i have a 2001 sportsman 500 h.o.want to change rear tire size. to 25-11-12 would like to put them on 12x8 rims with 3x5 offsets to keep them under machine. dont no if this will work. any sugestions, options greatly appreciated

 

It should have 12x7 wheels with a 4+3 offset on the front and back, but if you want to go with 12x8 rims, a 3+5 offset would stick out 2" farther. It would make your ATV 4" wider but it would work.

 

Uh, that machine has 10" rims on the rear and a 4x4 bolt pattern for the studs! (25x11-10)
You would have to change the wheel hubs in order to use 12" tires and wheels regardless of the offset. IIRC, some guys install something like 03 Predator rims to accomplish that. There may be other hubs that will work but there's WAY more to it than just changing the rims.

 

I've been looking at various years and models of Sportsman ATVs online and so far all I've seen from 335-1000cc, including the diesel they used to make, is listed as a 4/156 pattern on the rear just like the front wheels, except the old chain-drive 2-stroke 400s that were a 4/4 pattern. I actually swapped my wheels front to back on my 1997 Sportsman 500 that had 10" rear wheels like his 2001, just to see if it could be done, and went for a ride down the street that way. My 2001 Sportsman 500 H.O. that was just like his also had the same bolt pattern on the front and back.

ETA: I saw another site that said my '97 Sportsman 500 and '01 500 H.O. were both a 4/4 bolt pattern on the rear but I know from my own experience they're wrong. The easiest way for rich274 to know for sure if the bolt patterns were the same on the front and rear would be to jack up one side of the ATV and see if the wheels will fit in the wrong positions.

 

If that's the case then I stand corrected. I thought those older models with the 10" rims on the rear also had 4/4 studs.

 

I'm not 100% sure but I think all the chain drive Polaris models, Trailblazer, Scrambler, Magnum, whatever, had 4/4 hubs in the back. All I know is it was a different hub with big fat lug nuts on the back of my Trailblazer 250. All my Sportsman 500s had small lug nuts just like the front of the Trailblazer. They're interchangeable front and rear and I'm glad they are. When a front wheel came loose on my '97 500 I took 1 lug nut from the other 3 wheels and put them on where the lugs were ruined from the wheel flopping around every time I turned. After I got home and put new lugs on it I bought 4 Whiz nuts from a hardware store instead of paying big bucks for the Polaris lug nuts. They were the same exact size but the flange was serrated instead of smooth.

After I thought about awhile I'm not sure I actually rode it with the wheels switched around, but I did swap them to the wrong end of the ATV to see how it looked. I definitely swapped the front wheels side to side so they were on backward and rode it around the corner and down the street. The wide stance may have been okay in some situations but the valve stems were hitting something. I can't remember what, but it was going click click click and wore a mark in the valve stem caps. I saw a jeep at a 4x4 pull that looked like the front wheels were on backward because it was really wide in front. The back tires weren't in the same tracks and maybe he thought that would give him better traction on the rear. All I know was it looked funny and my ATV did too when when I did the same thing to it.