My dad has a Grizzly and will be in the market for some new tires here soon. I suggested the Titan 589's for him, he would like to go bigger than stock but keep the stock rims. I figure the 26x9x12 front, 26x12x12 rear combo would work for him? Will this set-up work on his bike, could he go with the 27" set-up? He doesn't want any rubbing. He don't have access to the net so I told him I would do some research for him. Thanks for your help folks.

I ordered the 26's you describe (AT589's because there are other variations out now) with douglas .190 wheels from rocky mountain ATV for $575 delivered and mounted and they don't rub at all on my 2000 Grizzly. They come in a little shorter than 26" so they are close to stock in height, but the 26X12 have a slightly deeper tread than even the 27" 589's and they even weight a little more and are slightly wider (not to mention $20 cheaper per tire) than the 27's so they are pretty similiar tires and I would imagine the clearance is fine with either. Although I haven't compared the stock wheels to the douglas wheels as far as width and offset and so-on.

They are a fantastic mud/snow/hard-pack tire and they look great too. He will definately notice the added weight though when riding. I like the idea of having the other tires on the stock wheels available to swap back and forth. either way, he will be happy with them!