Originally Posted by
dminor
^^ Ahhh . . . most of the speeds in typical DH race sections are in the range of a normal 32T middle ring. But out West on big ski-slope mountains, there are parts where you'll spin out too early with gearing like that. I run a 38T chainring; although 36 is popular too. Fastest I've ever gone is a particular plummet off the edge of a ski run at Sun Peaks, B.C. that i hear got us to 40-45 MPH; but that is not typical.
It'll depend on the section of the course - the pinned speed over a sketchy rock garden with sharp turns will be much less than the pinned speed on a wide, sweeping doubletrack trail.