It is closed to bikes for the month of March for mid-season.
This trail makes for a ~six-mile loop around the Fells Reservation. Since it goes around the reservation there are no real "shortcuts" once you get going.
It has singletrack, fire roads, and occasional difficult obstacles—a little bit of everything. Start to stop is about a one hour ride, yet total time for us was just under two hours. You'll encounter hikers (some with dogs and/or strollers) as well as other mtbers, so there will be times you'll need to stop.