My 2008 1800 has 33000 miles on it. I had new brakes put on last year and had the 32000 miles service done a few months ago. Yesterday on my way home, I started hearing a thunka-thunka noise that sounded like it was coming from the front of the bike. I just spun the tire without the bike running, but didn't hear anything. I noticed when I was nursing the bike home at a slow speed that if I slightly engaged the front brakes the noise seemed to stop or diminish greatly. Any ideas? Oh yeah, I put on the centramatic wheel balancers when I changed the tires last year.