Flying is the best option between Malabo and the mainland. There are several national carriers with offices in Malabo and Bata.
There are no facilities to hire bicycles. However, if you want to take your own, roads are generally in good repair. The frequent heavy rains could present a problem, though.
In Rio Muni there is an interprovincial bus service, Kassav Express. However, shared taxis are more comfortable and easier to use.
Car & Motorcycle
Roads are excellent in Equatorial Guinea. There are tolls on all roads outside of the cities that cost CFA500 per vehicle.
Car hire is expensive: expect to pay at least CFA70,000 per day, and there's a hefty deposit of around CFA250,000. Europcar and Avis have offices at Malabo airport. Autos Litoral has a desk at the Ibis Hotel close to the airport and another office in Bata. They provide drivers if required. If you are driving yourself, you will need an International Driving Permit.
In towns and cities, there are plenty of shared taxis to hail for short journeys. They are usually white with a coloured stripe along the side. They will hoot if they're free, and if they are not going in your direction, will simply drive away. For longer journeys between towns or for a trip around Bioko Island, you will need to negotiate a price with a taxi driver, or bag a seat in a shared taxi.
There is no railway in Equatorial Guinea.