hashamyim

Hey there, So I am a newbie to motorbike riding and have bought myself a Honda CBF1000 - yippee! Unfortunately, in order to pass the German MOT test (TÜV), I apparently need to have the 'Simmerring', also sometimes known as 'Gabeldichtringe' replaced. I am trying to find out what the English term for this is and am coming across a bit of a stoppage. Was wondering if anyone here might be able to tell what is going on from the following information. This website (in German) tells you how to replace the 'Simmerringe': https://cdn3.louis.de/content/cms/3414/3020/8968/tipp16-s56-57-gabeldichtringe.pdf The dictionary describes it as: shaft seal, oil seal, lock ring, retaining ring, rotary shaft seal... I would really like to start learning how to maintain my own bike and have bought a book, but none of these terms appear in it. Does anyone have any recommendations as to what I need to be looking at? Sorry for what is undoubtedly a school-boy question...! Regards, Hashamyim