit out. Adjust and repeat until the look about the same (within 4 or 5 inches anyway) and Bob's your auntie. parking into right hand bays was much easier than left ones, but that was because the crabbing was severe that side, but that's how I like it.

Also, by doing the job yourself using mole grips I found a surprising bonus. It makes people more friendly. I had no end of people waving at me and shouting great comments like 'your tyres are smoking'. Well, what more can I say? With comments like that, who needs Tony at Watford?

[Andy B]

Thanks for the info, paul_wighton in Oldham has just been emailed, thanks for the Trusted links.

Have you been to Oldham yet? If so how did you get on? I'm still not sure about the set up on my car and the further I go the more I worry about bu99ering up my new tyres.   It was all supposedly 4 wheel set but it still has a tendancy to pull slightly.

[wheels-inmotion]

Thanks for the info, paul_wighton in Oldham has just been emailed, thanks for the Trusted links.

Have you been to Oldham yet? If so how did you get on? I'm still not sure about the set up on my car and the further I go the more I worry about bu99ering up my new tyres.   It was all supposedly 4 wheel set but it still has a tendancy to pull slightly.

Was you given a printout? if yes can you display some figures? if no then the alignment must have been Laser, so linear and worthless for the Omega.

[Andy B]

.....

Was you given a printout? if yes can you display some figures? if no then the alignment must have been Laser, so linear and worthless for the Omega.

A four wheel linear ref'd from rears.   Looks like I should pay a visit to Oldham then.
Just to confirm -I should be asking fo a "Full Geometry/primary and Secondary" check!?

[wheels-inmotion]

.....

Was you given a printout? if yes can you display some figures? if no then the alignment must have been Laser, so linear and worthless for the Omega.

A four wheel linear ref'd from rears.   Looks like I should pay a visit to Oldham then.
Just to confirm -I should be asking fo a "Full Geometry/primary and Secondary" check!?

Very good question! All Geometries measured in the complete form will include the secondary angles, but most only measure the primary angles..... The reason is the secondary angles need a little more work to measure and a heap loads more explaining if found to be wrong.. so most avoid measuring the secondary angles although you are entitled to them on any Geometry! An indication of how complete the Geometry is would be the inclusion of the Castor angle, if this is on the report then that's a full Geometry.

[Marks DTM Calib]

Tony, is there a set of recommended settings for the Omega or are the 'factory' advised ones ok?

[TheBoy]

Mark, I know Tony adjusts it to what he finds on the car as it goes it, so I believe that tends to take into account personal driving conditions/style.

I believe, for example, my camber is right at the very edge of Vx spec to suit my car.

Also, I believe the Vx specs are 'static' and do not take into account the 'dynamic' settings.  Whilst I don't understand all the theory (all on WIM website), all I can say is the result on my MV6 was 'transformation' - both on tyre life (was eating fronts, despite many '4 wheel alignments' previosuly) and handling.

I'm sure Tony will put me right on any inaccuracies in my post...

[Andy B]

......
Very good question! All Geometries measured in the complete form will include the secondary angles, but most only measure the primary angles..... The reason is the secondary angles need a little more work to measure and a heap loads more explaining if found to be wrong.. so most avoid measuring the secondary angles although you are entitled to them on any Geometry! An indication of how complete the Geometry is would be the inclusion of the Castor angle, if this is on the report then that's a full Geometry.

Thanks for that.

[Liam]

The Dynamic range has no relevance to the operator setting the geometry. Dynamics are for mechanical engineers..... Have a read of this it may help you understand the 'Static and Dynamic' conundrum.
www.wheels-inmotion.co.uk/forum/index.php?showtopic=213

Hmmmmm, had a read of that.  Agree with most of what you say regarding the need to go for good accuracy setting up geometry, but regarding your interpretation of the manufactures specifications, surely you are mistaken!

You say the manufacturer's 'specified range' is in fact the full dynamic range over the whole suspension travel.  I.e. the complete range of positions the suspension can take whilst moving, from full droop to full bump, in full roll and at full lock.  Well it surely isnt, and actually can't be.  The specified range is just that - the manufacturers specified static settings with an allowed tolerance either side.  For example (using the figures on the printout in your linked thread) the static camber (at laden ride height) can be set anywhere from -0.50 to +0.40 (and ideally bang in the middle) and that vehicle will operate within the manufacterers intended parameters.  If the specified range shown was in fact the full dynamic range, the 'specified range' on the machine would be well over 5 degrees on camber.  Similarly with toe - the machines will give a specified range of only about 0.10 degrees to set within, but due to toe-out-on-turns (ackerman) the dynamic range of toe is around 1.5 degrees.  Caster will have 0 dynamic range (well actually it will change a tiny amount with mcpherson strut suspension) but here the manufacturers specified range will be a good degree or so allowing for manufacturing tolerance and bush wear.

You quite rightly point out that the full dynamic range would be irrelevant to setting up static geometry - so I ask why the manufacterers would bother supplying that information and why the machines would display it?  The answer is that the specified range is not the full dynamic range, but simply the static setting with a tolerance.  Also, if the specified range was the full suspension/steering travel, it wouldn't necessarily be correct to aim for the middle of this range for the static settings (certainly not for front toe!), yet that's what you aim for when setting up geometry.

However it's all merely academic I suppose and doesn't actually effect the way you do your job (very well by all accounts).  You get cars set up bang in the middle of the specified range and even side-to-side rather than being happy as long as the settings are somewhere within the manufacturers tolerance, which is admirable pride in your work.  But the specified range is just an allowed tolerance of static settings, and the machines dont pointlessly display the whole range of the vehicles suspension/steering travel.  This might explain why you are most probably fobbed off when you "argue this fact directly with the manufacterers".

Liam

[wheels-inmotion]

Reply:- Liam

Indeed there is some confusion within the 'Specified-static-setting' range. You example the 'specified range' -0.50 to +0.40 as a target position. Also displayed there is a 'cross position' and a limit to the disparity over the axle, a combination of the two would be dire to the owner (agreed) One area withing Geometry i respect is the 'tendency' toe/camber and so on... This is highlighted by the free 'fine-tunes' done by wim... the principle is born on the fact 'NO' Geometry is final! The initial set-up will deliver an image of the cars positions.... the fine-tune can detected any need to deviate from the initial positions. So in truth the real Geometry is the second one, and for that reason it's free!

I am definitely not the law within Geometry or chassis dynamics, we all have much to learn in this field since it involves so many examples and parameters ever being expanded by new developments. What i do welcome is the chance to explore knowledge within others, this is something any car club would welcome as beneficial.... Non hostile communication is healthy do you agree?

[Markjay]

Mark, I know Tony adjusts it to what he finds on the car as it goes it, so I believe that tends to take into account personal driving conditions/style.

I believe, for example, my camber is right at the very edge of Vx spec to suit my car.

Also, I believe the Vx specs are 'static' and do not take into account the 'dynamic' settings.  Whilst I don't understand all the theory (all on WIM website), all I can say is the result on my MV6 was 'transformation' - both on tyre life (was eating fronts, despite many '4 wheel alignments' previosuly) and handling.

I'm sure Tony will put me right on any inaccuracies in my post...

Same here, my 2.6 CDX is a plessure to drive since Tony had a go at it - sharp and precise steering, and the sort of handling that makes you smile quietly when you negotiate a bend. I had the car from when it was 6 months old, and it was never like that even when new. In fact I am thinking of taking the car to him every 3-4k for checking/correcting just to make sure it stays as it is.

As for the settings, yes Tony does not like the factory defaults, he tends to use setting at the edge of specified measures, but this seem to work fine as noted above...

(and last, you can actually talk to him and he will take the time to listen to you and also to explain what he is doing... I like this about a garage, which is unlike Vx where the most qualified person you get to speak to is the guy at the parts counter, because the service receptionist no bugger-all about anything!)

[wheels-inmotion]

I honestly welcome debate regarding this topic since no one person could possibly retain all the dynamics in his head. My opinion for the Geometry positions on the Omega means nothing unless tried and tested.

Scary as it reads the manufacturers do get it wrong sometimes... Two years ago wim was approached by LOC (Lexus owners Club) desperately trying to solve front tyre wear issues for the members..... After some  dynamic/ static calculations the reason for the problem was apparent, a few cars from the club were invited to hold these new positions.... the rest is history.. In 2005 wim published the new positions (free).

The point is Geometry is not a drive by set-up, every car/ owner is unique, tolerances and dynamics in the real World are 'pants' The real deal is on the floor and the understanding of the man holding the spanner..... Oh and then the maths?