Join Date: Aug 2009
Location: Washington, the state
I don't think anybody except maybe a tire engineer knows what is the "best" tire pressure to run. Go by the sticker on the swingarm or the listing in the owner's manual. Not that for vehicles after (I think) 2009 this is the pressure required for the max load the vehicle is made to carry. Earlier models often had a sticker that showed both the pressure required for normal loads and the pressure required for maximum loads. These are always cold inflation pressures.
The pressure listed on the tire's sidewall is NOT the recommended pressure. It is the minimum required pressure to carry the max weight the tire is made to carry, usually more than the vehicle is made to carry. Depending on the wording, it often may not be the maximum cold inflation pressure that tire can handle.
The tire pressures listed on the VIN sticker on the bike are the minimum pressures required to carry the maximum weight the bike is made to carry.
Lots of mention of the weight on the tire. Tire makers have load / inflation tables that show the cold inflation pressure needed to carry any weight on a certain sized tire. They don't share those with us, but perhaps someone can telephone a motorcycle tire maker and ask for the load/inflation table for the sizes our stroms use. It's not too hard to weigh each end of the loaded bike, maybe with a helper. Even my bathroom scale goes up to 400#. Set boards so the bike rolls straight on the scale and the other end is at the same height. Sit on the loaded bike and read the weight. Use the load/inflation tables to know the needed air pressure.
Wait, there's more. Tires need to flex to generate normal warmth for best traction--cold rubber doesn't grip well, and very hot rubber doesn't grip plus wears really fast. The amount of flex depends on the air pressure and the weight on the tire. A bit less air in cold weather let's it flex more, get warmer, and grip better. A bit more air in hot weather let's it flex less, don't get too warm, work well. And, to a point, more air saves a bit of gas and slows tire wear. And, more air makes the tire run harsher--the tires are the first link in the suspension chain.
So, what cold inflation pressure to run, 1-up? Start with the sticker pressure for 1-up riding (for older bikes) or the sticker front pressure and 3 psi more in the rear for newer bikes that don't list two pressure ranges. See how it works for you. Try 2 psi higher in each end and see how you like the results. And 2 more. If 2-up, use 41 in the rear--the passenger doesn't put load on the front tire. (My Vee2 lists 36 front and 41 rear regardless of the load on the rear. I like 36 front and 39 rear.)
"Older people who are reasonable, good-tempered, and gracious will bear aging well. Those who are mean-spirited and irritable will be unhappy at every period of their lives.
"Let each of use properly whatever strengths he has and strive to use them well. If he does this, he will never find himself lacking."
Marcus Tullius Cicero
Last edited by PTRider; 06-06-2015 at 01:40 PM.