Are bicycle rentals fairly commonplace in South India (Kerala)? Will we be able to rent bikes at a hotel or nearby? Would it be smart to rent bikes for our entire 2-week stay and take them with us if we decide to tour another area, or should we just rent by the day, as needed?
Renting bicycles is a done thing in most States in India. If you go through a known person then you may not have to keep a deposit but most cycle owners do expect a deposit. Hotels would have a list of shops that have cycles on hire. The charge is normally for the number of hours a cycle is hired. Most cycle hirers have a minimum time of half a day.