the over or under the roller should not be the issue here.
if that is a factory b7/70 installation on those two guitars, the factory needs to be ashamed of themselves.
the entire unit is way too short for those bodies
the end of the arm barely reaches the bridge pickup
the end of the arm should almost reach the neck pickup.
View attachment 183239
Never ever thought of that, thank you.This method of not going under the roller bar is a way of reducing string break angle over the saddles. Depending upon how aggressive the break angle is, saddles that are fixed can grind the strings and damage the coating There are Bigsby Models that don't even have that roller bar (B3/B30, B6/B60). This is a matter of preference to string the Bigsby that way. Just me, but one of the 1st considerations I'd have with a Bigsby is to replace the fixed saddles with roller saddles for better tuning stability and for string longevity. Metal shavings from the friction isn't good for the pickups either, the magnet attracts those metal filings & can damage the pickups if they somehow work their way down to the wire windings.