This might be a stupid question, but..

[RGScoot]

How many bearings go in one wheel? And how many spacers are needed per wheel?

 

[btyczki21]

Two bearings
One spacer

 

[Smiler]

http://www.youtube.com/watch?v=DHLqQIyp2b0

this is the best way

 

[Rob.]

Btyczki answered it.
lockin'