harleyKmodel

My "Riders Hand Book" for KH models recommends 14 psi for front tires and 18 psi for the rear tire. These pressures are for 3.50 -18 tires made in the early 1950s. Adjusted for rider weight, the recommended pressures would be 15 psi front and 20 psi rear. These pressures seem too low. I understand those pressures were fine ~70 years ago because tire sidewalls were much stiffer then. My '56 KHK has Bridgestone Accolade tires that are just a few years old. The front is 3.50-18, and the rear is 4.00-18.

My question is: "What is the appropriate tire pressure for my '56 KHK carrying 200 pounds at highway speeds?

It is what Bridgestone recommends as a starting point. Low pressure generates lots of heat. Lots of heat equals tire failure.

I run 32 front 36 rear on my 61 XLH with modern Heidenau 3.50 x 18 tires. I did run it for a bit with the original sixty year old Goodyears at the lower pressures until the tread started to chunk off.