Oahu has a great bus system! Depending on where you plan to go, you might not even need to rent a car. Oahu Mountain Biking Trails Ka`iwa Ridge Trail Kaunala Trail Kuli`ou`ou Valley Trail Kuli`ou`ou Ridge Trail Manana Trail Maunawili Ditch Trail Maunawili Trail & Access Road Maunawili-Waimanalo Road Wiliwilinui Ridge Trail Ka'ena Point State Park Access Road to Peacock Flats Makapu'u Lighthouse Road Oahu Bike Route Map Free Weekend rides with the Hawaii Bicycling league. All you need is your bike and your helmet. (Waivers are required if you are not a member of the organization.)