Originally Posted by ragtoplvr
Bugs end their lives on the fork tube, and some bug residue gets past the seals and dissolves into the oil. There will be some water too.The bacteria eat it. Bacterial farts are pretty nasty.
That's why cleaning all the debris from the sealing surfaces of your fork legs every
time you ride prevents that from happening.
I change fork oil frequently, by the calendar (2 years max), and have never had any funky odor or debris once the OEM fork oil was replaced. The fork seals on my primary ride are about 15 years old, and they're both very happy.
I live in Orygun, and ride in the rain a LOT.
I've yet to see any evidence of water in any fork oil removed from my bikes once the OEM swill has been replaced. There are always a few tiny bug bits, but no milkiness or any other indication of H2O in the wrong place.