Roller bridges are commonly used as an upgrade to Tune-o-matic bridges and vibratos on guitars to reduce friction, therefore increasing tuning stability and lowering the chance of string breakage.
But you might be worried that doing this will affect the tone of your instrument. Well, fear not, most guitarists agree that there is no real tonal difference between a traditional Tune-O-Matic saddle and a roller saddle.
Why Should You Buy a Roller Bridge
Tune-matic bridges feature a rather thin edge that makes contact with the string. This arrangement is great for sustain, but if the one or more of edges are a bit sharp it can lead to string breakage, especially if you do a lot of bending.
Rollers saddles eliminate that issue. When tuning, the contact point is round, not an edge, therefore, the rollers turn as you're tuning strings to pitch. Whereas, when you are bending strings, a roller bridge makes the return to pitch more accurate than a standard tune-o-matic bridge.
However...
Bridge friction is only one of several factors that can cause tuning instability. And some roller bridges will be loose and affect the stability. Therefore upgrading to a roller bridge won't magically solve all your tuning instability problems.
You could also have other issues, such as a sticky nut, bad string trees, malfunctioning or old tuning machines, or even new strings that are still stretching, etc.
Therefore, to achieve the optimum tuning stability, it is also recommended that you change the guitar nut and lubricate the slots in it just before each performance. If you want to go one step further you can also add locking machines, then most bases will be covered.
