I ran the splits from OLH; I lost ~39s in the first mile, ~49s in the second, and ~7s in the third (primarily due I think to having to avoid that damn truck!) so I suppose I was just uniformly slower on the ride. Probably didn't have fresh legs given in the intervening day I ran and went to the gym and did leg extensions and other leg stuff.
I calculated the above manually. Yes, it was a pita. I did it from the distance measurements (which don't quite line up), but I thought this may be more accurate than the altitude (which doesn't line up either). I really ought to write a program to do this!
Started planning on replacing my gearing with the SRAM rival groupset; it looks like I'll go for a compact double in the front, and an 11-28 in the back (since its so easy to change anyway); cost around $1000. Gathering measurements so far, which aren't very well documented on the internet.
For the record, my trek 2.1 has:
175mm crank arms
34.9mm front derailleur clamp
English threaded bottom bracket
Weighed in again this morning; 179.8lbs, woot.