Kris Schamp
2008-06-06
Two things that you have to take in consideration - at least here in the Portland area:
1) we have a very busy and highly popular scene of midweek races, and
2) a lot of MTB racers are also racing road and/or track.
Comes May - and especially June - a lot of folks shift their race focus to PIR Road, Mt Tabor, MTB Short Track and/or Alpenrose. Often, the summer weekends then become the time to rest, hang out with the family, or ride the trails with friends.
Another issue that has been brought up here before is that some of the MTB venues are not available in summer, either because of alternate (read: more popular) uses during that time (that's the case at Horning's for instance) or because of fire season policies in drier areas.