2010 that I bought a couple years ago.  This wasn't evident then and I've not added any brake or fork fluid.  This started showing up about six months ago.

I wonder if the top of the right fork is leaking fluid?  It would make sense as the bike leans to the left so it would run down to the stem nut as there is some dampness there.  Make sure the brake line isn't leaking anywhere above it as well.   Try to get some of the fluid below the stem nut on your finger and smell it (Yeah, this does sound crazy and I'm not joking).  If it has any kind of petroleum smell it's probably fork fluid.

I haven't noticed any fluids anywhere in that area, but I'll look/feel/smell more closely.

I haven't noticed any fluids anywhere in that area, but I'll look/feel/smell more closely.

I don't think that anyone has reported or showed a picture of that kind of 'damage'.  Double check the brake lines and master cylinder as well for leaks.

Doesn't look like corrosion beneath the paint -looks as though the paint is "wrinkled" pointing towards previously mentioned brake fluid leak. Also-by zooming in on the picture I can notice a small amount of fluid right around the upper bearing area. I'm going with the brake fluid leak.

I'll check that in a minute and see if it is brake fluid.  Hadn't noticed that before.

Have you or anyone else ever changed the brake fluid?


Could be that some spilled there and then wasn't wiped up correctly or soon enough.
Then when in the sun it started the slow process of dissolving the painted or coated surface.  So you might not see a leak now.
Could have taken up to a year for this to show up.  Just saying that is one possibility.

When did you first notice it? and how long has it been there?