Ford Focus shaking up and down at speeds 30km/h-50km/h (I'm canadian lol)
Right so I just got my brakes done and all is well now in that regard. At the same time, I installed my winter steel rims and tyres. Driving down the highway I noticed that when I was at speeds 30-50km/h (rush hour) on the relatively smooth tarmac of the highway, I felt the car shake up and down. Not too violent but enough for me to notice. Then when I speed up to highway speeds it dies down but that maybe because I'm going much faster that the frequency of the vibration is too fast it's not noticeable anymore. I'm bringing it back in to the shop tomorrow to get it checked out but just out of curiosity what could cause this?
I personally am pointing at the new steel rims that I just installed but any other opinion? Everything is torqued to specification by the way