We have had good luck road riding on Kauai. Though the rides tend to be short, the people are still very kind to cyclists! We have enjoyed going to Poipu, the bird sanctuary, and up the Waimea Canyon on our tandem...be sure your brakes are in great shape! Hanalei is fun and so are the old cane roads My husband does some solo road and mountain biking, as well. We have S&S couplers on our bikes, so we can check them on the inter-island flights. Although there are beautiful plants on all the islands, the Orchid Isle (the Big Island) remains our favorite for rides and flowers!