I have a 2009 Triumph Tiger 1050 that gets ridden very rarely.
Took it out this morning and the front brakes felt very ineffective - looked at the wheel and it seemed like there was a bit of oil on the sidewall of the tire, and the brake rotors (at least on one side). Not a river, but enough to wet a 3-4 inch section of the sidewall.
I cleaned it all off and left it sitting with some clean shop rags on either side and wrapped around the fork. Checked the brake bleed valve and where the line connects in - all could tighten up a little but not crazy loose. Forks had a light coating of oil & dirt, nothing too crazy, but not bone dry. Pumping them up and down hard a few times didn't produce an obvious leak.
Any suggestions on how to diagnose further? I know I will need to soak pads & rotors in acetone and/or replace pads, but I want to find the source of the problem first.