[TeSmSp]

Today I did some high speed runs, between 85-90 MPH, sixth gear, and noticed more than usual engine vibration in that speed range. My bike has ~ 25k miles and I was wondering if it could be front tires, shocks, etc. The tires are Michelin PR2, from mid 2009 and seem to be still in good shape. However, there is some cupping in the front; the rear looks very good. Still running the original shocks.

 

[beech]

PR2's wear oddly quite often (trapezoidal) . I would re check the balance. If they are starting to cup, you might think about replacing if the rear is near worn too. Try the PR3's or Metzler z 6 or 8 interacts. Anyway I suspect tires,and seems you do too. Check your tire manufacture date. More than 4 years old, things are past due.

 

[TeSmSp]

Beech:
The rear date code is 2009, week 21. Front is 2009, week 37. About a year left in their life.