Thats right. It's called hydrogen embrittlement: The plating process causes hydrogen atoms to get lodged into the crystal lattice of the base metal preventing them from slipping. Embrittled spokes will snap like a dry twig. Materials folks discovered that by baking recently chromed parts for a while at several hundred degrees they could drive off the hydrogen returning the base metal to it's former ductile state. I didn't think anyone would care about the reason so I kept it short.