Changing tire size on Jon Boat trailer

[SC Surveyor]

Greetings to all. I'm restoring a 14' MonArk Jon boat and trailer that have been sitting for 10 years and have a question about tire sizes. Currently the trailer has 4.8 x 8" tires on 4 lug rims. Since I'm replacing them, should I increase tire size to a 4.8 x 12" on 4 lug rims? I can raise the fenders and bunks easy enough. Just wasn't sure if the larger tire would help with trailering at higher speeds or longer distances. The main lake I fish (Lake Murray) is only 20 minutes from home, but I'd like to pull to the coast occasionally if it's safe. Any advice would be appreciated.

 

[roscoe]

Re: Changing tire size on Jon Boat trailer

It really won't make a difference.
Sure the wheels will spin slower, but if your bearings are bad, they will fail with either size wheel.

Tens of thousands of trailers out there using 8" wheels.

The boat will sit 2" higher, will that be a launch/load issue for you?

 

[lncoop]

Re: Changing tire size on Jon Boat trailer

+1. Really no reason to change tire size unless you just want to. Those 4.8 by 8s have been used on john boat trailers for many moons.

 

[SC Surveyor]

Re: Changing tire size on Jon Boat trailer

Bearings and seals are brand new this month. I plan to add bearing buddies as well. I've always been hesitant to pull for long distances on those small tires. Just figured since I'm changing the tires I might consider a size up. I don't think launch/load will be any problem. I pulled it off the trailer myself and set it on sawhorses before starting on the transom. Thanks for the reminder though.

 

[robert graham]

Re: Changing tire size on Jon Boat trailer

Not much reason to go from an 8" to a 12" other than it'll look better, and it'll make you feel better with bigger wheels. Those little 8" wheels look like they're just spinning their little guts out at 75MPH on the interstate! Good Luck!

 

[lncoop]

Re: Changing tire size on Jon Boat trailer

Not much reason to go from an 8" to a 12" other than it'll look better, and it'll make you feel better with bigger wheels. Those little 8" wheels look like they're just spinning their little guts out at 75MPH on the interstate! Good Luck!

Which really makes the grease caps bounce high when they come off! Not that I'd know anything about that.:redface:

 

[Bamaman1]

Re: Changing tire size on Jon Boat trailer

You're smart to address your bearings and tires prior to going to the lake. (I speak from experience--in a bad way.)

As you're changing the tires anyway, I'd go with the 12" tires of good quality. I put 50,000 miles on 8" tires on a utility trailer, and I had numerous blow outs. The 8" tires just don't seem to have any guts--and I have no faith in them.

While you're getting your hands dirty--spend $35 for a water pump impeller and new lower unit oil on your outboard motor. I suggest doing this on every used boat purchased to have peace of mind.

 

[SC Surveyor]

Re: Changing tire size on Jon Boat trailer

THAT'S what I'm talking about! Those little tires don't look like they should be going that fast! Everything looked good inside the hubs when I changed the bearings and the spindle's are smooth. Don't care much about how it looks, but I'm all for feeling better. I have to get new tires and the Wallyworld 12" tire and rim wasn't drasticly more the just the new tire from a tire shop when they add mounting and taxes.

 

[robert graham]

Re: Changing tire size on Jon Boat trailer

Go with the 12" tires for sure!...you'll just feel a lot better about it!

 

[SC Surveyor]

Re: Changing tire size on Jon Boat trailer

Thanks for all the input folks. I'm not affraid to look for a second opinion about something when questioning my own decisions, but it's great getting so many responses from folks I consider experts. I've been reading threads under several catagories that touch on my small resto. project, and the information has been invaluable. Thanks to you all.

 

[Home Cookin']

Re: Changing tire size on Jon Boat trailer

the nice thing about higher tires is your boat rides higher off the highway; yo might even be able to trailer without tilting the motor. And with that boat, you can crank it on to the trailer without sinking the axle, so the extra height won't affect you at the ramp.

 

[Bob's Garage]

Re: Changing tire size on Jon Boat trailer

Since you are so concerned with the wear and safety aspect of the tires, why would you purchase your tires from the China Capital of the World? I know they are cheaper, but you get what you pay for.

I have purchased tires from them, and have regretted it every time. I now purchase from a local guy, and get great tires that last until I hit the next curb or pothole, or debris on the highway.

I guess you can tell I don't much like WM nor their business practices.

Soap Box closed.

 

[Fishing Dude too]

Re: Changing tire size on Jon Boat trailer

Had a old camper, 1960 model had 8 inch tires, went to Seatle o those 8 inch tires. Main thing is weight on the tires. Bearins will wear out about every 10,000 miles. You decide but I would stay with 8 inch tires. Unless you deside to pack it like you were going on around the world tour.

 

[H20Rat]

Re: Changing tire size on Jon Boat trailer

My double snowmobile trailer has 8"'s on it, and I put thousands of miles on that every winter without issue. Quality tires make a world of difference!

 

[etracer68]

Re: Changing tire size on Jon Boat trailer

I would go with the 12" tire of the best quality your wallet can handle. Also dont forget the third one for a spare. The 12" will be easier on the bearings. Once you put them on, go for a 20 to 30 min ride at high speed, and stop and feel the hubs for heat, you should be able to hold your hand on them (cool to slightly warm, but never hot).

 

[SC Surveyor]

Re: Changing tire size on Jon Boat trailer

More good advice to ponder. I'm not a big fan of WM either, just used that as a cost comparison for the tire sizes. After looking at the trailer store here on iboats, I'm considering a compromise and trying the 570 x 8 tires. When placed side by side, the 570 is taller AND wider, but not so tall that I'll need to start raising everything on the trailer. For all the years I've owned this boat (18), I was never happy with those small tires but didn't really think to upgrade. With age comes wisdom! Thanks again y'all.

 

[I Did It!!]

Re: Changing tire size on Jon Boat trailer

I'd go with the 12" tires...If you travel 6 ft...the 8"tires will rotate 3+/_ times, whereas the 12" ones will rotate only twice...Thats a 50% reduction in rotation!!! The larger tires will run cooler, as will the bearings.....
Most very old boat trailers came with 8" tires, but you rarely see any newer ones with less than the 12'S..Much safer too, regardless of quality!!

 

[jessper]

Re: Changing tire size on Jon Boat trailer

It you go with the 12" tires, you can still keep one of your old 8" tires as a spare. The boat will sit a bit lopsided, but they will get you home. It is a lot easier to store a smaller spare, and saves you a bit of money by not having to buy another 12" tire.