Mine had done 42k. It went very quickly. I thought i was feeling some grinding through the footpegs on my 30 mile journey into work. On the return journey I definetly felt it. Went to work on the bike the next day (yesterday) and the grinding went from being noticable, to worrying, on that 60 mile trip. Strangely it was hardly detectable at 70mph but at low speed and on the over run it was dire!
It started to feel bad enough that I would have parked it up and left it, if say Neil hadn't been able to do it for a week. Not sure if it would have got steadily worse or anything, but I wouldn't have been happy riding it like that.
Cheers
Dave