Neu 1521's bearings? help
 

May you tell me, please, the size and spec of the bearings of this motor (Neu 1521 1Y the version with only 4 M4 holes in the front)?
Abec value?
Do you know if i have to upgrade to ceramic or better ones?
In that case where i can buy new ones?

this is my baby on a LST2 Muggyfy project.

http://i361.photobucket.com/albums/o...by/NEU1521.jpg