I've been having this issue with my chain loosening after I correctly tighten it after a few 100km, it's sagging again. The sprocket and chain are fairly new, done by the previous owner, rear sprocket is 2t bigger than stock
I've finally noticed that the chain tensioner is allowing movement. Before I'm asked, yes I've tightened up the pinch bolt.
I've adjusted the chain a few times and this keeps happening.
Has anyone else had anything similar happen?
This is just after adjusting the chain

and after doing usually around 200km or so, I can actually notice it when riding, it's less responsive and the chain hits the swingarm when going over bumps.
