uxcell6816-2RS Deep Groove Ball Bearing 80x100x10mm Double Sealed Chrome Steel 61816-2RS Bearings

Very smooth rotation and accurate dimensions. Used for 3D printed rotary microscope stage. I'm very happy with this product and would certainly buy it again.

Quality bearing in hard to find size.

well packaged (protective oil, multiple bags), smooth operation

These will fit a cfmoto uforce 1000xl clutch bearing

Terrible bearing. It does not spin freely and has a ton of friction. At any amount of speed I would imagine this thing heating up like crazy. Not worth buying at all.

good dimensions just so oily on the outside

The bearing had a decent amount of friction when I got it. At first I thought it was because the lubricant inside was old, but I took it apart and noticed the seals were slightly bent, which I think is making them rub against the balls inside, thereby causing the friction.

I should have know better, but I thought what the heck, at $15 per bearing it's a steal. Well, After opening these bearings and giving them the old spin test I threw them right back in the box to return them. I'm not sure if the manufacture of these bearings really thought that using sand as a lubricant was the best idea.... These bearings are super scratchy, and when spinning produce a rhythmic noise due to the extremely poor quality control.