Preface: In another thread I surmised that the undesired string buzzing (high-frequency rattling) of the old style Rick roller bridge might be due to saddles that move (wiggle) easily. The current standard bridge saddles have a spring on each saddle assembly which not only keeps the saddle in place (obviating the need for a nut on the adjustment screw as with the roller bridge), but more significantly, also places a steadying pressure on the saddle, preventing it from wobbling, possibly creating a rattle/buzz. The springs for the standard bridge are readily available and can be installed on the roller bridge. I noticed that each roller of the roller bridge has a rather shallow, cut out channel for the string to lie in. These channels are the same width and depth throughout all six rollers on their respective individual saddles; I measured the string channel width to be about 0.030 inches and close to 0.020 inch in depth. So, the thickest string used sits in the same roller channel as the thinnest string does.
I have a generic roller bridge of a more modern design, one used on guitars whose owners have rarely, if ever, complained of roller bridge buzz. I compared the two, more specifically, the individual rollers on each this modern roller bridge and the old (vintage) style Rick roller bridge. The modern rollers have a relatively wide “V-shaped” channel, which automatically accommodates a variety of string thicknesses, and is also deeper in depth. Strings that exceed 0.030 inches in width are supported only by the sharp edge of the outer surface of the string channel of the vintage roller. The thicker the string is on this, the less lateral support that is offered. With the channel having parallel walls, there is less tendency to allow string tension to force the vibrating string (back) into the string channel (enhance seating of the string). I surmise that the vibration of a thicker string causes it to laterally leave the channel alternately as it vibrates, creating the buzzing as it bounces left and right. The “V” shape of the modern roller is deeper than the channel of the vintage roller and its slope allows for a vector of downward, seating force which tends to maintain the position of the string on the roller.
(I discovered that the saddles/saddle assemblies of the "modern" bridge did wiggle when I checked them with my finger tip. So, necessarily, I've had to discard [mostly] my previous theory that "loose" saddles were the main cause of roller bridge buzz.)
Here are some photos. (Someday I’ll have to get a camera that can take nice macro shots.) Take a look through them and decide for yourself if the design differences between the vintage and modern rollers could be a cause, or at least, a contributing factor to roller bridge buzz. I don’t see an easy fix for this. The vintage rollers could be replaced, but at significant expense and effort. Reports of roller bridge buzz being controlled with grease or oil on the rollers may be the only simple remedy, and I’m not sure exactly why this works. It’s certainly worth a try.
This site, I found, can no longer accommodate photos with embedded links to a photo hosting site that allows concurrent reading and viewing of photos in a posted thread. The attachment facility does work, but I find it will accommodate only a maximum of three (3) attachments per reply. I’ve had to place these 12 photos in multiple replies for that reason. (I used some old bronze acoustic strings for my photo props.) Take a look, if you want. Remember the title of this thread… it’s only a theory. What’s yours?
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File comment: Vintage style Rick roller bridge
1. Rick Roller Bridge.JPG [90.68 KiB]
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File comment: Vintage roller. Note the string channel design.
2. Rick Roller - no string.JPG [66.59 KiB]
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File comment: Vintage roller with .024 string. This string seems to lie within the channel OK.
3. Rick Roller - .024 string.JPG [73.35 KiB]
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