Traveling around Moorea by bicycle is a wonderful way to see the island. You can go where you want, you're not restricted to paved roads, and yet you can get around easily without sacrificing your freedom. That being said, this does take some stamina. Although some may scoff at the idea of being challenged by biking around the outside of a small island, the heat and humidity can make it surprisingly difficult. Once you start biking up the road to the Belvédère lookout, forget about it--this is downright difficult!
At the petrol station near Moorea Camping on Hauru Point, I was able to rent a bicycle for 8 hours for CFP 1300. This was more than enough time to bike the entire distance around the island with a side trip up to Belvédère. If you only need a regular bike (not a mountain bike), the cost is CFP 1000.
In most hotels you can rent a bike for minimum 4 hours. It will cost you 1000 CFP (8,38 EUR). Most bikes are the same. No gear and a basket on the handlebar.