General question -

Before new tires last week, silky smooth, zero shimmy.

After new tires last week, very noticible shimmy between 50-60 mph.

Can I be certain that it is the tires/balancing, or could the new tires have "enhanced" a shimmy with a different root cause?

I'm going to take it back to the tire store, but I know I'm going to hear, "It's the suspension, all BMW's are know for it."