one leg slightly longer than the other so your kness hits the knee roll in a slightly different location on that side and rubs the johdpur above the knee pad?
using one leg more than other riding? got somthing on that leg of your jods that wears the material? or someone playing games with you lol and making holes in them at night when your not looking lol?
Im going to monitor myself very carefully next time I ride to see if I can suss out whats happening. Have to say dont ride more than once a week so not convinced its riding!.