Tire pressure specs?

mine says 26 and 28

but it depends on bike and weight.
inside the side cover it chould say.

how much do u weigh?

xj750j: f r
up to 198 26 28
198 to 507 28 33

is this is not your bike let me know!

 

I run 32 front, 34 rear.

There is alot of debate about tire preasure.

GROUP 1:
Run high preasure for increased tire life on the highway. This keeps your tires cooler so they won't wear as quickly

GROUP 2:
Run lower preasure - it makes the contact patch larger so you don't wear the center of your tire out.

GROUP 1:
But that will make your tires run hotter

GROUP 2:
Sure - but it has a larger contact patch so it wears more of the tire... and when the tempature goes up so does preasure - so if they did get really hot then they'd be the same preasure as your tires. Same preasure same wear.

GROUP 1:
Is preasure and tempature linearly proportional?

GROUP 2:
I get better tire wear when I run lower preasure - plus I stick to the road better.

GROUP 1:
I get better tire wear when I run higher preasure. I might let some preasure off to run in the twisties.

GROUP 3:
I just run them at 32-34 and it works. I don't know why you guys are fighting about this.

GROUP 1 and 2:
Shut up. We both think you are wrong.

GROUP 3:
What ever.

 

I wasn't trying to cause a fight with myself - but seriously - groups 1 and 2 are right... I just don't know who is more right.

I tend to side with group 2 - lower tire preasure.

I personally think road tempature has alot to do with it - if you're riding in the south the road is so hot it doesn't really matter what tire preasure you run... the surface is going to be hot enough to wear. You may as well spread the wear over a larger surface area.

Up north? With a frozen road surface I don't think you'll get much wear riding sensibly.

 

Sno- my XJ750 ('82) manuals both owner's and shop call for 28 and 32-
Bill in GA

 

Tire pressures are indicated on the sticker on the headstock, as well as recommended tire sizes.
My '82 750 Seca specs 28# cold front, and 40# cold rear.
It should be on your bike unless there has been a frame repaint.
If you have changed the tire sizes, you may need to adjust your pressures.

Nachoman

 

You should always run the pressures recommended by the manufacturer of the rim, reguardless of tire specifications. The pressure specs from the tire manufacturer are a guideline of minumum and maximum range that the tire will accept because the tire can be used on more than one application. Your rim specs should fall within the tire specs. The rim is designed to work within certain parameters (i.e. a pressure range or specification) and is designed to accept the tires that fit it's diameter. Changing tire size should not have any bearing on the requirements of the rim. Too much pressure can lead to excessive pressures building up inside the tire carcass and over-pressuring the rim material (remember, friction equals heat and pressure). While I'm not going to disagree with the dynamics Woot argued, the stresses on the rim have to be concidered. Over pressurization is not a desireable condition as you loose contact area (ie control surface). Under-pressure can lead to premature sidewall failure (just look at all the hubub surrounding the SUV/tire issues of the 90's). I tend to lean toward the lower pressure side as the air pressure inside the tire will increase with friction. If you have already over-pressurized, you run the risk of blowout (not a nice thing on two wheels, can be fatal). Getting back to the rim issue, running over pressurized for a period of time can cause weakening of the sidebead on the rim (although I have a difficult time with this looking at how beefy our XJ's tend to be, at least on the stock rim). I'll confess right now I can't remember who or when I was informed about the requirements of following the rim specs (which at the time had to do with a car rim), but it is a logical perspective given the various dynamics we face in dealing with the issue. Ok, my two cents.

 

Another blurb, Haynes manual says, refer to tire manufacturer specs and defer to them. I'm not in agreement but will conceed that they should be kept in mind when deciding.

 

i run about 35# front and back