Jonathon wins with his guess "It's the Pasadena Motorcycle Club, founded in 1907."
In the photo above, members of the Pasadena Motorcycle Club pose for posterity before heading out for a 163-mile round-trip rally to Ventura on April 28, 1911.
They're in front of the Victor Marsh Building at the northeast corner of Raymond Avenue and Green Street. The building still stands today, although it has been significantly altered. The first floor at that corner is now occupied by redwhite+bluezz.
Here's a photo of Carl Marsh on the way to Pasadena for the rally, stopping to rest with his Indian among the orange groves.
Founded in 1907 as a sporting club that held Hare and Hound races in the local orange groves, the Pasadena Motorcycle Club celebrated its 100th anniversary in 2007.
Here are club members in 1925:
They even have a Facebook page!
