I have been riding the same road bike, a Fuji Espree, for a few years and am very used to it: I used to be able to ride it without hands on the handle bar very easily, take 90º turns in city streets because it is well balanced and responds in a predictable way.
I recently changed the old Strada-K Forte tires to new Continental Ride Tour Extra which have a more square profile, deeper grooves.
Since then the balance of the bike has felt off: As soon as I remove my hands from the handle bar, the bike starts steering to the right and even with my hands on it, turning feels harder. I'd like to find new tires that won't have that same effect but am not sure what feature is causing this? My intuition is that the more square profile is causing, do you think that is the case?