Thruxton 2013 Triumph Thruxton 900 Air Pressure On Tire Sizes 110/80/18 And 150/70/17

It all depends on the tyre. Different tyres have different recommendations. But it should give you a starting point in your hand / service book

 

Can't help you as I run standard sizes
110/90-18 33 psi
130/80-17 41psi
your wider rear will probably be a little less.
Can I ask why you chose the wider tyre?

 

My Ducati and my Striple both have exactly the same size wheels, rim widths and recommended tyre profiles. The Duke being 20kg heavier.

Checking the user manuals against the tyre manufacturer’s recommendations for the Dunlop Qualifier 2s that I have on the Duke I found they tallied.

Now for the conundrum, remember the Duke is the heavier bike with 33 front and 36 rear. Whilst the Striple is 32 front 42 rear which is the lighter machine.

Not even Dunlop’s “tyre doctor” could explain this difference. So, you will find many machines have 42 psi recommended for the rear tyre pressure which is absolute sphericals.

 

For road tyres I go by the +3psi rule of thumb.

After a good half hours non stop ride the tyre pressure should increase by 3 psi.
If it’s more then the tyre is slightly under inflated and running hot, if it’s less then the tyre tyre is overinflated and running cool. Simply add or subtract air to achieve the desired pressure.