It can be difficult to know if you can take the bike on the train. Lunds Naturskyddsförening has made a detailed inventory of the transport options for the cycling season 2021. You can take your bike on the regional trains in most counties. It is also possible to take the bike on a commuter train, with certain restrictions and only during a certain part of the day when there is low traffic.
Here you will find railway maps of northern and southern Sweden that show where you can take your bike on board and how dense the train traffic is on these routes.
Source: Lund Nature Conservation Association
Photo: Nora Bergslag's Veteran Railway