Ibanez ZR
From Wikipedia, the free encyclopedia
The Ibanez ZR (Zero Resistance) Tremolo is a double locking tremolo system that was derived from Ibanez Edge and Floyd Rose, but it functions closer to that of a Kahler Tremolo System. The ZR tremolo offers a number of improvements from the Original Floyd Rose; it contains a heavy sustain block, locking studs, a pop-in arm and most importantly, a ball bearing-based pivot point and a removable stop-bar. This is also known as the Zero Point System.
In a traditional Floyd Rose (and vintage tremolo), the pivot is a knife edge against the pivot post; when sharpened, the pivot provides zero rotational friction. However, like any knife edge it can become dulled over time and the result is the tremolo cannot return to the zero position. In the ZR tremolo, the pivot is a ball-bearing based joint, which provides greater stability over time.
The Zero Point System acts like the Hipshot Tremsetter, in that it provides additional spring tension that is needed to return the string to the zero position. Normally both the spring tension and opposing string tension is equal, when a tremolo bar is used for a very long duration (such as excessive dive bombs), the spring tension may be compressed to the point that no tension is provided for the string. Thus, the ZPS, which equips with two additional springs, provide the needed tension and the fact that it is a stop-bar allows extreme tuning stability at the cost of having very limited scope for up-bends. Another important renovation of the ZR tremolo is that, unlike other locking tremolos, even with a string break, the other strings can still stay in tune to an acceptable level.
First installed on Ibanez S and replacing the Floyd Rose licensed Edge Lo-TRS, its ZPS system is also being used in Ibanez Edge.
An example of the tuning stability and rigidness of the ZR tremolo can be seen in the video for Through the Fire and Flames, in which Herman Li held onto his guitar with only the tremolo bar, forcing a sharp upbend as the entire guitar's weight was handled by the tremolo. During the recording of the song, guitarist Herman Li snapped one of his guitar strings, explained at time: 2:58 of this BLENDER.COM interview, but can still continue to play through his entire parts without going out of tune.
In 2008 models, Ibanez introduced derivatives of ZR Tremolo: the ZR-II, the successor to ZR tremolo; sychroniZR, a single locking tremolo with an upblocker, and Edge Zero, an Edge-type tremolo with the ZPS. ZR2 bridge with ZPS3 springs has been introduced on S Prestige series, SynchroniZR with ZPS-FX springs on the SV Prestige series, and the ZR derived (knife edge) Edge Zero with ZPS3 springs on the RG Prestige series.