Historical Information of Other Track Bike Racing Venues Add some pics/links to the Polo Grounds, the bike racing at the SJ Speedway??, the Oakland 6 day??The MashSF page, https://www.mashsf.com/uncategorized/historic-polo-fields-golden-gate-parkSacramento Velodromehttps://www.facebook.com/groups/YesterdaysVelodromes/posts/835545873665223/