Pacific Northwest - Biking on Kauai?

I will be on Kauai next fall (Sept. 15 I think) for a wedding and wanted to do some cycling. I looked on the internet, but mostly all I saw was tours. I don't really care to spend $90 to have someone drive me to the top of a mountain/hill so I can coast down. I guess I would like to ride along the ocean, maybe into the mountains/hills.

We haven't pick a place to stay yet, so I was wondering if certain areas have better riding (traffic/roads) than others. I prefer road riding over mountain biking, if that helps. This could dictate which part of the island I would like to stay.

Also, should I bring my own bike or rent one?

Thanks in advance for any advice.

Roads on Kauai are awful, little to no shoulder and much traffic. It's the worst island of them all for cycling. The only ride Ive done is from Lehue to Kokee State Park, it wasn't too bad, but be careful!!!. Just stay off the road from Kaapa to Hanalei. Go sea kayaking instead of cycling, or hiking on the Na Pali Coast.

We spent 10 days in Leihue Nov 05 and I took our Double Vision recumbent tandem. After a morning run up through the Golf course with my wife I would then cruise for Cruise ship passengers to give them a free ride. The Edgar Winter's tune comes to mind. After my kids got up I would take them for rides and usually do a run to the grocery store. Leihu is at sea level and it is a climb out either way but I enjoyed finding less used roads then the main drag and avoided rush hours for cruising. Met some locals who showed us a very cool water falls that we could jump off. I had planned to travel farther but stayed around Lehue mostly. I agree that the roads are narrow and shoulders are few and far between but I would have hated to rent a car while I was there. I would definately take my bike with me again. I have had it on Kona, Oahu, and Maui, in past years and it has heightened my overall enjoyment of my vacation.