Personalized San Luis Obispo California Biking Cyclist T-Shirt. Fun San Luis Obispo California bicycle design for someone who loves cycling on weekends or commuting to work on their bike Wardrobe essential for looking good, 24/7. 5.0 oz., pre-shrunk 100% cotton. Seamless 1x1 rib collar. Shoulder-to-shoulder taping. Double-needle stitched sleeves, bottom hem and front neck. Note: greys are a cotton/polyester blend.