I bought a new set of chain tensioners because the old ones made a lot of noise.

The ones I replaced, that came with the bike, were plastic. I got new ones with ball bearings hoping it would get rid of the annoying sound. It did 50% but I still have this sound:

https://youtu.be/t-IRsMOcoWs


Is it normal? Can I do something about it?

I also have this "sand in the chain" sound at the back sprocket. I cleaned and lubed the chain and also cleaned both sprockets and anything around but I still have that sound. I assume it does this because the chain moves left-right which brings me to my third issue.

The chain has started to rub on the new tensioner but it's not centered, it's a lot to the right (there's just a bit of extra rubber left on the interior side). Should I try and center it or just leave it like this? And if it need centering how do I do it?

Is an extra chain tensioner like this one worth buying? Does it help in any way?

And while I'm at it, can someone recomend me a lift stand? The stander I have now is pretty lame and it works on the back wheel only.

A few questions
How dry is your chain?
How dry is the bearings on tensioner?

I still have original on my bike at 24 000 km and seems fine

They tend to be more silent when well oiled, same with chain, oil or wax, whatever you prefer

The video I posted above is right after I cleaned and lubricated the oil. Bearings on tensioners are new, I assume they must be oiled. But the sound is not coming from the chain or the tensioner but vibration on the bracket that holds the tensioner.

I get similar sound (much much less) when lubing the chain is overdue. After which is a light tic tic purring

when I clean the chain the lower roller is also cleaned. It can sometimes squeak in which case some spay lube (wd40/ GT85) solves the issue

the roller is fixed and I would say (like the top roller) stops the chain slapping too far up or down and not really a tensioner