There is a better 25 mm bearing set that is available on Amazon... https://www.amazon.com/dp/B076X5QZGK?ref=ppx_pop_mob_ap_share

I have a grease-packed set on standby, since they are a nonstandard size and I take the trailer across Wyoming, Utah and Nevada. But I packed the original bearings with good grease (a must) and they seem to be holding up okay.