Strange sound in curves: ball bearing ?

[Nickel]

Hello

Sometimes when i take a curve with slight inclination on low speed (so no much noise from engine) i notice a noise which wasn't there earlier i think. Not sure from rear or front. I think rear but with those panniers not sure.
Anyone here who has noticed the same are had problems with ball bearings or so (not head ball bearing i mean) ?
Or is it possible it's thanks to the road surface ?

For those in Belgium, i noticed it on the road to the new elevated round about behind the train station in Bruges coming from the direction of the Kinepolis.