Unique to Mercedes?

[rf065]

Hi,

I noticed Mercedes front wheels lean at an angle when on full lock. I seem to remember an explanation years ago and something about King Pins.

Can anyone explain why Mercedes cars do this, what are the advantages and are there any disadvantages?

Russ

 

[Blobcat]

Tight turning circle is one of the advantages. Although the newer cars with large wheels/tyres have lost some of that advantage

 

[MIW615]

Hi,

I noticed Mercedes front wheels lean at an angle when on full lock. I seem to remember an explanation years ago and something about King Pins.

Can anyone explain why Mercedes cars do this, what are the advantages and are there any disadvantages?

Russ

The majority of cars do the same, it's called king pin inclination, the amount of the angle depends on the suspension / steering design. The main reason for this is to improve / assist in the self-centering of the steering

 

[rf065]

Thanks guys,

I would have to say that the angle on Mercedes cars seems to be far more pronounced than other makes.

Russ

 

[MIW615]

This shows the angle.............

 

[MIW615]

I would have to say that the angle on Mercedes cars seems to be far more pronounced than other makes.

Russ

As I said, it depends on the manufacturer's design and requirements

 

[kth286]

All

It is the high CASTOR angle built into the front geometry.

Taking my car as an example the castor angle is of the order of 10 degrees wheras normal cars of the time averaged half of this ie. 5 degrees.

Castor is the angle between the steering axis and a vertical line drawn through each roadwheel's centre and tyre contact patch, when view from the SIDE of the car.
Positive castor is when the steering axis is tilted so that it contacts the ground ahead of the vertical.

This makes for a very relaxed drive on long journeys as it contributes to a relaxed steering feel as there is very little need to keep correcting the steering with constant small inputs from the driver - the legendary Mercedes feel.

The negative factor is that as the road wheels turn one way and then the other way, the CAMBER changes (as mentioned by the first poster) and this physically alters the height of the car. Therefore, when driving through the twisties with a lot of steering, the change of CAMBER first one way and then the other way causes the car to actually raise and lower and is hard work on the steering and makes the car less manoeuvreable than cars with smaller CASTOR angles.

As Mercedes have made big play of driveability of their cars through bends with the latest models, I would guess that CASTOR angles have been reduced on newer models. Does anyone know????? With the reduction of the relaxed high speed straight line qualities of the older Mercs.

 

[wireman]

There are two angles, castor measured on the side which self centres the steering and camber measured on the front plane which affects road holding and comfort. The mercs small turn circle makes it such that it is very obvious that the resulting compound angle is very visible at full lock.

 

[gordofski]

Hi,

I noticed Mercedes front wheels lean at an angle when on full lock. I seem to remember an explanation years ago and something about King Pins.

Can anyone explain why Mercedes cars do this, what are the advantages and are there any disadvantages?

Russ

take a look at a london taxi cab doing a turning circle, no it isn't unique to Mercedes