Recommended Trailer Wheel Size for Carrying 88-lb Kayak and Other Items Totalling 300-lbs or Less

Question:

I am looking for a trailer to tow my kayak. Most of the trailers I have been looking at have 8inch wheels. I am a travelling nurse so it will be pulled long distances at highway speeds. Since the kayak weighs 88lbs and the extras will keep the weight to well below 300lbs will the 8inch wheels be safe or should I be looking at 12wheels?

asked by: Jeff

Expert Reply:

Tire size in itself does not mean that a tire is unsuitable for use on your kayak trailer which you'll be pulling long distances at highways speeds. Trailer tires are all rated for a maximum speed of 65-mph unless specified otherwise by their manufacturer, but they can vary significantly in how much of a weight load they can carry. Trailer tire load ranges are referred to by a letter code. Load range D tires can carry more weight than C tires, which in turn can carry more weight than Load range B tires.

For instance, a B-rated 8-inch bias ply tire like Kenda # AM10002 can carry 590-lbs at its rated pressure of 60-psi. Kenda load range C tire # AM10004 can handle up to 745-lbs at 90-psi inflation. And load range D tire # AM10013 can support 1075-lbs at its rated pressure of 100-psi.

The real threat to trailer tires is heat. If a tire is not inflated to its rated pressure (as noted on the tire sidewall) or if it is overloaded beyond its rated weight capacity then it will build up heat that will be the most likely reason for failure. A smaller tire that is properly inflated and operated within its specified load limits and up to its rated speed will serve you well. In general, if you use a tire rated for more weight than you're actually loading on it the tire will tend to run cooler and last longer.

If the nature of your trailer's design allows you to use larger diameter wheels and tires, then this is of course fine to do as well. You need to consider clearance at the fenders with a larger diameter tire, and clearance between the tires' inside walls and trailer frame for a wider tire. You also need new wheels (rims) that have the same bolt pattern as your current wheels so that they will fit your hubs.

I have linked several articles related to trailer tires that may be of interest to you. You may also want to consult the manufacturer of the trailer for their input about changing tire size.