How do tyre / wheel size effect handling

[mawallace]

Could someone tell me how the tyre / wheel size effect handling.

As an example, on the VW Golf you have a choice of 15 inch, 16 inch or 17 inch depending on the model you go for,

The standard tyres come with 225 / 45 R17 94 W .

How would choosing a smaller / larger tyre effect handling such as corning. and what about the tyre size, going for a different profile.

[PositronicRay]

Handling will be better on a smaller wheel/tyre combo, you may get better grip with a larger tyre.

[Kawasicki]

Smaller wheel, means taller sidewall..leads to less vertical stiffness, so probably more comfort, also the effective centre of the contact patch is further back, so you get more feedback due to changing steering wheel torque as the tyre loads up. Downside of taller, narrower tyres are less lateral grip, and longer time required to react to inputs. So wider, lower profile tyres on bigger wheels are potentially better if you need the car to follow driver inputs more faithfully, but they are sharper over impacts and probably more prone to impact damage.

[stevieturbo]

Depends what you're using it for, driving style, and what your perception of "handling" means...although of more importance would be tyre brand/quality with respect to what you're using it for.

[GreenV8S]

Tyre width makes the biggest difference, because it changes the shape of the contact patch. Changing the sidewall height while keeping the diameter and width the same will change the ride quality (and looks) more than the handling.

[stevesingo]

Kawasicki said:

Smaller wheel, means taller sidewall..leads to less vertical stiffness, so probably more comfort, also the effective centre of the contact patch is further back, so you get more feedback due to changing steering wheel torque as the tyre loads up. Downside of taller, narrower tyres are less lateral grip, and longer time required to react to inputs. So wider, lower profile tyres on bigger wheels are potentially better if you need the car to follow driver inputs more faithfully, but they are sharper over impacts and probably more prone to impact damage.

Can you please explain why this is? I'm intrigued to know.

[GreenV8S]

stevesingo said:

Can you please explain why this is? I'm intrigued to know.

A narrower tyre causes that effect due to the longer contact patch. There is more variation in lateral deflection from the front to the back of the contact patch, which increases the self-aligning torque of the wheel.

The mechanism that reduces that on wider tyres relies on the tread being able to deflect sideways ahead of the contact patch so I suppose it could be affected by sidewall height too.

[Mignon]

mawallace said:

Could someone tell me how the tyre / wheel size effect handling.

Not enough for you to be able to tell much difference one way or the other.

[james_gt3rs]

https://www.youtube.com/watch?v=mPyg3ilw3KU