Took a shortcut this morning - a singletrack mountain bike trail that shaves a couple of km off the trip but is substantially more difficult. I've tried it before but it didn't work out too well because I was on a fixed gear with slick tires and I kept spinning out on the slippery ascents. This time I was on a cross bike (with touring tires). I still had to walk up a section of hill because I didn't gear down in time and stalled, but otherwise it was okay. With the hard tires and rigid fork, my brain felt pretty rattled by the time I got back to pavement. I'll have to time both ways to see if I actually gain anything with the shortcut.