trailer tire max load

[bowrider98]

Does the geometry of a trailer shift a couple hundred of pounds of gross trailer and boat weight from a single axle (2 tires) to the trailer hitch via tongue weight? I pulled a real stupid move replacing 185/80R13 tires (max load 2,980#) with 175/80D13 tires (max load 2,740#). Nothing available locally and didn't want to wait for parcel delivery - pretty stupid. I lost about 240# gross trailer weight which equals a full tank of gas. The gas tank is about empty and I removed all other gear not bolted down. I was curious if the trailer hitch and the tongue weight were calculated in the tire max load. Has anyone ever weighed each tire separately to see if any weight is shifted forward?

 

[90stingray]

Re: trailer tire max load

Wouldn't the weight be shifted a little more aft... since the tires are a hair shorter? The weight for the tire is everything it can handle. So add the weight of your boat with fuelthe and trailer and gear... then divide by two. See if you fall within your load rating.

 

[bowrider98]

Re: trailer tire max load

Wouldn't the weight be shifted a little more aft... since the tires are a hair shorter? The weight for the tire is everything it can handle. So add the weight of your boat with fuelthe and trailer and gear... then divide by two. See if you fall within your load rating.

the shorelandr manual calls for 5 -7percent of gross weight to be on the tongue at the trailer hitch for tow stability during setup of the trailer for the specific boat - approximately 175 - 200 pounds..

 

[jeeperman]

Re: trailer tire max load

I was curious if the trailer hitch and the tongue weight were calculated in the tire max load. Has anyone ever weighed each tire separately to see if any weight is shifted forward?

Even tho some of the weight will be carried by the hitch, your tires should be sized to carry ALL of the weight.
Plus a sizeable safety margin. Not sure what is recommended but I would like to see 40-50% extra.

As long as the distance from centerline of axle to either end of load does not change, the load at either end will not change.

 

[The_Kid]

Re: trailer tire max load

The radius of your original tire was 12.3 inches. the new tires are 12 inches so your trailer height only dropped .3 of an inch which isn't enough to make much difference in tongue weight.

Based on the max load of the old tires I have to guess that you have a 2000# axle so you still have a safety margin of 740# providing the numbers you gave were the sum for both tires.

185/80R13 (max load 1490# X 2 = 2,980#)
175/80D13 (max load1370# X 2 = 2,740#)

 

[sw33ttooth]

Re: trailer tire max load

weigh the boat and trailer find a drive on scale if your trailer and boat wiegh in at less then 2,500 your good it its right at 2,500 you might want to get the step up, some times its worth a drive, you only need new tires every 5-10 years.

toung wieght only comes into play when you put stuff into the bow or stern or shift the boats postion forward or backwards on the trailer by simply raising or lowering the trailer your toung weight wont change, for example replacing those 13 inch tires with 10 inch tires you will have the same toung wieght.

my boat trailer has 4 tires x 2240max lbs = 8960 total trailer/boat wieght is about 6300 full gas tank so i have a safty margine of 2660 lbs the next step down which previous owner had on the trailer were 4 tires x 1750max lbs = 7000 the safty margine was 700 lbs i didnt feel these tires were that safe, they had a little squat in them.