So , first of all i have a te570 '01 I couldn't find the right part of this forum to post my problem in so I think it's best to put it in the 610 part of the forum . sorry if it's in the wrong place . :s I did introduce myself months ago but i don't think anybody remembers me xD But I will explain to you guys my problem : I was riding with the bike doing normal stuff nothing fancy like doing a wheely or something just normal riding on the street 3gear 50km/h when all of sudden I started hearing this grinding noise (the same noise you hear when you're using a lathe or a mill ) a grinding noise (not tik tik tik tik tik tik ... but schhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhrrr you know ) not loud but because i was riding with low rpm i could hear it . nobody else could hear it and everybody said i was nuts because they didn't hear anything but ,I decided to go home and when I started checking everything i noticed this (see picture) ... there is a weird ring on the inside of my flywheel cover ... so i think the nut that 's on my flywheel is rubbing against my cover (that would explain the weird noise)... also : the bike runs great 1kick and he starts everytime , he still got all of his power he drives normal , no problems with shifting , no clutch problems he still is very fast etc. there is nothing wrong with the bike except for this problem with the cover . also when i tried to loosen the nut with a pneumatic wrench it did nothing it doesn't move at all ... so it isn't loose because i can't even loosen it . thank you very much if you took the time to read this and sorry if there are alot of mistakes in this text but my native language isn't english Chiel