Had it above 140 several times on flat ground...no issues.
I was in excess of 150 on the banking at Fontana...really felt nailed down as it was being pushed to the assphalt. D. Smith had just told me in the grid not to be a pu$$y. He was right...in that venue, 10 mph slower didn't feel as good.
This was with a toploader...but lots of revs left thanks to Boghosian.