there are a few possible thing which could cause vibrations,

1. when breaking hard, your discs could take up some heat and get warped, great article could be found here:

http://www.mossmotors.com/SiteGraphics/Pages/brake_discs.html

2. bad geometry could cause vibrations + uneven tyre wear (flat spots maybe?), see related article:

http://ebcbrakes.com/articles/steering-wheel-vibration/

3. check wheel balancing, article here: https ://www.bigotires.com/librarydetail/Tire-Balancing---Why-Does-it-Matter

I would recommend to check these first, there are couple more issues but these are the most common, which could possibly fix your problem.

Boris

There are a few possible things which could cause vibrations:

1. When breaking hard, your discs could take up some heat and get warped, great article could be found here.
2. Bad geometry could cause vibrations + uneven tyre wear (flat spots maybe?), see related article.
3. Check wheel balancing, article here.

I would recommend to check these first, there are couple more issues but these are the most common, which could possibly fix your problem.

Boris