18's front and rear. how wide?

[SliderNH]

Hey guys heres the setup: T500 with GT250 swingarm and front wheel, GT550 front end and shock works rear shocks. I'm looking to get the best handling I can. I'll be getting new aluminum wheels and I'm trying to figure out how wide to go. I was planning on running a 90/90/18 in the front and a 110/80/18 rear. Can anyone convince me that different size tire would be better? I measured my wheels - the rear looks like its 3.25 and the front looks like 2.5. I guess I was just going to stay with the same width rim for a lack of an better idea. Is this the best size to go with? I'm asking cause when I was browsing I saw someone with a 2.15 front and a 2.5 rear. I'd like to know why, and if that's a better set-up for handling. Thanks

[Zook-e]

18 x 2.15 front and 18 x 2.50 rear with those Avon tires. I am running those size wheels on my T250 Cafe bike.