Determining if Larger Diameter Snowmobile Trailer Tires Can Be Installed

Question:

can i put on 12 inch wheels and tires on it ? if so what size tires ?or what do you reccommend ? thank you.

asked by: Kelly Z

Expert Reply:

The metric size equivalent of the 18.5 x 8.5 - 8 tire size on your snowmobile trailer is the ST215/60-8 size, such as # AM1HP28 which is a tire only and # AM3H325 which is this tire size mounted on a galvanized 8-inch wheel with a 5-on-4-1/2-inch bolt pattern.

You may be able to use larger wheels/tires on your trailer so long as you can match up the bolt pattern on your hubs and so long as you have enough clearance in the wheel wells to fit a larger tire. The overall diameter of your current tire size is about 18-1/2-inches. You'll want to measure the space available around the tire to see if a larger 12-inch wheel and tire will fit. You also need to account for the travel of the suspension; usually we recommend no less than 3-inches of clearance for the normal deflection of the axle when you go over bumps.

If your trailer does not have fenders or wheel wells (or any other structures) that would get in the way of the larger diameter tire then there is no reason you cannot go for a larger wheel/tire.

You'll need to match up the bolt pattern to ensure the new wheel will fit on your hubs; the linked articles will show you how to confirm which bolt pattern your wheels use and provide details about the dimensions of various tire sizes. You also want to make sure the wheel and tire have at least the same weight capacity rating as the original wheels/tires.

The linked page displays all 12-inch trailer wheels/tires that are offered already mounted together.
You can click on the filters on the page to select your bolt pattern, tire size, preferred tire type, as well as the tire Load Range.

For example, if you want a 5-on-4-1/2 bolt pattern 12-inch white wheel with a 4.80-12 bias ply tire in Load Range C you can use part # AM30660. This consists of a 12 x 4-inch wheel and a Load Range C tire that offers a load capacity of 990-lbs at 90-psi pressure. You can find your current tire load rating on its sidewall.