That's about the same as my commute. A week ago Friday I rode it on my 1973 Schwinn Varsity to work (and on the Critical Mass ride afterward, almost 50 miles for the day) and I somehow made it.
Just ride, baby!
As for the Marathon, I no longer have mine either. I suffered a mishap at the beginning of a charity ride and bent the derailleur hanger and dropout all to heck.
__________________
I stop for people / whose right of way I honor / but not for no one.
Originally Posted by
bragi 
"However, it's never a good idea to overgeneralize."