what is the ideal tires pressure for CBR 900?

 

there isn't any. it will depend on riding style, riding type and type of tire.
even if you go with what the manual says, it may not jive with what the tire manufacturer says.

 

I run 36 in the front and 42 in the rear

 

.+1 on what tahoe said... start with the mfg recommendations and experiment.

In the wintertime, I go down a couple pounds.

 

well i was running 42 in rear and 36 in front but found that to be very bumpy. so i have gone down to 30 in rear and and 28 in front. u guys think thats ok? i find it comfortable but am worried about leaning on bends...

 

running 30 and 28 may wear tires faster... but as far as handling see how it feels gradually leaning over/turning a little more at a time. it's really as stated whatever you feel comfortable with.

 

What Tahoe said. If you're running the same tires as the bike came with, the manual and tire specs will match.
And as others mentioned, you can change tire pressure to fit/work around your riding style.

 

thanks guys... i am comfortable with 30 and 28 at the moment. much better than 42 and 36. but will try to slowly increase and see how the bike responds...

 

30-28 will make the tires run hotter, faster and thus wear out faster. At the track I run 32F30R on my Dunlops and 31F30R on the Diablo Corsas. They work VERY nice that way........but that is at track pace, far faster than a street pace. For the street on the same tires I run 36-36.

 

On my 99 with qualifier's, I run 34 front and 38 rear. I also have the bike set up for me as far as rider, so really depends on how your bike reacts to the pressure changes.......you'll definitely have to experiment with your tires to find the right pressure set up. Just remember that every bike is different.