I fitted the Heudenau 150/70R17 rear to my bike today. On the sidewall it states maximum pressure is 36 psi.
This is OK for the likes of skinny Jaumev
but for a fat boy like me with a passenger and luggage I need 42 psi.
I E-mailed Heidenau in Germany and they replied thus: (Translated by Google)
If you are traveling with a passenger and luggage, you should increase the air pressure to 42 PSI to 44PSI as the vehicle manufacturer recommends.
We have changed the specification on the tire wall at the current production also accordingly.
Now that is progress.....