Bonneville America Forums Forums Technical Forums Accessories pirelli tires

just buy 2 new pirelli tires mt66 front and rear. like them but I'd ont know what is the proper psi in each tires. If somebody can help me. Merci

What does it say on the tires?

Not to disagree, but I'd go with what the owners manual calls out, even though the tire may be higher. My Venoms say something much higher than what the manual says, but I suspect that is meant for solid rims/tubeless setup. Just my 2 cents... 3 more and I can get a chicklet....

More than likely they will say not to exceed 44psi.
Use your judgement, I believe the Metzlers I am running say 42 psi.(I have 36 front and rear)
42 in the Metzs is as hard as a lawn mower tire(as in solid as a rock). Start at about 2-3 psi less than what is stated on the side wall, give her a decent ride and see how she handles, feels. If you like the way the bike preforms, good. Stop and check the psi while the tire is warmed up. You should be within a couple of pounds of where you started. If the psi has increased more than a couple of pounds chances are you are running the tire without enough air and may have to go up a couple pounds.
Did that make and sense, eh
Mike

I just put Pirellis on. had a shop mount and balance. Tire sats 42 and shop said to run 36 cold as they will heat up to 42 in riding.They really handle great and look good too.

The pressures on the tires are for maximum cold pressure. The pressure will increase as the tires heat up. Usually, the heavier the load the tire is carrying, the higher that the pressure should be. So, if a specification for a particular bike with max load called for max pressure in the tire (we'll use 42 psi for an example) you would fill it to 42 psi when the tire is cold. When it heats up, the pressure will increase to above the maximum recommended. This is factored in to the tire design, so you would not adjust the pressure at this time.


Now back to the question about how much pressure in your tires. Go with the manufacturers recommendation (different for SM or BA) for starters, then you can make slight adjustments (up, never go below). I run 38 psi in the Metzelers on my Speedmaster, the recommendation is 36.

Running the Metzlers on the SM, I can definitely feel when the pressures are lower than the recommended 36 psi. I don't check pressures daily, but ride every day. I will check before I head out of town, or try to at least once a week, anyway.

I tried a little higher pressure, but the ride was hard, and I'm afraid too high a pressures would cause premature tire wear (down the center of the tread).