Rupes 15 vs Rupes 21 w/5" backing plate

[Loach]

Thanks for updating the thread with your experience. I have heard that the vibration of the 21 with the 5" backing plate is more noticeable over the 15, which in other threads has caused many people to recommend the 15 over the 21 if one plans on mostly using 5.5" pads. I don't have experience with either, I was wondering about the vibration factor and looks like people have mixed experiences while comparing the two setups.

[expdetailing]

Yeah, I'm not sure why others complain..Maybe they are not centering their pads? Or, the pads they are using are not robust enough for a long-throw?

[Woob]

It varies on the setup. I run the 21 Rupes + 5.5 pads just because I prefer a small diameter for working in certain areas. It costs much more to have both sizes of pads which is why some people stick with a certain size. 21 is built for 6inch pads, so slightly changing the balance can affect the feel for sure. However I find it more important on which pads you are using. A stiffer pad, velcro system, or thickness are really big variables.