We did the Sunrise self-guided bike ride. Pick up is EARLY, but they get you to the top of the volcano so you can get a good spot with a view. Immediately after sunrise, you get back in the van and drive out of the park to pick up your bikes, and then you coast downhill for 22 miles. Beautiful ride, going early meant the roads weren't crowded and I mostly felt very safe. Bikes and gear were in good shape too!
Note: it is COLD up top. Bring a layer or a friend to keep you warm!