# tire size for 16' johnboat trailer



## pmshoemaker

Every evening I walk out and work on the trailer -- I look at those tires. They are small -- 4-lug, about 8" rims. Do I need to think about getting bigger tires? I'm replacing everything else, and I have no idea how old they are or how many hours they've been baked by the sun. Is there a rule of thumb for how big my trailer tires should be? I really don't see the boat approaching 1,000 lbs, but who knows once I start building. I will get better information on the tires/wheels when I get home and can see them. I just didn't know if there's a formula I don't know about.


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## Bateman

I pulled my first jon boat to work 25 miles nearly every day at 75mph on the interstate with the tiny wheelbarrow looking wheels and tires with zero problems. Previous owner towed it 7-8 hours to the beach with them. Trailer was from the 60's, but the tires were new/good condition and pressure was kept appropriate. 

If they are dry rotted or anything like that I wouldn't pull my boat with them personally.


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## New River Rat

I'm a firm believer in 5 lugs and 13" wheels, minimum. Tires and bearings wear less than 8" due to larger circumference. And you can get 13" tires that are specifically made for trailers.


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## eshaw

I have a 20 foot pontoon. That trailer has a single axle with 8 inch tires. No problem to date. I also have a 16 foot flat bottom john boat, all welded and it has some weight to it. That trailer uses 13 inch tires, and they're trailer tires. I've spoke with multiple tire people and radials will work ok for the trailer also. I have thought about adding a second axle to the john trailer.


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## ProduceMan

I put these on my trailer. When I bought the boat previous owner had 255/75 15's on it! https://www.walmart.com/ip/2-Pack-Trailer-Wheel-Tire-425-ST175-80D13-175-80-D-13-LRC-5-Hole-White-Spoke/49508386


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## eshaw

ProduceMan said:


> I put these on my trailer. When I bought the boat previous owner had 255/75 15's on it! https://www.walmart.com/ip/2-Pack-Trailer-Wheel-Tire-425-ST175-80D13-175-80-D-13-LRC-5-Hole-White-Spoke/49508386



Those are what's on my trailer for the jon boat.


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## thedude

Would be worth changing out the hubs to a five lug if you plan to haul any distance. Put some 175 80 13s on it. About $100 for a pair as some have posted.


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## pmshoemaker

Thanks guys -- it looks like my 4-lug configuration is going to limit me as far as tire options, so I'm leaning toward upgrading to 5-stud hubs. Is there any magic to replacing the hubs? it looks like a pretty simple, straightforward job. My springs look to be in good shape, and the axle is just a bar to hook the hubs to, right? As long as the ends are good, there's no real reason to replace that, is there? I'd rather not invest another $200 beyond the wheels and hubs.

Thanks


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## lckstckn2smknbrls

Bigger tires means you will have to back in farther to launch and retrieve your boat. You can go with 570x8, 480x12 or 530x12 tires of the proper weight rating.
One of my trailers has 4 lug bolt hubs, 3/4" bearings, 480x8 wheels and load range b tires. This trailer has been all over Illinois, Wisconsin, Iowa and Minnesota without any issues. Although I am putting a new axle on it with 1" or 1-1/16" bearings just because bearings and hubs are easier to come by.


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## GYPSY400

pmshoemaker said:


> Every evening I walk out and work on the trailer -- I look at those tires. They are small -- 4-lug, about 8" rims. Do I need to think about getting bigger tires? I'm replacing everything else, and I have no idea how old they are or how many hours they've been baked by the sun. Is there a rule of thumb for how big my trailer tires should be? I really don't see the boat approaching 1,000 lbs, but who knows once I start building. I will get better information on the tires/wheels when I get home and can see them. I just didn't know if there's a formula I don't know about.


It really depends on the ride height of the trailer compared to the tow vehicle.. if the tires make the trailer sit low because the truck is high, then sure upgrade to 4.80-12 Or 5.30-12. Ideal is having the trailer level as possible. 
The other benefit of a bigger tire is that they spin slower on the highway so it saves wear on the bearings ( less heat).. if you plan on long highway trips, ( 2+hrs) this is something to consider
You don't need a 5 bolt hub with only 1000lb trailer, 4 bolt ( torqued properly) will be fine, and probably cheaper. Check the weight rating of the Tire compared to what the trailer weighs. Some of the highest weight rated tires are 5.70-8.

DO NOT use Car tires on a trailer!! Trailer tires are Trailer tires for a reason.... they have a stiffer sidewall to add stability in corners.

Sent from my SM-G903W using Tapatalk


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## pmshoemaker

great insight -- thanks Gypsy 400


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## pmshoemaker

I just double checked and the trailer has 5.70-8's on it right now.


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## JL8Jeff

I prefer 12-14" wheels over the 8" wheels/tires. But the way trailer tires tend to dry out and crack, the size probably isn't as important as keeping an eye on them to know when to replace them. The last flat I had on my Jersey Speed Skiff wasn't even the tire, the rim developed a hairline crack.


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## eshaw

I'm running 14" tires on my trailer. It carries a 16 foot jon boat that weighs 1440 lbs. and the trailer is another 600. I run the 12 inch on the small 14x36 jon and trailer but that's a really light trailer/boat combo.


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## WV1951

Yea, you are limited with the 4 lug hubs. I am in the same situation and have looked into this. Another limiting factor is fender allowance. I have looked into 10" to replace my 8's, but as others have said here, with proper inflation, adequate condition, and sensible driving, the 8's should give you good service.


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## lugoismad

I have K550 tires, 13" wheels, 5 lug. Very nice compared to my old trailer with much smaller tires.


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## bcbouy

my old 12" tire rims said right on them do not exceed 55 mph.i swapped them out asap.70 mph plus on an 8" rim?crazy.if a bigger rim means deeper launching then just lower the bunks.


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## sportsman

Being a retired truck driver, I immediately replaced the 5.70x8 tires and wheels with 175x80x13 tires and wheels. While at it, because the newer wheels did not fit the old hubs, I built a new axle using 2500 lb spindles and 2 1/2 inch heavy wall square tubing, and Bearing Buddies. Yeah this is overkill, but I don't have to worry about burning up bearings now. When I took the bearings off the spindles, I found the old bearings had galled the spindles. Another reason to replace. Bought the spindle kits on line for less than $100 per pair. Cost less than $175.00 to build a complete new axle. My buddy welded the spindles with an inexpensive 110v wire feed welder. Also bought new fenders, but thats another story.


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## mr coastie

Greetings to all fellow boaters,
I have read several comments in regard to the tire "size" and load range capabilities.
weight is a contributing factor for tire selection too.
Please take into consideration "clearances" that will have you sitting at the side of the road if not proper.
I refer to the clearance between the rim and the tire to the inside of the fender, plus the spring hangers and the springs as well.
Is the fender large enough to allow the additional height of "bigger" tires?
is the offset of the wheel going to move the wheel edge and tire closer to object on the trailer that will hit them?
The clearances you have when the trailer is "unloaded" will reduce when "loaded" in most cases!
The changing from a 4.80X12-5 lug to a 13 inch wheel and tire assembly on my smaller trailer has enlightened me to ALL these issues. without and axle change out I remain with the 4.80X12...but 6 ply now!


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## el_cheapo

I have a 14' semi v that was on those little 8 inch tires and I blew out about 3 a season. Roads are shit in my area especially trying to get in the backwater/small lakes down gravel roads. There are pot holes more than 8 inches deep those little tires just couldn't take it especially not if you were trying to travel over 10 miles an hour. 

Ended up buying a junky old fiberglass boat, throwing it on the brush pile and keeping the motor and trailer. Trailer has 13 inch rims not sure tire diameter but it's close to my truck tires, and has a 3500 pound axle. Overkill for my little boat but now I can travel with the motor down and not worry about hitting anything, glide over pot holes reasonably easily (still gotta go easy on some) and haven't had a blow out since.

Life is much easier. Also once i do end up changing these tires I should be able to without the 4 way hitting the ground every rotation.


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## Justaguy442

I had 12's x 4 bolt on my 14' tin and i upgraded to 13 x 5 bolt. Alot bigger and wider which i believe will work better on gravel roads. 


I dont buy the car tire excuse on light boats. If they are both radial tires then the side walls are thin on both, unlike a bias. On heavier boats id say go with trailer tires for sure. But on a 1000 lbs boat i doubt youd notice a difference.


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## Justaguy442

So i was doing some research into the car tire vs Trailer Tire and they talked about trailer sway. My nephew has a 14' tin on a trailer with car tires and my brother mentioned it sways but they figure its because the tongue is longer then usual. So after reading this i will change my opinion and say that just use trailer tires. A swaying boat is not fun at 60 mph.


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