Why the resistance band on the five valve tubas?

It works well, is simple to replace, is easy to adjust for more or less tension. I During testing two F tubas, one with a clock spring and one with resistance bands were compared by over 100 players. For action and feel, every player chose the rubber band. Admittedly many players think it looks like a proto-type. Since production has begun players who try the BMB system more often than not say they like the feel and the simplicity as well as the ability to adjust to their personal preferences.