Originally Posted by
T Stew
But if the outer black was not hard-anodized then wouldn't the grey hard-anodized surface show through somewhere where the black is worn? The whole brake surface on one of the rears is completely worn through and partially on another. I'm not personally familiar with the process but are you saying anything that is HA and is a different color than this grey actually has another layer of color separate from the HA? Like for example my flashlights that are HA black?
You can definitely dye hard anodizing, usually black because the dark gray/green underlying color doesn't take colored dyes well. However, hard anodizing is still only .002" (0.05mm) thick nominally which isn't much. And while 'hard' it isn't impenetrable. Road grit is plenty abrasive enough to wear through it over time.