Wow, on a whim I did the last 70 miles of the STP on my Soma Rush (46x17) I am horendosly out of shape and did no training, think I averaged about 15mph, I was supposed to ride it with my friend but he dropped me after a bit so I just kind of poked along, it was fun but I am kicking myself for not doing the whole thing.
I know that with a little bit of training I could have just done the whole thing in one day, oh well, live and learn, maybe next year.
I got ALOT of compliments from people, it was fun but I always had to explain "oh I only did 60 miles of it" people were all still really cool though.
at one point a pack of a few guys passed me on SS or fixies, one of em was a rivendale quickbeam and thats all I remember .. the guy said something like "yeah single speed single speed" or something as he went flying by me..
I dont know if I saw any others, I was keeping my eye out, there was a group of guys from seattle that "pirated" (rode without registering but didnt eat any of the food or anything) the ride, saw them but none of them were on fixies... I was surprised at that
all in all it was alot of fun, I wish I would have done the whole thing