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Discussion Starter #1
I forgot. But I presume mine is incorrrect!
 

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turbocohen said:
In warm weather I use 38 fr, 42 rear. In cool weather I raise a few pounds.
TC,
I don't think you actually meant to say you raise your tire pressure in cool WX...........
 

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Check under your seat...my 04 GT says 36 for the front and 42 for the rear...no offense, but it sounds like you don't check your pressure often. Make it habit.
 

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I think he did mean to say you raise tire pressure in cool wx..

In extremely hot weather/conditions, as for a track day, you would decrease the amount of pressure, in cold conditions you would compensate by increasing the pressure.

The book sez front-36.3 lbs. and rear- 42 lbs. for all load conditions. I increase the front to 40 to help prevent cupping on the GT.
 

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Generally, tires run cooler with higher pressure. They don't get as hot from the tire flexing. On the track, you lower the tire pressure so the tires warm up faster, and warmer they tend to be stickier. They also wear out faster, too. But, traction is more important on the track than longevity.
In the rain, you increase the tire pressure to prevent hydroplaning...which is usually when you have cool wx as well, so 6 of one, ½ dozen of the other.



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one more trick

all rider conditions are different, and manufacturers give underinflation numbers for the lawyers. my dealer says run 40/45. also, one wrench says inflate, check cold and hot, difference should be 10%. inflate accordingly. makes sense.
 

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Razel said:
In the rain, you increase the tire pressure to prevent hydroplaning...
Ray, I have to disagree with that. I believe that you should lower tire pressure in wet conditions for more traction. The design of tire tread pattern will prevent hydroplaning.
 

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Rickd, I respectfully disagree with your claim. Lower tire pressure offers less unit pressure contact with the road due to increased surface contact patch area. The tread does pump some water but weight per unit area keeps the rubber on the road. Lowered pressure is dangerous in rain, tag along with a crash forensics unit.. Among the first things they record is tire type, condition, pressure and skid mark width (if any).

As for cold temps, I raise a few pounds since my warm target pressure is the same year round which is about 42-43 fully warm front and 47-48 rear. After experimenting I found that adding about 2 pounds when temps drop under 45F results in about the right pressure. In cold weather there is more delta T i.e., tire pressure rise is less than in warm weather.

As mentioned earlier by another member, the tire pressure label is there to placate lawyers. Ideal tire pressure varies with use and temperature and the label is a safe one size fits all general use thang. Track pressures are much lower due to differing friction and compliance requirements along with significantly higher temps due to both low cold pressure and more knee dragging in corners. Naw, aint used pucks before on the K like the mad Dane.
 

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Under Pressure

Rick may have confused the addage, decrease pressure in sand, snow, or mud. But for rain, NEVER decrease pressure. The bigger footprint of the tire means more water has to be moved, and the lower force of the tire allows the water to push the tire inwards rather than evacuate the water.

some light reading:
http://www.thedrivingcompany.com/Safety.htm

http://www.tirerack.com/tires/tiretech/techpage.jsp?techid=3

and trivia:
The ONLY reason tires have grooves is to channel water away in the rain.

As for my personal favorite rain tire - hands down its Pilot Roads. We've scrapped the pegs two-up with the Roads in the rain. YMMV, PDCC, DNTTAH. ;)
 

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I am not trying to open a can of worms, but does any anyone have references to some actual testing (besides your own) of various pressure and it's effects on tirewear, grip, ect? I understand different conditions/use = different pressures, but there seems to be a trend here that few people have commented that they run the manufacturer recommended pressures.

Doh...guess I should have wait 4 more minutes for CABNFVR post...thanks :)
 

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turbocohen said:
Rickd, I respectfully disagree with your claim. Lower tire pressure offers less unit pressure contact with the road due to increased surface contact patch area.
My logic about lowering tire pressure when riding in the rain apparently is "all wet!" First of all, let me say I was... WRONG. Now it wasn't just because of Mr. James "turbo" Cohen's post that I came to this conclusion, although if he posts something of a technical nature, you will do well to heed what he says. He's right about 100% of the time. No, being hard headed and stubborn, I had to search out the truth on the internet. Lo and behold I found out what James told me to be correct. Surprise, surprise. Yes, I now agree, raise your tire pressures in the wet. I read that a 10% increase would be appropriate. What do you think James. Does that sound correct?

Although I have never changed tire pressures according to conditions, I do check them every time prior to a ride, unless I forget. :D

Razel said:
In the rain, you increase the tire pressure to prevent hydroplaning...
rickd said:
Ray, I have to disagree with that.
Sorry Ray, my bad.
 

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40 squared

This topic has been BEAT to death numerous times....

40/40 has been the all around consensus and I have been using this formula for the better part of the bike/tires life. Works well for me, maybe not for others?

And MSHEA......With all your add-ons, you may want to try 90/90;-)
 

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Discussion Starter #20
Which air pump do you use?

Thanks guys - obvoiusly, I DON'T check the pressure enough. I've not had the need this year because, frankly, she's not been ridden in a while. Not even the dealer uses the pressures recommended in the manual.

So which air pump do you use?
 
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