Taking into account both drive safety and mechanical stresses, is a wheel imbalance of 50 g (~2 Oz) a safe threshold for a generic road motorcycle? Does the figure change if we consider motorcycles capable of more than 300 km/h?
By "50 g imbalance" I mean such an imbalance that can be corrected by applying a weight of 50 g at the appropriate location on the rim.
I had a guy in a tire shop telling me that balancing motorcycle wheels after a tire change is basically wasting time and balancing weights, whose glue residues are sometimes very annoying to remove.
He added that, on a common road motorcycle (17" rim), a weight imbalance up to 50 g does not cause any issue, and that modern processes for wheel and tire production ensure being well within that tolerance.
I was skeptical, but I could not to find official data from manufacturers, so I secured a 50 g rock to the inside of my front wheel and drove up to speeds reasonably achievable on open roads. I was surprised of not being able to tell the difference in any circumstance, in particular I could not feel any added vibration, even if I was really paying attention.