I guess you talk about where to buy bearing spacers, right? MBS doesn’t use any so you have to DIY. I cut the spacers from a tube for Rockstar II, can check the length later.
Trampa Superstars use 17.8mm and Hypa 18.2mm bearing spacer.
For real? I didn’t know that, gonna check it after work. Trampa sells 12mm washers (and 8+10mm).