Not a club per say, but there are a number of us in the Sacramento area. Sadly, with the weather just turning the last couple days I think we've pretty much run out of 'season' for the rest of the year, unless you want to come ride the flat (aka boring) lands.
'06 Speed Triple
'96 Adventurer Cafe Racer
and a bunch of other stuff
If everything seems under control, you're just not going fast enough - Mario Andretti