AIR PRESSURE QUESTION NOT IN MANUAL.

[OB_valklex]

All my previous bikes were hondas, and they always had air pressures of 36/36 for rider less than 200 Lb, and 42/42 for any total weight higher than 200 Lb. (heavy rider or riding 2-up). The busa only specifies 42/42, and I always ride solo, and my weight is 155 Lb. The 42 obviously covers a fully loaded bike (391 Lbs of extra weight), and it feels extremely harsh. Since I am only 155, if I change to 36/36, am I sacrificing anything? I'm talking about tread life, grip in corners, and stability at high speed. Thanks for your advice.

 

[OB_MANO]

speed ratings maybe.I have seen, and had, high speed tire failure from under inflation.I will never go a pound under if I can help it!Especially high speed riding!Heat build up on street tires is a problem I think.I still can't believe how good these new tires are!!

 

[OB_Deadly Impact]

I had new D207's at high temperature (Mexico and Arizona deserts). I am 165lbs and at 42/42 the bike was unstable at speed.

At 160mph the front felt very light. I cault a very light side wind and the front just started sliding across the road.

Initially I dropped it to 38/42 and that helped a lot. I think I will go 38/38 which should increase wear but what the hell. Tyres are chear skin is painful.

 

[OB_valklex]

My point is that it's not the same riding with my 155 Lb than with 390 Lb. 42 psi is the maximum allowed pressure to withstand the maximum allowed weight stamped on the tires at sustained top speed rating. The busa is far from fully loading the tires with just the weight of the bike and mine, so full pressure only causes unnecessary harshness. The precise question is: how many psi less under those conditions? 36/36 definitely doesn't qualify as underinflation, but maybe 38/38 is optimal. I also live in a very hot city (100-102 lately), and it reaches 110 in July (the asphalt probably reaches 130). I even see this as a safety concern, since riding at 42/42 might be promoting a blowout due to excessive pressure build-up.
I hope to hear from more people. Thanks for the two responses above.

 

[OB_Kirk]

About 14.7psi at sea level. Oh, sorry. Guess I should read the question before I respond. Try the thread I started for more info.

 

[OB_blitzn]

like you say.....max infation for max weight......im 220lbs and keep the pressure at 38 for the hwy & 35 or 36 for the twisty bits,but try different pressures to see what you like.

 

[OB_Johnnycheese]

they were tire tested in Texas and twisty tested in the mountauns north east of
San Digeo

 

[OB_Cisco San Jose]

42/42psi by the book.

 

[OB_JokerJ]

My questions is, to add to Valklex's, is the optimum pressure the one you want and measure when the tire is cold or when the tire is warmed up? I like my pressure at no more than 38/38, because once the tire heat up it builds to around 40/42 depending on how cold the day is. I find it a bit dangerous to fill a tire to maximum pressure when it's cold.

 

[Guest]

The more a tire flexes the more heat builds up in it. (Cameron, Sportbike Performance Handbook). The lower the pressure the more flexing therefore I keep my tires hard. Suzi's recommendation is 42 COLD. They must assume some pressure growth for hot roads. They test these bikes in the California Desert somewhere.

For you, a light weight guy riding hot roads I would try measuring the pressures at cold and later after a fast ride on hot roads and see what your numbers are. That may give you some hints about what to set your specific tires at.

Let us know what you decide.

 

[OB_Hayawoody]

Valkex, My experience is three fold. 1)Different make tires require different pressures,2)How good a rider you are and how you ride(cruisin or rippin thru the twistes) is another factor. 3)What pressure do you feel the bike handles the best for you? I don't think there's only one pressure that's the one and only! Hope this helps...just play with it!