While Sweden has long, dark winters, cycling is a national pastime when weather allows, and a good method to get around many cities and islands.
Most Swedish cities have excellent bicycle paths, and renting a bike can be a quick and healthy method of getting around locally. Some cities have bikes for borrowing. Inter-city cycling is a good option for the experienced cyclist. While cycling is not allowed on motorways, most of them have a parallel old road without the heavy traffic.
Inter-city cycling is generally quite possible. Some railway lines have been converted to bike roads, otherwise intercity bikeways are few. Minor roads are usually paved, low-traffic and can be quite suitable for cycling. There are two national networks of signposted routes along mostly minor public roads: "Sverigeleden" and "Cykelspåret".
Stockholm has a bicycle rental system called Stockholm City Bikes. Some bike rental is available at bike shops in larger cities and some coastal resorts. Some local commuter trains (Stockholm free, Uppsala, Skåne for a fee) allow bikes being taken as-is on board during non-rush hours; otherwise a bike should be folded and put in a bag to be brought on board trains.
Unlike most European countries, bicycles are not allowed on mainline SJ trains, except for foldable bicycles, which count as regular luggage. They are allowed on most regional trains, not branded as SJ.
Vätternrundan or Vättern runt is an open 300-kilometre race for amateur cyclist, starting and finishing in Motala, as a leg of the Swedish Classic Circuit. This race is quite popular; usually sold out one year in advance and with a somewhat hefty entrance fee (1500 SEK). Randonneur long-distance (200 to 1000 km) amateur races / rides are also organized in cities from Malmö to Sundsvall, and usually only require registration at the start or some days in advance.
There are some legal demands to driving a bicycle in Sweden. The bicycle must have breaks and a working bell. Lighting and safety reflectors are mandatory when driving in the dark. Bike helmets are mandatory for riders under 15 years old.
The shoulders of main roads are often used by cars to allow easy overtaking. Where there is limited sight (such as in hilly landscape or dark evenings) this is a severe risk for cyclists. Using a bike lane is officially mandatory if it's parallel to the road, but many exceptions exist. If the bike lane is not well-kept (for example, full of snow or debris) it's better taking the normal lane.
Cold weather can discomfort cyclists during cold seasons. Roads are occasionally covered by snow and ice in winter (November–March in Stockholm), and ploughing might be deficient. Studded winter tires are recommended.
When cycling outside urban areas, it is advisable, but not mandatory, to wear a reflective vest. Especially when driving on roads that go through forested areas, where the play of light and shadow may camouflage the appearance of a cyclist on the road to other drivers.