Update: new, stiffer EBC pressure plate springs installed. STILL slips!! but not as bad. wtf.
noticed the chain is a bit slack. then remembered I have a 19" rim rather than the stock 18", aaaaaand a 15/47 sprocket combo (rather than 14/50 stock) thinking I could get a little more speed out of the bike.
the physics of circles
escapes me at the moment, but I'd bet there's something about the fact that the clutch never slipped before I changed the rear rim size and put new sprockets on it that are different sizes from stock.
I'll start by tightening the chain to see how that goes. then it might be best to put it back to the way the factory intended, although I did my research before making these changes and all indications were that I wasn't doing anything extraordinarily stupid. any further insight on the matter would be helpful.