had a few of this make of bearing and for me their great but what i do is with a screwdriver flick the plastic pegs in and remove the inner bearing wipe off the grease and re pack the bearing with the good molly grease and re fit the bearing cover now they are fullp packed with good molly grease they will last for years the skf bearings are crimped and you would need to use a junior hacksaw to remove the crimped ring but the first line one are easy to open just with a screwdriver