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[feeutfo]

please read my tramlining thread..

I have. It's generalisations, and makes some assumptions to give not necessarily correct impressions. And wrong in places.

Tramlining of a tyre is 100% down to tyre rigidity.  Obviously suspension has an impact if you vary the chassis (and why tyre reviews are a waste of time, unless its on the same/similar chassis), but for different tyres on the same chassis, this is not relevent.

Mr Admin.. Today , I have read many pages about the subject.. And have notes from serious tyre sites, discussion groups where people agree on and some other helpful sites.. And later I summarize my notes and give some brief.. And it was not surprising to see their views were highly parallel..
 
By the way , most of the heated debates on tramlining were on BMW sites    
 
And I must add, your conclusion is highly personal and not reflecting the physic rules where general consensus is focused on..
 
 
 
 
 

Once again cem, no body is questioning your googling.

These are oddities that don't fit the normal rules. Hence the issues we've had, and the need for hands on approach.


The Chav wheel sizes you mention are indeed more likely to tramline. Fully accepted. Has been for years.

But look more closely within that statement, and my sc3 issue defies the accepted explanation.

Because the wider tyre of the two did not tramline AT ALL. EVEN WHEN WORN OUT.

there is no oddity in science Chris.. if there is an oddity , either your theory suffers from a bad equation with lacking/wrong parameters or it fails in general (=utter boll*x )
 
I have no doubt your issues are somewhere in those parameters which are defined (anyway they dont leave any parameter behind )
 
I ordered them from highest to lowest importance..
 
Unfotunately, I havent seen anywhere any measurement device for the degree of tramlining (which must measure force).. so we are talking about unmeasurable sense??? units.. may be there is tramlining , its compansated and you dont feel who knows..
 
 

its very very measurable
1 Number of corrections at the steering wheel required over a set distance at a set speed.
2 highest speed the driver ( the same driver ) feels safe to travel at on the same poor stretch of road.

Note, I also seem to remember you have over size wheels, no?

[feeutfo]

I have a section of road I test member cars over locally.

groomers sc5, 30 odd corrections. On his well sorted mv6 chassis btw. The same chassis that doesn't tram line with TT fitted.

Smd's odd ball set of tyres after fitting new wishbones and poly donuts. 10 tp 15 corrections and his car needed set up.

My sc3 mo. zero corrections, same stretch of road. My sc3 ao1 10-15 corrections. Same chassis, set up, wheels, driver.

Cem please explain?

[feeutfo]

Ps. Taxi Als Runway enduro stock 17 size, poly front and back. Same stretch 5 or 6 corrections.

Good for the money. Btw.

[cem_devecioglu]

cem, I accept there is a language barrier as English is not your first language (1.but you've really got to grips with it ), but you are completely missing the point.

Do they describe why wider tyres cause more tramlining? No. Its purely down to the tyres construction. Yes, the rigidity of a tyre will vary with width/profile if the construction and materials are identical. 2.But that doesn't simply mean that a wider tyre must tramline more.

4.Additionally, it doesn't explain why 4 matched SC5 tyres, 235/40/18 are so much more unstable in both a straight line, and under braking than 4 different branded, mixed summer/winter 235/40/18 tyres. On the same chassis. Remember, these are the same SC5s that Golf and Mondeo owners piss their pants over. I've done the £700 experiment, and can categorically say, they are most definately not suitable for our Omegas, whatever irrelevent reviewers say.

3.It doesn't explain why the current 235/45/17 tyres on my MV6 provide the most tramline-resistant ride of every single Omega I have ever driven, and I've driven an awful lot of them. Yet has the widest, lowest profile of the standard Omega sizes.

Beware, there is an awful lot of bullshit out on the Internet. I know, I posted some of it .  I know you work in IT, so you are aware that 99% of IT journalists are full of shit. I have no reason so believe that automotive journalists have a better ratio.

1.yes and thanks
 
2. question a: if there is no friction between the tyre and surface , will there be tramlining or not ?
   question b: is the surface of area of contact patch effects the sidewall pressure or not ?
   question c : is the surface area of contact patch changes surface heat (so rubber properties change) resulting with friction force change ?
 
3. You dont feel any tramlining doesnt mean there is not (see my post to Chris)..  A tramlining tyre doesnt mean its a bad tyre.. A tramlining car doesnt mean its a bad car..
 
4. You dont have any mesurement device in your hand to see the values of parameters and you dont have any F1 team mechanics backing you as far as I know.. How  can you solve an equation with n parameters with n unknowns

[feeutfo]

And not one single solution offered cem.

[cem_devecioglu]

please read my tramlining thread..

I have. It's generalisations, and makes some assumptions to give not necessarily correct impressions. And wrong in places.

Tramlining of a tyre is 100% down to tyre rigidity.  Obviously suspension has an impact if you vary the chassis (and why tyre reviews are a waste of time, unless its on the same/similar chassis), but for different tyres on the same chassis, this is not relevent.

Mr Admin.. Today , I have read many pages about the subject.. And have notes from serious tyre sites, discussion groups where people agree on and some other helpful sites.. And later I summarize my notes and give some brief.. And it was not surprising to see their views were highly parallel..
 
By the way , most of the heated debates on tramlining were on BMW sites    
 
And I must add, your conclusion is highly personal and not reflecting the physic rules where general consensus is focused on..
 
 
 
 
 

Once again cem, no body is questioning your googling.

These are oddities that don't fit the normal rules. Hence the issues we've had, and the need for hands on approach.


The Chav wheel sizes you mention are indeed more likely to tramline. Fully accepted. Has been for years.

But look more closely within that statement, and my sc3 issue defies the accepted explanation.

Because the wider tyre of the two did not tramline AT ALL. EVEN WHEN WORN OUT.

there is no oddity in science Chris.. if there is an oddity , either your theory suffers from a bad equation with lacking/wrong parameters or it fails in general (=utter boll*x )
 
I have no doubt your issues are somewhere in those parameters which are defined (anyway they dont leave any parameter behind )
 
I ordered them from highest to lowest importance..
 
Unfotunately, I havent seen anywhere any measurement device for the degree of tramlining (which must measure force).. so we are talking about unmeasurable sense??? units.. may be there is tramlining , its compansated and you dont feel who knows..
 
 

its very very measurable
1 Number of corrections at the steering wheel required over a set distance at a set speed.
2 highest speed the driver ( the same driver ) feels safe to travel at on the same poor stretch of road.

Note, I also seem to remember you have over size wheels, no?

1..Eh.. not bad.. finally some measurable things
 
2.back to square one
 
if you call 225/45 17 as oversize , yes.. but smaller than the size latest omegas use factory fitted..

[D]

Ah, a tyre thread. Should I say something???........... 

I might just add that the tyre test suggested may not really add true meaning. I say that purely because handling/tyres/steering feel is so subjective. In a way it is a trained/learned sensation/emotion. What feels right to one person, will not be appreciated the same way by someone else. Most of the population here belong to a normal group of drivers with varying driving styles, requirements and training. On the other hand if you were to say take a group of F1 drivers, then you might get some concordance in results. Yet you will get diversity even in those opinions. Then throw in suspension setup, predominantly 10+ year old cars which throws in another confounding factor. Lastly each persons estimation of what sort of driver they are. There is lots of research out there to suggest that self evaluation often produces a skewed picture, particularly with something as manly/egoistic/testosterone driven as driving.

I see cem's view point of just measuring physics; a very much a scientific way of doing things. But then driving is such an emotive subject, that perception just cannot be ruled out of the equation. I suspect this argument could go on for ever.

Back to the OP, I have driven on a full set of RT's up to Scotland and back. But this was on a BMW E39. Cannot for the life of me remember the wheel size, but they felt very planted on the cold and wet roads. But then I wasnt really testing them, just happened to be those tyres and my usual style of driving.

[TheBoy]

3. You dont feel any tramlining doesnt mean there is not (see my post to Chris)..  A tramlining tyre doesnt mean its a bad tyre.. A tramlining car doesnt mean its a bad car..

No, but if on the same car, one tyre tramlines and another doesn't, which tyre is best from a non-tramlining perspective?

And, if that same test using the same tyres is 100% repeatable on a 2nd car?

Surely, that shows its a bad tyre choice (for that car)?


The fact that the SC5 suffers less grip as well is just salt in the wound

[cem_devecioglu]

And not one single solution offered cem.

Chris, to solve a problem, you need lab(track wet & dry) , curves, gps, g measuring devices, different tyres and some electronic devices..
 
if you can have them solution is easy.. at least for a specific car and driver..

[TheBoy]

What feels right to one person, will not be appreciated the same way by someone else. Most of the population here belong to a normal group of drivers with varying driving styles, requirements and training. On the other hand if you were to say take a group of F1 drivers, then you might get some concordance in results. Yet you will get diversity even in those opinions.

But find a really suited one, I bet everyone will notice .  I reckon that Sport Maxx TT is as close as you can get to the perfect tyre for the Omega (ignoring wear)

Back to the OP, I have driven on a full set of RT's up to Scotland and back. But this was on a BMW E39. Cannot for the life of me remember the wheel size, but they felt very planted on the cold and wet roads. But then I wasnt really testing them, just happened to be those tyres and my usual style of driving.

Just what I was after, D, as per original post, thanks.

[feeutfo]

And not one single solution offered cem.

Chris, to solve a problem, you need lab(track wet & dry) , curves, gps, g measuring devices, different tyres and some electronic devices..
 
if you can have them solution is easy.. at least for a specific car and driver..

You just said there is no test for tramlining, yet here you are telling us to get lots of equipment. (Non of which the driver uses when driving)

And D, you've not read the full thread. All your points I covered earlier, on groups.

[feeutfo]

Although best feed back on rt yet.

[feeutfo]

For D.

Nope,don't need any equipment. Except to measure breaking, cones? wet and dry perhaps, but just what weather is on the day will do. Hopefully it will be consistent.

I'll wager, if we group drivers honestly, say 3 groups for arguments sake. Each group will come to the same conclusion, given the chance to drive the same car on each set.


We'll need 3 models of omega in sound mechanical order re suspension and steering and set up.
Mv6
Cdx or CD or Gls etc
Elite

Measure;
ride feel(comfort)
No of corrections at the steering wheel(tramlining)
Braking. (Difficult to get both wet and dry tbh. Wet might mean more)
Lateral load (speed on a constant curve, eg roundabout)
Noise (we have ears)

Easy!            

Although I'd accept completely the points on personal preference. As said earlier, if nothing else drivers can pick something out for themselves.

[TheBoy]

Although best feed back on rt yet.

Though still not an Omega....   ...but not a massively different car...

[cem_devecioglu]

3. You dont feel any tramlining doesnt mean there is not (see my post to Chris)..  A tramlining tyre doesnt mean its a bad tyre.. A tramlining car doesnt mean its a bad car..

No, but if on the same car, one tyre tramlines and another doesn't, which tyre is best from a non-tramlining perspective?

And, if that same test using the same tyres is 100% repeatable on a 2nd car?

Surely, that shows its a bad tyre choice (for that car)?


The fact that the SC5 suffers less grip as well is just salt in the wound

when evaluating a tyre, none of the tests include tramlining   
 
ok.. seriously, did you compare their brake distances in wet and dry..  curve abilities.. and whats the percentage of roads in total that cause tramlining ?
 
I'm afraid tramlining is not the single parameter to evaulate a tyre..
 
you dont answer my questions