First, Naxos is fantastic for cycling. It caters to all levels: from those who love flats who just want to go to the beach to the mountain goats. Yes, there is lots of climbing on Naxos on nice (albeit narrow) twisty roads. Cars are not a worry as the roads are sufficiently twisty that they do not fly by you. It is easy to get off the beaten path and explore the mountaintop villages. Yannis is super. Bikes are in great shape and he is extremely helpful in suggesting routes. If you have time, rent a bike for several days, venture into the mountains and stay in the villages along the way. You will certainly experience Greek island life off the beaten path!