Four laps in and with warm, although worn, tires, I started upping the pace a bit on the stupidbike (05 GSX-R 1000, Scott Miller motor), and then suddenly ZING! go the revs. I captured this on video:
http://www.vimeo.com/6527535 The bike literally ripped the chain in two, one of the links was torn in half. No damage to me or the bike, a small miracle.
Note comments: I'm aware that an impromptu wheelie knocked the camera down... first time I've tried to use it, but it at least captured the sound of the chain going.
I spent the next two sessions riding my bud Martin's CBR1000RR. Now I know just how spoiled and lazy the stupidbike has made me. A very good standard street bike feels horribly balanced and unresponsive compared to the track bike. I will stop complaining henceforth about any of its perceived shortcomings.