I just took the stock 25" tires and rims off of my new Foreman and put on a set of ITP rims with a set of 27" 589's. Even though there is supposedly a 2" difference in the size of these tires, they are almost the same height side by side. The 589's are heavier though and wider. They seem to scrub off some top end speed but it has plenty of power to turn them. Does anybody have any long term experience with larger tires on a four wheeler either good or bad to share? Any experience or problems caused with the drive train ect.? What are some opinions - is the trade off worth it?

 

the heavier tires put more stress on the drivetrain, thats a given. if you have the money, you can minimize the strain on it by getting aluminum wheels. I suggest the C-Series

 

Its going to take more power to turn them over and your acceleration will decrease, but it shouldn't affect your top end that much. It will drop your speedometer reading though.

Think of it this way. Take a 25" tire, measure the circumferece of it (all the way around). Do the same for a 27" tire. Mark that on the ground and roll it over one full turn. It will take a longer distance for the 27" tire to make one revolution. Ok, granted that you axe (in the center of the wheel and tire) makes one full turn. The 27" tire will travel a farther distance than the 25" tire with a full turn.

Well, if the quad has the power to turn the axle at the same speed with a 27" tire as it does with a 25" tire, then you will actually be covering more ground in one revolution of the axle, and your top speed will actually be greater. Your speedometer will be slower though, because it is calibrated for the 25" tire.

and on a lighter note, most speedometers are optimistic as hell, so you will probably have a more accurate reading with a larger tire. Have to use a GPS or radar to really tell for sure though.