For a smaller, more personal option in Ulvik if you're looking to avoid the summer hordes, this simple hotel run by a husband-and-wife team is a good bet. Rooms with a view and balcony over the river are best, but they're all quite decent, with parquet floors, plain furniture and rather dated bathrooms. Camping is available, too.
The main hotel building is across the road from the water, but the campsites and huts are right by the fjord.