Question regarding VersaBlock vs Plastic Clamping Bearing Block

FIRST General Forum
1

Besides the obvious (one is metal i.e. stronger, and one is plastic), are there any other differences in form or function between the two options?

Do PCBB need a Cam for chain tensioning or is it built in (because plastic) or do they not support that function?

Thanks!

2

PCBB is for adding (a) stage(s) to a PCGB. I have drilled through the tube to fix them in place, and tensioned the belt (or chain) using a Versablock at the other end.