Front tyres jumping when putting full lock on C63 AMG

[Carsey1974]

Hi just bought C63 AMG coupe. Front wheels seem to jump on turning on full lock and semi full lock at slower speeds like reversing into bay or a tighter than normal turn. Any help appreciated. Tony

 

[CaptainChaos]

Try it today now the weather has warmed up.

 

[sgregory124]

Hi just bought C63 AMG coupe. Front wheels seem to jump on turning on full lock and semi full lock at slower speeds like reversing into bay or a tighter than normal turn. Any help appreciated. Tony

It's a 'feature', due to the geometry setup on these cars. Anything other than all-season (I think) or winter tyres will crab when you're on fall lock. So you'll need to get used to it unfortunately. Mine does it all the time when the temp outside is lower than about 5 degrees - doesn't bother me any more now I know the car isn't going to fall apart

 

[Carsey1974]

Try it today now the weather has warmed up.

Will do I had read it may be the cold, I was thinking Are the tyres too big?

 

[sgregory124]

Will do I had read it may be the cold, I was thinking Are the tyres too big?

Not the OEM wheel/tyre combo no. The geometry is setup in such a way (aggressively) that the suspension forces the tyres to crab - there have been lots of discussions on whether or not it can be corrected. Mercedes are not interested in sorting it though, according to lots of people who've tried them.

 

[Carsey1974]

Not the OEM wheel/tyre combo no. The geometry is setup in such a way (aggressively) that the suspension forces the tyres to crab - there have been lots of discussions on whether or not it can be corrected. Mercedes are not interested in sorting it though, according to lots of people who've tried them.

Thanks for the reply it doesn’t bother me as much as it does the Mrs now she’s like I don’t like it it’s not a family car

 

[Petrol Pete]

Thanks for the reply it doesn’t bother me as much as it does the Mrs now she’s like I don’t like it it’s not a family car .....

Don't let her drive it. The 'problem' will immediately go away

 

[Carsey1974]

Thanks for the reply it doesn’t bother me as much as it does the Mrs now she’s like I don’t like it it’s not a family car .....

Don't let her drive it. The 'problem' will immediately go away

Told her that, it didn’t go down too well as I had already traded her RR in to get this

 

[CaptainChaos]

As mentioned above it's the geometry. The OP will be able to see it if he parks on full lock. A good portion of the tread is not touching the road. It's not specific to the AMG cars either. My C350e suffered from it.

 

[Philv58]

My C 220d 17plt suffers the same, its worse when its damp, I have read that Continentals are the problem, so maybe a different make might work, I will give it a try next time round.

 

[Bobby Dazzler]

Although the geometry won’t be helping, the reality is that very wide, very low profile very high performance summer tyres are very very stiff, and in cold weather they become much much harder. As a tyre ages the rubber becomes even harder still, and the tread blocks wear away the amount of give/flex reduces.

Combined, these factors significantly reduce the amount of flex available in the tyre - both the sidewall and tread blocks -and as a result the lateral forces exerted upon the tyre when turning sharply exceed the lateral grip and flex available in the tyre, and so the tyre skips across the surface of the road leading to a vibration or judder.

Replacing the tyres with new summer tyres can sometimes improve the symptoms because the tread blocks are deeper and the rubber more subtle, however the optimal solution is to fit high performance winter tyres. Compared to summer tyres they stay much softer in cold conditions, tread blocks are much deeper, and the tread blocks are designed to generate heat.

Whilst you notice these symptoms when driving at very low speeds turning sharply, the same factors limit the tyres ability to perform when driving at speed too. It’s less noticeable until you push the car too hard in cold conditions, and then it becomes very very noticeable. Winter tyres are important on a high performance car which is used all year round.

 

[Carsey1974]

Although the geometry won’t be helping, the reality is that very wide, very low profile very high performance summer tyres are very very stiff, and in cold weather they become much much harder. As a tyre ages the rubber becomes even harder still, and the tread blocks wear away the amount of give/flex reduces.

Combined, these factors significantly reduce the amount of flex available in the tyre - both the sidewall and tread blocks -and as a result the lateral forces exerted upon the tyre when turning sharply exceed the lateral grip and flex available in the tyre, and so the tyre skips across the surface of the road leading to a vibration or judder.

Replacing the tyres with new summer tyres can sometimes improve the symptoms because the tread blocks are deeper and the rubber more subtle, however the optimal solution is to fit high performance winter tyres. Compared to summer tyres they stay much softer in cold conditions, tread blocks are much deeper, and the tread blocks are designed to generate heat.

Whilst you notice these symptoms when driving at very low speeds turning sharply, the same factors limit the tyres ability to perform when driving at speed too. It’s less noticeable until you push the car too hard in cold conditions, and then it becomes very very noticeable. Winter tyres are important on a high performance car which is used all year round.

Thanks for the in depth reply makes a lot of sense winter tyres it is and see how they go I will keep you updated. Thanks

 

[Bobby Dazzler]

Thanks for the in depth reply makes a lot of sense winter tyres it is and see how they go I will keep you updated. Thanks

You’ll be amazed by the difference they make - depending upon the age, compound, design and tread depth of your current tyres the difference could be anything between noticeable and transformational!

 

[Scooby_Doo]

Told her that, it didn’t go down too well as I had already traded her RR in to get this

That's a bit of a comedown - Rolls Royce to C63

 

[Carsey1974]

That's a bit of a comedown - Rolls Royce to C63

Range Rover

 

[Philv58]

Although the geometry won’t be helping, the reality is that very wide, very low profile very high performance summer tyres are very very stiff, and in cold weather they become much much harder. As a tyre ages the rubber becomes even harder still, and the tread blocks wear away the amount of give/flex reduces.

Combined, these factors significantly reduce the amount of flex available in the tyre - both the sidewall and tread blocks -and as a result the lateral forces exerted upon the tyre when turning sharply exceed the lateral grip and flex available in the tyre, and so the tyre skips across the surface of the road leading to a vibration or judder.

Replacing the tyres with new summer tyres can sometimes improve the symptoms because the tread blocks are deeper and the rubber more subtle, however the optimal solution is to fit high performance winter tyres. Compared to summer tyres they stay much softer in cold conditions, tread blocks are much deeper, and the tread blocks are designed to generate heat.

Whilst you notice these symptoms when driving at very low speeds turning sharply, the same factors limit the tyres ability to perform when driving at speed too. It’s less noticeable until you push the car too hard in cold conditions, and then it becomes very very noticeable. Winter tyres are important on a high performance car which is used all year round.

Thank you, thats made more sense of it now,

 

[Mactech]

Thank you, thats made more sense of it now,

Mr Dazzler is absolutely correct in what he says. But is actually a geometry problem which is common to all brands of car using modern low profile, wide rim based tyres.
All cars use the Akerman principle to run the inside wheel at tighter radius than the the outer wheel. For wheels with very little width and high profile tyres, it works just fine. Now we have wheels which are considerably wider and during a tight turn there is a need for the outside of the wheel to describe a larger radius than the inner. Unfortunately, they are both constrained on a very rigid (and wide!) alloy rim making the compliance of the tyre the defining factor as to whether the tyre 'skips' or distorts.