15 or 13 inch tires???

A

Andrew Holley

Well-known member
Boat trailer is coming together. Finailly got most of the parts and some of the steel. Me and Eric D. welded up the stringers?/sides going with a welded I beam design. 2 x 4 on the bottom, 1 x 1 raiser and a 2 x 2 on top, all eleven gauge. Bending in the modified pipe bender went really well, but with a 16 ton jack, about all I could get for a bend was thirty degrees, which was enough. Little more welding this weekend and next weekend I will be working on the cross members and front end.

But I have and question which I have been debating for some time and that is tire size. I am starting to get cheap, because I have a lot tied up in this project, 15 tires, with rims are $100, 13 inch tires are $70. My father keeps telling me to put the 15 on as it will save/help the bearings. Will it?

Hunt Dave and Steve, what are your thoughts?

If it matters, boat will weight about a 2,200 fully loaded and the trailer will have a total length pushing 30 feet.
 
Yes, I believe all that Pi stuff, but what does 15% mean to bearing life? What about the weight to tire size? Does that matter?
 
Higher speeds, less life. Higher loads, less life. What does that mean in your situtation, I don't know. You might not ever push the 13" wheels/bearings beyond their operating envelope. 8" wheels to 12" wheels is a big jump. Your's not so much.
 
Eric,

How appropriate. I'm about to divulge how big of a nerd I am!!

Today is national Pi day.
No Joke! (link)

Joe Lane
 
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With a boat pushing 30 feet how much confidence will the smaller tires inspire?

The last thing you need is to look at the setup and think "Man those tires are small." :^)

Then you are going to be out the $70.00 on top of the $100.00 you will spend on the bigger tires.


My .02
Eric
 
You have spent how much on this project? And now are going to get cheap on the tires? A $60 difference? You will spend more than that in gas on your first trip. Get the bigger tires and sleep better.
 
Do they make a heavy duty 13" tire? Can you get a 13" tire in every cheesehead town in Wisconson when you get a flat there? With that yaht, you should get some Hummer tires and wheels.
 
Yeh, your all probably right and I should go with the 15s, But my play money is all gone and with gas at $3.30 a gallon, the fund isn't getting replenished as quickly as it used to.

Andy, I haven't gone through my receipts in awhile, but probably around $6K so far, not including the motor. Between whats left to do with the trailer: more steel, tires, sandblast and paint, will probably be another grand. To finish out the boat, probably another grand there too. When I started my estimate was $10K without the motor.

The most of the ice is gone on the river and I have seen a few boat out trolling for eyes, so would really like to go float the boat and see where the water line and balance is, but don't think that is going to happen unit early May.

I past a year into this project last month.
 
Andrew

I just did a little checking and here is some info I came up with.

Shorelander uses a ST185/80R13-C tire on trailers up to 2200 carry capacity (2960 gross) They go to a ST215/75R14-C tire on trailers rated for 2300 carry cap.(2995 gross) and same tire on 3000 carry cap.(3740 gross)

It looks like a 14 inch tire would be a better choice over the 13 inch size as you would be at the upper end of the range for the 13 inch tire. Any special reason for jumping to a 15? Taller tires will put your boat further off the water when launching. Will the boat need to raised higher on the trailer to clear taller tires? If so this will again put it further from the water. Are you planing on using a trailer tire or an automotive tire? I ask because a true trailer tire is made for towing.

Here is a quote from a tire source;

[font=Arial, Arial, sans-serif][/font]
[font=Arial, Arial, sans-serif]TIRE SIZE[/font]
[font=Times New Roman, serif][font=Arial, Arial, sans-serif]To maintain the trailer’s carrying capacity and safety, purchase only the same size tires as what were originally supplied on the trailer. The tires on the trailer are an ST rated tire. This means that they are a Special Trailer service tire that has more load carrying capac­ity than a comparable size tire automotive grade tire. The carrying capacity molded on the side wall of an automotive tire must be reduced by 10% if it is going to be used on a trailer.[/font][/font]
Click to expand...


[font=Times New Roman, serif][font=Arial, Arial, sans-serif]I can't explain why this is true (the above quote) but I do believe it.
[/font][/font]


[font=Times New Roman, serif][font=Arial, Arial, sans-serif][/font][/font]Here is a link to shorelanders site, link select a weight range, then a specific trailer, then click on "specs" to get tire sizes for that trailer.
 
I wasn't asked but,

Go with the biggest tires you can get with clearance under your fenders. You can get 6 ply steel belted radials if you look around. Expensive but well worth it unless you like changing tires at night on the shoulder of a highway. That's what my Dad and experience have taught me. Also put "Bearing Buddies" on the hubs but don't over grease them. Wash your trailer after each use with copius amounts of fresh water. Unhook your lights before putting your trailer in the water (don't forget to rehook after loading) All of that and your trailer should last you longer than the boat.

Just my $.02 worth,

Harry

PS I understand about the 3.30 per gallon gas and being short of money, but don't short the trailer as you will pay again and again for it later. Been there done that.
 
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No offense meant Harry. Just that Dave and Steve always seem to know alot of trailer stuff.

I kind of knew in advance what everyone was going to say.

Dave, going to look around for 14", but don't think either Fleets or Menard carry them. Looked them up on Northern Tool and they were the same price as 15", which I can get locally and avoid shipping.

Thanks much guys for you opinions.

Andrew
 
No offense taken Andrew,
Just happens to be a subject (changing trailer tires and dealing with bum trailers) that I have way too much experience with. (over 20 different boats and trailers in the last 40 years. Yes that means I bought my first boat when I was 18. first boat was a 19' fiberform Inboard/outboard on a fleet cap'n trailer. They were both dogs meaning no offense to retreivers.)
Check with an auto tire dealer that usually gives you a good deal. The last tires I bought go on the trailer under my Grady White 21 footer were special ordered through such a dealer. I got 15 inch steel belted specialty trailer tires for way less than I could get them anywhere else, he spun balanced mounted and put on the tires for an extra $10 each. Each tire is rated at 1760 lbs of boat and trailer weight. Got 12" under my 14' aluma carft and 14" under my Boston Whaler 17' Montauk. It's an expensive subject an you get to buy tires for life.

Good luck,
Harry
 
You got any van conversion companies around? One near me used to sell brand new wheel/tire takeoffs for about 10 bucks apiece...that was a while ago so they may be 20 bucks each now. Get a stadard chevy or for bolt hole pattern on your spindle so wheels are easy.
 
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