Current Projects chat and miscellany

Normally yes, and any freshly exposed aluminium should just re-form its protective layer then stop corroding, but that clearly isn't happening here. My guess is there's a galvanic cell formed there when it's wet and the aluminium is acting as a sacrificial anode to protect the more noble brass nipples and steel spokes.

(The classic example of this is when people try to fix stainless steel sheeting with aluminium pot-rivets - when exposed to weather the large area of less electronegative steel makes the small rivets rapidly corrode away. But in your case the small area of nipples and spoke versus the large area of rim should be working in your favour, only the rim's protective anodisation is too good - it's focused the corrosion to just where the nipples have damaged it.)

I bow to your electrochemical wizardry, but why has it happened to only these eyelets? I refer back to my initial theory, of the eyelet's bulging under spoke tension. I think they should be cleaned up and examined.