Tire Presure

[Guest]

Old question I am sure but I will ask it any way for the new guys you understand

Replaced the rear tire this week the shop says to run it at 42 psi while the bike says 36 solo 38 two up. The tire says max load 650 pounds 41 psi. So which one is correct? I want to get the best mileage I can but dont want to sacrafice preformance.

Thanks

Pat

[Steve]

The first part of the answer is easy:
The tire says 'Max pressure 41 psi'. Don't start at 42 psi.

Now...what is the correct pressure?
Start with 36 psi. Go for a ride. Warm up the tires thoroughly, about 50 miles will do nicely. Measure the warm pressure, it should go up 10%. If it goes up more than 10%. your starting pressure was too low. If it goes up less than 10%. your starting pressure was too high. Adjust pressure about 2 psi when tires are cold again, then go for another ride (darn).


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[earlfor]

Riding solo, I run 34-36 psi front and rear. Two lbs more if riding two up or loaded with a lot of gear for a trip.

E.

[denydog]

I'm staying out of both, type of oil , and tire pressure discussions. :-D

[Gravity Tester]

I'm staying out of both, type of oil , and tire pressure discussions. :-D

Please dont Iam not looking to stir things up but any educated guess would be great.

Earl what are you getting for Mialeage? or any one else for that matter?

[Billy Ricks]

Steve gave you a very close to correst answer. There is no preset pressure, and don't go by the maximum pressure stated on the sidewall. That's for a maximum weight load.

I once read an article by a BMW tech. He said that the hot tire pressure should be 3 lbs more than the cold pressure. Too much air and the tire will never heat up properly, won't have great traction, and will wear the center of the tire out quicker than it should. Too little air and the tire will heat up too much leading to a tire that goes away after it heats up and will wear out sooner than it should.

[twistedwankel]

Replaced the rear tire this week the shop says to run it at 42 psi while the bike says 36 solo 38 two up. The tire says max load 650 pounds 41 psi. So which one is correct? I want to get the best mileage I can but dont want to sacrafice preformance.

The only unsafe tire is a new one or underinflated one. It takes 50 miles not more than 55 MPH for the cords to take a permanent set. Even if the tire is speed rated at 155mph. Once it has been punctured it loses it's speed rating and must be discarded or run slower.

Unless you have a good tire gage 1psi isn't going to matter much as the cheap ones usually read a tad low anyhow.

The shops usually inflate the rear tire to "cold" max because they are concerned you will go out and dump the bike at speed with the mold release compound that needs to be worn off the wearing portion of the whole tire. Not just the bottom.

Continuous High speed running requires higher pressures of around 3psi more than normal to keep the tire from overheating (excessive flexing).

For normal use I would never run at high pressures as the bike beats up my kidneys on normal roads/bumps. Race tracks are smooth. Granted you will slightly improve fuel economy at the sacrifice of comfort. Personal preference. I really didn't buy a bike for mileage - just grins. All tho' I do consistently get 48mpg on my 750.

Also. If you want to do the "latest" gimick use nitrogen to fill your tires and the pressure won't ever change and there is no water in the "air" like there normally is. Of course you have to have ready access to more nitrogen or you're back to air again.

Probably more than you wanted to know:shock: Info that is forever stuck in my brain I guess.