Now that i've gone through this quad that I picked up I feel it needs some new tires. The fronts are 23x8x11 and the rears are 24x9x11. Are these machines gear differently in the front which would call for a smaller tire? Or can say 25" be put on front and rear. don't want the front and rear fighting each other.

 

I think on a 4 x 4 it's best to stay with what the OEM tires are. Especially if they are different sizes front & rear. If they were all 24's or 25' or 26's, then it wouldn't matter so much, as long as you always kept them the same size all around. In other words, if OEM were all 25's, and you put on all 26's, no problem. But being different sizes, there's no way that you can possibly get the same ratio with any sizes except the OEM. So, first thing is to look in the manual, or elsewhere to make sure the tires that are on it now are OEM sizes. Then go from there.

 

Yes, they are geared differently and that's why the popular opinion is that no matter how tall of a tire you put on them, you need to keep a one inch shorter tire on the front than the back.
However,...I know folks who have run the same sizes on the front and back ever since the 300 models came out and they get away with it by just running a little more air pressure in the rear than the front.

 

Thanks, I figured gearing was the case but it's always better to ask if your not 100% sure

 

Technically, just because 2 tires are 1" diameter different, doesn't mean they are the same difference around the circumference. It's the circumference ratio that matters, not the diameter ratio. A 22 & 23 have a circumference ratio of .956 but a 25 & 26 have a circumference ratio of .961. Does that little bit matter? Well, probably not, but it will stress the gears more than the correct ratio.