Given that the full century, but not the other rides, starts with the loop down to Newburyport, one possibility I was thinking of was starting the full century, then stopping back at the start area and picking up a group that wanted to only do the half. We'd split up again in Kittery.

There's also the quarter-century option, but it's an awful lot of overhead for a 25-mile ride, and I'm kind of partial to the loop through New Castle, which that skips.