Just my $0.02 but I'd take it to a real tire store and have them replace the hubs and bearings as well as getting some new trailer tires.

Take it to a tire store.

Don’t necessarily need to replace bearings...but definitely pull and grease. If the tires are worn...odds are the previous owner doesn’t know you need to grease bearings.

---

----------------------------------------------------------------

My training

Trailer tires are different from passenger tires, generally more solid and higher pressure.. they perform different functions from a car tire, mostly around heat dispersion and trailer stability...

A good tire shop should be able to hook you up. As was mentioned, if the tires had time to rot, then bearings and hubs should be looked at, too...

If your bearings go out, you will wish it was something as simple as a flat tire.

I've rebuilt a few boat trailers over the past few years.

I do the work myself, but this site is really good. https://www.etrailer.com/

They are pretty helpful if you call also to answer questions. I find ordering tires from them (for trailers) is cheaper than any local store.

ETA: I should qualify that all my trailers have used 12" tires, so definitely not in the passenger car variety.


.

Trailer tires are meant to handle higher air pressures and have stiffer sidewalls because they are bias-ply, not radial-ply. Trailer tires heat up more than vehicle tires because they are smaller in diameter and thus rotate faster at the same speed. I'd recommend you get "real" trailer tires.

Also, in addition to getting your bearings looked at, and at a minimum repacked if not replaced, I'd also get your axles, springs, and coupler looked at. Failure of any one of those will definitely ruin your weekend, and possibly someone else's.

Last, and something most people don't do--put a tie-down chain on your bow eye to keep the boat on the trailer in case your pulley rope/strap fails.

We lost a tire on our pop-up on a Sunday in the middle of nowhere. We were able to replace with spare after pumping up spare with bike pump- but then we were left with two suspect tires half way between steamboat springs and vernal Utah on a Sunday.

It was fun. Luckily the trailer was not heavier as when it went it went with the tread separating and flying way up in the air. It was had to keep control of it.

Definitely get good tires for long distance hauling through desolate places.

Oh and check your spare- I bought a used horse trailer and could not get the spare tire to stay on the mount til I realized it was a different lug pattern than the actual tires (and I bought it from a mechanical engineer...). Spare tires does not really mean any spare tire you happen to have.

Now that made me laugh. And think of another issue. Lug wrench. My trailer has lug nuts that are a different size than my truck's. So I had to buy a lug wrench just for it.

Nosmo, and all who have responded...thanks.

The plan is definitely to get trailer tires, and have all the things people suggest looked at. I initially took in the rims to the biggest tire store in town, they just didn't have any trailer tires of my size in stock, and i was in a pinch to move the boat, so i opted for the passenger tires. But i have a houseboat trip in a week, and want to take the new little boat with us, so I am contemplating driving out to Arizona on the passenger tires. I will order the trailer tires, but for this trip, I was looking for some level of comfort with any ST advice. So if yooze all with experience thinks that's a bad idea, I'm all ears.

I would NOT drive a long distance with passenger tires on a trailer, unless the tires are LT rated, which I am guessing the ones you bought are not. Especially you mention driving in AZ. That makes me think it will be HOT. As others mentioned trailer tires have stiffer sidewalls and other build aspects that make them the only choice. The wrong tire with a flexible sidewall generates a LOT of heat, plus a high ambient temp and high asphalt temp would scare the crap out of me at highway speeds. The Firestone/Explorer roll overs were caused from low air pressure, and the resultant heat.

Being ST think of it as using a road bike tire on a mountain bike. May work some of the time and can likely get away with it for a certain time, but do you want to be on that saddle when the shit hits the fan????

I wouldn't trust them myself, given that a failure could be fatal. As others mentioned too the bearings, chains, coupler, and if there are brakes (surge or electric) all those should be checked over prior to any longer trips if you aren't familiar with the trailer.

Here is a Tire Rack website discussing tires for trailers vs. cars:

https://www.tirerack.com/...hpage.jsp?techid=219

All the best.

What is the load range/rating on the tires on the trailer now? Weight of the boat/trailer? I towed a 5000lb popup using truck tires for years without a problem, but the tires were rated to handle the load.

If you are boating out of Temple Bar or other end-of-the-earth marinas, the last thing you want is to be stuck with a breakdown 50 miles from nowhere in 100+ degree heat.

---

____________
"There are two novels that can change a bookish fourteen-year old's life: The Lord of the Rings and Atlas Shrugged. One is a childish fantasy that often engenders a lifelong obsession with its unbelievable heroes, leading to an emotionally stunted, socially crippled adulthood, unable to deal with the real world. The other, of course, involves orcs." John Rogers

19' Bayliner isn't a heavy boat, could get away with a car tire likely, definitely service the hubs before any high speed or long distances

Did I miss it? Is this a single or dual axle trailer?

What is the load capacity of the tires (that you just bought). Compared to the gross trailer weight?

Single axle.
Current brand new passenger tires are rated 91H (whatever that means)
This boat and trailer just dropped into my lap, so I really don't know anything about the gross trailer weight. But I wouldn't think a 19' fiberglass boat and trailer would be that heavy?

I am going to listen to Jimmyn, and replace them ASAP.

Only going from San Pedro to Lake Movahe (just north of Bullhead City if your'e not from the area.) I take hwy 40 east, and there's a 140 mile stretch of nuthing but scrub brush., so I am not going to gamble. I'll buy trailer tires, and eat the cost of the passenger tires for a little security.

The current setup would have been fine to occasionally launch at Cabrillo Beach near my home, but going across the desert in June now makes me think twice.

This would only be an issue if the rims were small trailer rims (like for 12" trailer tires). He hasn't really clarified the actual size of the wheels he has. My assumption at this point if he got passenger tires, then they were put onto passenger car sized rims...which means no extra "heat" generated. So if the rims/wheels are passenger car size, I see no issues with just using the passenger tires he already bought.

.

 
I have a 19' Maxum runabout with the 5.0 V8 engine and it weighs in dry at 2,860lbs according to a spec sheet I found online. So figure 3k-3,200 loaded with fluids and gear, add the trailer at 800lbs or so and I figure my setup weighs around 4klbs. According to the Tirerack article posted above it would be too heavy for passenger tires but under the limit for trailer tires.

Your trailer wheels aren't likely to be dinky little utility trailer wheels so heat build up from rotation is likely not an issue. The heat buildup you might experience would be from sidewall flex due to the trailer not having suspension other than the bounce of the axle.

I doubt it would sway much on those passenger tires, but it might a little if given the right speed and wind conditions. If your tow vehicle is on it's tow limit and the trailer starts swaying, you are gonna have a bad time.

I tow with a 3/4 diesel truck rated for close to 15klbs towing capacity so I don't even notice my boat back there. I imagine it could be done on the passenger car tires and likely be just fine. But like others said, once problem out in the middle of nowhere is going to ruin your day and maybe weekend.

Load range 91h means that the max weight carrying capacity is about 1300#s. Or 2,600#s total. If that boat trailer motor and stuff weighs anything close to that, then you have a problem.

Current set up
195 / 65R15
Tow rig Ford Expedition

Your local Costco should carry trailer tires, and will install them. Make sure you have a decent jack, and the correct lug wrench. The 40 is a long, slow tow. There will be no shortage of boats being towed either direction so you won't be alone for long if you have an issue.

You've gotten good advice. In a situation like this, I always ask myself what it would cost me if there is a failure. Spending $200 for two trailer tires (assuming it is a single axle trailer) is a small price to pay to avoid having to leave your boat on the side of the road and find a replacement tire on the way there, or even worse on the way home.

Go to Costco or even Walmart and buy two new trailer tires. Keep the ones you just put on as spares. Definitely make sure you have someone check the bearings.

I will echo some of the above comments- go ahead and get the trailer tires. In general, you can buy a basic trailer wheel/tire combo for around $30-40 at walmart or online, might be easier than switching the tire on your existing rim.

Also, I just renewed my BoatUS boat towing ( on the water) membership, and the 'trailer assist' add-on ( they will come out and fix it or tow the whole thing-trailer and boat) was only $14 additional per year. If you are not tending to the tires/wheels now, I would at least put that on there.

Have fun with the boat!

That's really good advice. I recently bought my first offshore boat and the first thing I did was buy BoatUS insurance. I typically don't pull it more than 10 miles and take care of my bearings, but you are right - $14 is a small price to pay for the coverage.