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Just a reminder now that its cold we need to check our tire pressure. Got warmer here this weekend so took out the bike but check the tire pressure first. They were both pretty low. :bikerguy:
 

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Mississippi Cajun
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Same here. Low pressure every time the weather changes around here. Makes me glad to have that compressor in the garage.
 

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Just a reminder now that its cold we need to check our tire pressure. Got warmer here this weekend so took out the bike but check the tire pressure first. They were both pretty low. :bikerguy:
Not just for the motorcycles, but our 4 wheel vehicles as well.

Had TPMS flag low tire pressure on my truck, checked em and sure enough, all 4 tires were low by atleast 5 lbs.
 

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Retired citizen
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Not just the bike either ! Cars, trucks and anything ya use that's got air tires on them.
I just did my car and truck, dang they were both down and not even either ! I try to keep up on it because I've got a good air compressor at my shop. It's just got to do with getting 'er done ! Gotta get in the habit of checking all the time.
 

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Edslow; thank you for bringing this forward. I don’t want to hijack your thread but I thought no new thread is necessary.

Tire pressure is one of my curiosities about my first Harley (RKS) to be delivered late January or early February. The owner’s manual says 36 psi front and 40 psi rear. This is the first time I encounter an official recommendation that does not distinguish between solo rider and two-up, or light and full load. IMHO, the contact patch of the tires; especially that of the rear, would change substantially in accordance with load.

Do you guys/gals take this as a general recommendation upon which common sense should be based or, do you think that this means no alteration is recommended as long as the gross vehicle weight is not exceeded?
 

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Edslow; thank you for bringing this forward. I don’t want to hijack your thread but I thought no new thread is necessary.

Tire pressure is one of my curiosities about my first Harley (RKS) to be delivered late January or early February. The owner’s manual says 36 psi front and 40 psi rear. This is the first time I encounter an official recommendation that does not distinguish between solo rider and two-up, or light and full load. IMHO, the contact patch of the tires; especially that of the rear, would change substantially in accordance with load.

Do you guys/gals take this as a general recommendation upon which common sense should be based or, do you think that this means no alteration is recommended as long as the gross vehicle weight is not exceeded?
I run 36/38 and 38/40 for two up . :)
 

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With the size tires your bike has, and the weight of the bare bike, the contact patch doesn't change as much as you might think.
Starting with the factory pressure until you have had a chance to "feel" it out, is the best approach. They don't just dream up the pressures listed in the manual, they do a bit of testing to come up with their recommendations.
 

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...They don't just dream up the pressures listed in the manual, they do a bit of testing to come up with their recommendations.
I would like to benefit from the outcome of their tests but yes, I can experiment on my own. I tend to believe that sidewall stiffness and contact patch area play an important role in the handling of any motorcycle. Both are affected by the pressure in the tires but I get it that this effect may be negligible on a heavy Harley with fat tires, no matter what the load is (within permissible limits).
 

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Car/truck tires typically lose 1-2 lbs per month thru normal movement of air inside the tire moving thru the rubber compound....the mixture of air molecules are smaller than the pore space in the rubber so we lose air over time, even if not ridden. So if its been a couple of months since riding/driving and cooler temperatures (I think I read somewhere 1bl per 10 degrees below 60) and its easy to see why low tire pressures pop up on your gauges or TPMS sensors. Nitrogen molecules are larger than the pore space in rubber and that's why they do not lose pressure over time with a nitrogen fill. If you choose this route be sure and use a trusted source....has the ability to be a scam as I have witnessed in the auto industry.
 
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