Neons & Neutrals Nylon/Spandex Walking Bike Shorts. SIZE: OS REGULAR-ONE SIZE FITS MOST. NYLON STRETCH BIKE SHORTS. 92% NYLON, 8% SPANDEX. STRETCH SHORTS. XL 39-41 31-32 41-42. L 36-38 29-30 39-40. M 34-36 27-28 37-38.