I live just across the Belgian-Dutch border and visit Brugge several times a month, so a quite familiar visitor.
It’s about 7km from Brugge to Damme, so an half hour one way biking. Fun if there is no or a bit of wind, not so with strong head and even side wind. Hiring an E-bike (think is possible) can make in that case life easier and make it also more easy to explore the countryside further north to Oostkerke and Sluis / St Anna ter Muiden just across the border.
The cobblestones used nowadays in Brugge are more flat and more comfortable but still can cause physical discomfort. Not all streets have cobblestones, the Langerei is the asphalt street at the leftside of the canal deep downtown Brugge leading to Damme. It’s a busy street, so take care. Depending where you get the bike from, think about riding 10 to 15min. in discomfort before hitting that street. Outside Brugge the bike pathes are seperate, you can also cycle at the westside of the canal having lesser and (hopefully) slower driving traffic.
Tomorrow will start the famous and notorious cycling race Paris-Roubaix. With it´s long and many stretches of old fashioned cobblestone country roads makes it to one of the toughest races on the calendar. At the final stage of this “Hell of the North” the cyclists run over 40km/h over the cobblestones chasing that prestigious trophy.............a cobblestone.