That's been my top speed so far.

I've borrowed a pair of Madfiber wheels a few times. One reviewer complained about the wheel wobbling at 35 mph. I asked LBS about this, and they said it's a problem with that reviewer, not the wheels, and that a different rider won't experience it. I thought they just wanted to sell me the wheels, so I took them out again, and hit 35 mph going down a few hills. No hint of a death wobble ... I think that gives a lot of support to the harmonic theory.