Petit Arago Gite has plenty of room for up to 6 bikes in the garage. You can visit Carcassonne and leave your bikes in safety while you explore the city.

Whether you arrive with leisure bikes or racing bikes you can store them in the garage and visit the Castle or Bastide on foot. 

E-Bikes can be rented if you would like to have a cycling experience in Carcassonne. 

https://www.tourisme-carcassonne.fr/commerce-organisme/location-cyclolibre/

You can also rent bikes from https://www.giant-carcassonne.fr/fr/location-velos-carcassonne