pedaling (mountain bike) 48:46  6.11 km (7:59 / km) +124m 7:15 / km
Apparently daylight and familiarity make a significant difference, this was within a minute of doing it on foot (though I did skip a short out-n-back that I did by mistake the first time and deliberately the second). There are some spots where I still didn't bring enough skillz to get past the rocks and roots, so that slowed me down by means of a number of dabs and stops, but the bike has a definite speed advantage when it's smooth going. I'm thinking that maybe this was laid out to be done in the opposite direction, because it feels like I'm doing a lot of obstacles the hard way, so I might try turning this around. I almost did the esker section at the end cleanly, though I chose to dismount instead of trying to jump a large log that was oblique to the trail, and I also came to a complete and sudden stop at one point when my handlebar end caught a tree (but I stayed upright, maneuvered around it, and kept going). Front tire was too soft, so handling was pretty squirmy.
The algorithm still mystifies. First time on the bike it called it orienteering. Then when running, it called it running. Now on the bike again, at the same pace as when I was running, taking no splits, it still says orienteering. It's possible that I confuse it by using "pedaling" for three activities with very different speeds. Speed distribution may be a factor; although running and [road/unicycle] pedaling are done at a speed that's either steady or that changes gradually, mountain biking and orienteering have more stops.
When I got home and was taking off my shorts, I was surprised to find my wallet in the pocket. I don't remember putting it in my pocket when I was done, which means I may have done the whole ride with it in there. If so, I'm really lucky I didn't lose it.