Bearing replacement

[AndySomogyi]

I think the issue with skateboard bearings is that they are not properly sealed, and run in a dirty environment, ruining the balls and races fairly quickly. Trash would attack all bearings equally, indeed. I took your post to say that more accurate bearings do not hold up to usage as well as less accurate bearings, and thought that there might be some truth to that if they are precision ground hardened balls instead instead of ones segregated by bounce testing, which is used in many bearings to check the heat treatment and also to separate the round balls from the not so round balls. That 'might' perhaps make a difference in longevity due to a harder and smoother 'skin' on the not ground bearing rolling surfaces, with all other factors being the same. Grinding the balls leaves the surfaces pitted on a microscopic level. Maybe...

The original application of the bearings (i.e. skateboard) wheels is less important than the actual bearing style. I recently replaced all the idler bearings on my Clausing 5xxx and the original bearings only had a metal cover. So, cutting fluid, dust washed out all the original grease.

Bearings have an identification code, for example, the 6202-2RS ball bearing has two contact rubber seals one on each side of the ball bearing. The 6202-ZZ ball bearing has two non-contact metal shields one on each side of the ball bearing.

It's important to get RS style that has contact rubber seals. I'm pretty sure the bearings I used also work on skateboards.