# Trailer tires help!!!



## Rob Silver (Mar 26, 2014)

Hi,

There's a really good price for a 72" axle, that comes with 5 x 4.5 bolt hubs.....and I want to take advantage of it.....FREE shipping!!! bonus!

I do have 4 sets of tires/rims (195/65 R15) with the exact same bolt spec as those on the axle for sale.

My question: Are there any disadvantages of having 15 inchers on a boat trailer?
Should I go to a smaller diameter rim/tire set?
Are there any disadvantages?
I have no idea if going large on my trailer tires would have negative effects. Please educate me.

One really good advantage that I see is that I have 2 spares for both the trailer and my car!


I really would appreciate any advice the group can give me.

Thanks!


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## stevesecotec02 (Mar 26, 2014)

Only downside I can see is it will cause the boat to be higher up off the ground. Wont be a problem if where you launch is deep but if you launch at some shallow ramps in summer when water is down could be a pain.


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## Kismet (Mar 26, 2014)

I am reminded of a time, years ago, when I had the marvelous fortune to get a FREE trailer, home-made, with an auto axle and 15in tires on it.

With an 18hp johnson, 13ft tin, and comic results, the tires had more bouyancy than the craft had weight.

Sooooo...I backed into the lake, put the car in park, and watched the boat, motor, and trailer float happily about alongside the pier.

Although spectators enjoyed it, I do not recall it being my finest hour.


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## Rob Silver (Mar 27, 2014)

Cute story Kis.
Do you think that would happen to me as well?

I have a 16' mirrocraft with a 60hp Mariner at back.
Now I'm curious if this will happen to me as well. Aside from the possible floating of my trailer, anything else on the negative side? Any positive to having this set-up?
Would it tow better compared to having smaller diameter tires?



Steve, as usual, thanks for pointing that out. The ramps here in Ontario, at least the ones that I frequent, are pretty much in good all around condition. As to how deep during summer.....no idea. 
I can see how that would pose a problem....not only in releasing, but as well as in retrieving. 
What diameter tire would you recommend then?

Thanks in advance!


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## stevesecotec02 (Mar 27, 2014)

I would think a 13 would be plenty for your application. 13" trailer tires typically are 175/80/13. Rated for 1300lbs each so 2600lbs total. Whats your rig weigh?


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## Rob Silver (Mar 27, 2014)

Boat is about 300 inclusive of flooring I plan to put in.
With coolers and other picnic stuff, another 200?
Plus the motor at 200.

All told --- 700 lbs.

If I were to go 13" tires, that would cost me another $225 plus taxes.
If I was to use the 15's I have right now, my only cost is the axle and hubs....$125 delivered!

Give me sage advice!


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## earl60446 (Mar 27, 2014)

I would definitely try it with the 15 inchers. I think it will go just fine. Plus you can run a few less
pounds pressure to keep it from bouncing too much. Certainly never have to worry about wearing them out.
Tim


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## muskiemike12 (Mar 27, 2014)

I had a 1979 16' Mirrocraft with a 70 Johnson on it and I ran 12" rims. 5.30x12 if I recall. It towed just fine and even took it to Canada a couple of times.


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## Rob Silver (Mar 27, 2014)

Earl, I believe that I will take you up on your recommendation.
I read online that car tires are acceptable on a trailer, as long as you reduce the tire's rated weight by 10%.
Since my rig would top out at about 700-850 pounds, and my 15" tires are rated for 1300lbs each, I think I am in the clear.


Muskie....The 12 inchers that I have on right now are on a 4 bolt pattern. My 15"s have 5 bolts on them.....which is what is needed for the axle assembly that I am getting a deal on (way cheaper to buy the axle assembly than to buy 2 tires for the 12" rims). The 12s aren't suited for much more traveling on highways...thus the need to take advantage of what I currently have and afford. But thanks for letting me know that 12s can and will travel extended distances and be safe.

If the tires float the whole rig, or if they're too tall for the boat to release from the trailer, that's when I'll consider purchasing new tires/rims. 

Thanks for all the advice. Tinboats rock yo!


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## Boat2fast (Mar 30, 2014)

Everything is fine as long as everything is fine.

I think about what happens when the road turns rough. Big tires and wheels weigh a lot. They start jumping up and down over some good bumps; they can transfer a lot of energy to the trailer. It is called "unsprung weight". Weight above the spring is "sprung weight"

Too much spring can hurt a boat too. Too-heavy springs can't absorb shock, they just transfer it. There isn't enough weight to make them work. Everyone has towed their trailer empty. One little bump and the trailer is airborn, bouncing up and down in the mirror.

Mismatched components can overload the other components. Use good quality components when rebuilding a trailer but don't use oversized components.

It is the job of a trailer to keep the boat safe when it's not in the water. It should give the boat a nice ride and protect it from road-shock.

My 2c...


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## Clint KY (May 8, 2014)

Another consideration is hub speed. If you are going to tow long distances at highway speeds, the smaller the tire the faster the hub turns. The faster the hub turns the faster the bearings go away. My old Dilly trailer with 8" wheels would heat well greased hubs to finger blistering heat in less than 50 miles of 70 MPH. When I lived in New England a fellow with whom I fished made a trip up into Canada every year and before he left he changed the wheels on his trailer from 12" to 15" and carried the smaller ones with him to make the boat easier to launch on unimproved ramps. Then he changed them back for the trip home. 

I would stay with the 15" unless you have trouble launching at shallow ramps.


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