Yes you will shake your teeth out. The tyres will be very low profile so ride quality will suffer and you will be much more likely to damage both your tyres and rims.
It is fine on a track but on real roads not maintained well the bumps and potholes will be terrible. You will also have much ore risk of damaging your rims. I have seen rims destroyed in less than a week doing this and the warranty does not cover impact damage.
As long as you do not put Run Flat Tyres on the ride quality should not suffer much. If you run with the Run Flats then it is a terrible ride and you will soon regret the swap.
Wheels have nothing to do with ride quality. Silly low profile tires with high air pressure does!
Hi of course it will be a hard ride less air cushion between you and the road. that is why it will also give you inaccurate speedo readings.
tires are part of suspension/ride quality. less tire=harder ride
you'll have slightly firmer ride, feel more bumps.
The car is a E90 BMW.
