Tire pressure with tubeless rim

Hello everybody,

Just a quick question about tire pressure. Since, I restored this bike, I've been inflating with 32psi the front and 35psi the back tire. I just notice today that I was looking at the tech spec of an earlier model with spoke rim. My bike is a KZ650-C3 of 79 with tubeless rim. I have the front set with a 90/90-19 and the back with a 120/90-18.
The tech spec I have says that I should inflate at 25.6psi the front and 21.3psi the back. Those value seem pretty low to me. Can somebody tell me which pressure is the right one?

Thanks in advance
Fred

32 and 35 is much better figures. 21 in the rear??? Never heard that one. Your bike has tube type wheels from the factory. The wheels have been swapped out for tubeless for sure?

RonKZ650 wrote:

32 and 35 is much better figures. 21 in the rear??? Never heard that one.

I run about 26 in my rear for a couple of reasons:

1) I only weigh 165, so I don't load it that much.

2) The tread lasts longer at lower PSI. Higher pressure will burn the center strip down to the indicators faster. Less pressure gets a little more out onto the shoulders.

I drive only on the street at speeds of 50 or below. If you weigh more than me and/or ride at freeway speeds, probably 28-30 is a better number. YMMV, always best to go with what the tire maker recommends.

My sticker calls for 28F and 32R and I weigh 190 so I run 30F and 35R. Has worked out well for 28 years.

Front and back read 42 on mine. But I'm also a heavier rider.

Thanks to all of you for your feedback.

I just checked manufacturer (Avon) recommendation and it suggest F 33 and R 36 for the Z 650 C, F (1976 - 1984).
Then if my rims were swapped from an earlier model those value are OK anyway.
I like the idea of bountyhunter to save tread of the back tire with lower pressure. On the other hand I do a mix of city and highway with speed up to 85 (according to my absolutely non-accurate speedometer) so I need to keep the pressure in the upper value. I will try your suggestion, bountyhunter, of 28-30 for while and see how the tread wear...

Thanks again and drive safe