I have an app for correct tyre pressure. It's admittedly a bit of an ask when daily weight fluctuations result in fractional values, but you have to be precise about these things. Stop after each sip from the bidon, re-calculate. Take bike and pump into the toilets at the cafe stop and adjust. That ineffably pleasing extra precision when cornering and a jolly good feeling all round of doing the right thing make the small bit of additional effort involved well worth doing it.
I have an app for correct tyre pressure. It's admittedly a bit of an ask when daily weight fluctuations result in fractional values, but you have to be precise about these things. Stop after each sip from the bidon, re-calculate. Take bike and pump into the toilets at the cafe stop and adjust. That ineffably pleasing extra precision when cornering and a jolly good feeling all round of doing the right thing make the small bit of additional effort involved well worth doing it.