I purchased a set of Conti Contact Extreme 215/50/17 (stock size) and had them installed yesterday. I watched them do it and saw the balancing at 0 on all four tires. Drove home (app. 2 miles) and the car felt like a dream. Drove it a little later on that day and they car was jittery as hell and the steering wheel was shaking (got worse at higher speeds). I returned to the shop this morning and they placed the tires back on the machine and one tire was .75 another was .50 and a third was .25 They re-balanced all four tires and I drove out again feeling wonderful. Any ideas what could have caused this??????????

PS. It's still sitting outside my house. I hope that I dont' have the same problem as yesterday.

 

it might be your rims being bent a little. usually this will happen when you go at speeds around 60 - 80 mph. try it again at that speed and see if it happens.

 

you said the initial balancing was perfect...with or without weights? if with weights, did any fall off?

 

with weights

 

How far is your house to the tire store? When my contis were new, I noticed some flat spots every morning after the car has been sitting over night. It usually rounds off after a mile or so. Now, after putting over 1000 miles on them, I don't notice the flat spots anymore in the morning. If your house is far away from the tire store then I have no idea.