Machine wash delicate cold hang to dry here. What I've found is with my cycling clothes over the years is that with long term storage the elastic bands usually dry rots and crumbles long before the fabric itself is shot. Takes about 5-10 years for this to happen. The other thing that happens is that white fabrics can lose their luster. Chamois can lose padding too after both lots of miles and breakdown of foam padding.
Every season I cull 1 or 2 items from the clothing bin.