I feel like I'm going over rumble strips

[Terry1]

I took my Focus on a 140 mlie ride last Saturday. No problems besides a little shake around 65 mph. I'm aware of balance and alignment, but this seems like a different problem. On my return home, as soon as I drove on to a smooth paved road the problems started. Exactly between 20-25 mph, I get the weirdest vibration. It's like I'm driving on grooved pavement or small rumble strips. If I go slightly faster it's gone. I've tried throwing it in neutral and it still does it. Same thing whether I'm speeding up or slowing down. Boom, right at 20-25 mph. Also, when I finally got through slow traffic and hit the highway at 65 mph , I get a very weird shimmy. I can look at the steering wheel and see it move. This does not sync up with the driveline rotation at all. It is not violent like a shake, more like a rhythm than anything else. I picked up speed, around 70-80 mph for about an hour and a half with no shimmy at all. I'm also hearing some kind of metallic sound in the front end on a low speed left turn. Can't really narrow it down. I had the car up on jackstands yesterday and couldn't find anything loose or making noise. I wouldn't start the car like that, I just spun the tires in neutral. I had both bearings, drivers side axle and drivers side balljoint replaced last year. I've been talking to the mechanic that did the work, and he insist it's the front tires. I have three sets that have been switched around though. I'm trying new tires with a balance tomorow, which I do need. But I'm certain that's not this particular problem. I read too many threads, so I've got too many ideas in my head now. I know this is long winded, but I wanted to go into detail as much as possible.

[Auto_Focus]

If your mechanic thinks that it's the front tires; why don't you have a tire shop put it on a balancer and see if the tire has a broken belt or other defects that you can't see with just a visual inspection.

[Lancer211]

Might be resonating.

[Terry1]

Tires ! I didn't have a chance to hit the highway yet, but the low speed issue is gone. I still have a little rotation noise up front. Thats always been there anyway. I'll take it out for a high speed ride today. I didn't want to take a chance last night with all the people out and about for the 4th of July celebrations. Including the police. I'll check the old tires thoroughly today to see what happened.