SRA change from 140g to 180g

The bubble of the Graham II is a useful tool to see in what Position the Armtube is. Very useful when another Armtube is used for comparisons...or to get a Starting point with adjustment and it is always possible to get back precisely.
It has nothing to do with the result of reproduction, cartridges are different from height, needle angle/length..
To dial a cartridge "in" always has to be done while listening. Diamonds are different and more important, the polish of its sides are different, these make the contact area where the information is.
Yes, there are those height differences from the thickness of records, but this is only one chapter. Old records have different cuts and when you listen to a old Mercury Living Presence the VTA is even some more mm down.
Happy Listening

Thanks for answer. I realize that different records are cut at different angles. Different labels with same thickness will require different SRA, best done by listening.

What I am trying to get at is that variance in optimal SRA due to different record thickness is very small. However, different labels (3-4 degree variance in cutting angle) will require large changes in VTA.

To support the above argument, I would like to verify if the mathematics is correct.

Another mute point, I suspect the visual SRA is different betw static and dynamic situation. As the record is played, the friction must exert force at the diamond and affect the static SRA. Do you think this is true?

THanks

Well, with all your findings you are on the right track.
Static/Dynamic situation
Honestly, don't make you mad with that. Do your adjustments and that's it.
Most users think, their cartridge is perfect and it can't be improved. And when they go for a more expensive one, the improvements are a kind of magic...
The diamond itself has the most influence (there are lot of different designs ( Paroc for example, Shibata...) when adjusted right, the time differences are not subtle, they are easy to hear. Next is, how good is the cartridge made internally, channel amplification/channel separation? And the polishing of the diamond...all this has a dramatic influence, A good Lyra Delos with a top diamond will beat 70% of all cartridges out there. The other 30% are based on the kind of magnets they use and what kind of cantilever/winding they have. Of course, depends on the quality of the System.
It is an interesting chapter.