After recently upgrading my wheels on my 06 SG , I realize that I should probably ask around to see what the proper air pressure I should be running would be..

Rims are billet, tires are Avon, pretty much stock 06 SG, Im 190lbs..

running front 120/70-21 avon cobra
rear 150/70-18 avon roadraider

Any suggestions?

 

Ill stick to 40/40 thanks...

 

That's guessing! When changing brand, whether to stock or custom sizes, it is wise to check the manufacturer's website, from which we can see that a good starting point would be around 40F/44R. It's well worth doing a little experimentation around those numbers. My own experience is to use slightly higher pressures rather than lower.