Chain clunck coming off big cog under load

[teeonethousand]

I have a 'clunk' coming from the chain when in lowest gear under load ie going up hill. Everything changes fine up and down . I traced it to the way the chain link comes off the cog...every few teeth the chain brushes the tooth with enough tension to make it clunk as it releases it . I can see the chain twitch . This is in big rear and small front and although the chain line is obviously not straight I would still expect it to be smoother. Plenty of clearance at front derailleur.

I am taking it to lbs in the morning as I only bought it in Nov24. Revolt Grx 2x12.

Opinions appreciated but I'll update anyway after visit tmrw if anyone is curious .

 

[Dogtrousers]

Possibly the "B" screw in the derailleur. This screw governs how close the cage is to the cassette. If it undoes itself (as mine is in the habit of doing) the cage starts fouling on the big sprocket.

Also known as the "end adjust bolt" I think.

What rear mech do you have?

 

[teeonethousand]

Possibly the "B" screw in the derailleur. This screw governs how close the cage is to the cassette. If it undoes itself (as mine is in the habit of doing) the cage starts fouling on the big sprocket.

Also known as the "end adjust bolt" I think.

What rear mech do you have?

Grx 820..it's not that...all adjusted as per manual ..also tried it with bigger gap and no difference

 

[teeonethousand]

Grx 820..it's not that...all adjusted as per manual ..also tried it with bigger gap and no difference

Plus...I could understand that if the misalignment was it going onto the cog but this is it coming off at the top as it heads over to the front ring.

 

[C R]

No stiff links in the chain?

 

[fossyant]

Stiff link would be my first check