Just to add a bit more confusion (!), page 24 of this document (
Metzeler US) on the US Metzeler website gives the MINIMUM tyre pressures as 38psi front and 40psi rear for the Speedmaster. The "correct" tyre pressures will be somewhere between the minimum and maximum recommended according to personal preference, riding style, type of roads used, load, etc...
As an aside, I have a T100 with OEM Metzeler tyres and the Triumph recommended pressures are the same as the ones on Metzeler's German website but different to the ones recommended in the US document given above. Go figure as you chaps would say! To be fair to Triumph, I don't know of a car or bike manufacturer that does warranty tyres.
