for a lot of diversity look at San jose Bike party. it is an event, but it not viewed postively by many people in the biking community.
my observation is that there are three broad visible groups of cyclists in the san jose area. this is not scientific and the sizings are not
Relatively affluent cylists, who commute, ride recreationally, kids ride errands. The commutters seem to be predominantly white males, people riding recreationaly are very diverse (go to los gatos creek trail on a weekend). Bike clubs seem to reflect this group
People working low paying jobs, often in service and food areas. Look behind restraunts and car washes and you will see a lot bikes. Many are hispanic
Homeless people. Broad diversity as the causes of homelessness are diverses.
in this area both of the later two groups are well served by
www.goodkarmabikes.org The make up of good karma it self is diverse, and many clients go on to volunteer at good karma.
don't know if it helps