Radial tires on a boat trailer?

W_Guy

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I apologize if this subject has been discussed before but I was wondering if radial tires on a trailer wouldn't be a bad idea. I'm thinking about cornering and uneven road surfaces such as ruts that seem to toss around bias tires. Seems to me they would offer a much more steady ride and not tend to throw the trailer around.
Opinions??
 

onthelake2010

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Re: Radial tires on a boat trailer?

I apologize if this subject has been discussed before but I was wondering if radial tires on a trailer wouldn't be a bad idea. I'm thinking about cornering and uneven road surfaces such as ruts that seem to toss around bias tires. Seems to me they would offer a much more steady ride and not tend to throw the trailer around.
Opinions??

I have ST radials on our larger trailers.
The fishing boat still has bias tires, but they are only carrying 1200#
 
Last edited:

cpubud

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Re: Radial tires on a boat trailer?

I believe most trailers now a days come with radial tires .
 

H20Rat

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Re: Radial tires on a boat trailer?

I believe most trailers now a days come with radial tires .

Not at most of the ones I've seen... Bias are still cheaper, and tires don't make a sale. There are lots of trailer tire sizes that are bias only, you can't by radials if you wanted.

To the OP... Radials can sometimes actually add a little side to side movement, but the reduction in rolling resistance as well as traction more than make up for it.
 

onthelake2010

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Re: Radial tires on a boat trailer?

A good question would be what size of load are you pulling?
 

W_Guy

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Re: Radial tires on a boat trailer?

One would be about 1200lbs and the other 2800lbs.
 

smokeonthewater

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Re: Radial tires on a boat trailer?

It does not make a huge difference.... generally radials ride a bit softer and resist sway but for the most part nobody really cares..... run em if you want but don't expect to be able to tell any difference at all from the driver's seat, except that your back may feel a little better because you are sitting on a slightly thinner wallet.
 

Home Cookin'

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Re: Radial tires on a boat trailer?

from what I gathered from previous discussions and expert-sounding opinions: if you get radial be sure they are made for trailers and fully inflated to recommended #. The issue is that trailers have a lot more side-to-side force than cars, and the typical car radial will roll over onto the sidewall, or worse, on turns, and will pick up more sway. I would like to think, though, that a radial trailer tire would be designed to cover this.
 

gus-gus

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Re: Radial tires on a boat trailer?

I have run both, radials and bias on many trailers. The largest issues to me seem to end up about how well they last. How well they react to those speed bumps in parking lots and lastly fuel mileage. Load rating is critical, but should be easy enough for anyone to figure out. I personally like radials more, but above a load rating that is cheaply available, the price of radials climbs dramatically. Then bias is a better deal in my opinion.
 

dockwrecker

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Re: Radial tires on a boat trailer?

Radials cost me a little more but my towing milage also went up about two miles per gallon and they've lasted longer. Me says cheaper overall.
 

H20Rat

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Re: Radial tires on a boat trailer?

The issue is that trailers have a lot more side-to-side force than cars, and the typical car radial will roll over onto the sidewall,


Trailers don't have more side force... A sporty little car riding on the same size tires as a trailer will generate MANY, MANY times more sideforce... (lots of youtube videos from cameras mounted on guys cars, its amazing how much a tire can deflect... A trailer would be upside long before this point. Fast forward to about a minute in on this video)

http://www.youtube.com/watch?v=ZZ1uCH9ay1k

Anyway, your point still remains true though. Car tires have sidewalls that can flex for comfort and to aid in traction. On a trailer, that flexing can tip you over or start the whole mess swaying.
 

Alwhite00

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Re: Radial tires on a boat trailer?

I'm running radials on a tandem trailer that is about 5,500 lbs and it handles great. Never had bias on it so i can not offer a comparison.

LK
 

dingbat

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Re: Radial tires on a boat trailer?

Tandem axle, Radial tires here. No 1930's technology, Fred Flintstone tires on my trailers.
 

W_Guy

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Re: Radial tires on a boat trailer?

I guess my comparison related to my experience with running correct original bias ply tires on collectable cars on today's roads. The ruts in the tire lanes make it very difficult to maintain a straight line. The bias tires always want to climb the edges of the ruts, thus the car is always wandering left to right and you're always correcting. I see no reason why bias tires on a trailer wouldn't do the same thing to the trailer. The end result is that the load on the trailer is constantly shifting from side to side (flat roads, no problem).
When I changed to radials on the old cars, they track true in a straight line and I'm not fighting the steering wheel for corrections all the time.
I'm not worried about flipping the trailer over.
 

daklander

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Re: Radial tires on a boat trailer?

Doesn't discuss bias tires necessarily, however I think this info might be helpful- I sure learned a few things....
http://www.tirerack.com/tires/tiretech/techpage.jsp?techid=219

That article is spot on, particularly the information regarding using P tires on a trailer. That is where many people get screwed up with radials on a trailer and have sway issues. The use of P tires will only work if they have a load rating well above the trailer GVW and are inflated to the max PSI rating.
The only other viable option is running LT tires and should work well since the load ratings and ply are comparable to an ST tire. If a load is extremely heavy an LT may even be a better choice since they are available in a 12 ply.

I personally run radials on everything I have that has a radial available in that particular size.
 

drrpm

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Re: Radial tires on a boat trailer?

Radial tires are a huge improvement for cars, but not that big a deal on a trailer. When I replaced my trailer tires last summer I went from bias to radial since that's what they had in stock and I can't say that I've noticed a difference. My boat/trailer combo is a 20 ft bowrider on a single axle trailer with a max combined weight of 5,000 lb. The tires are 225/75/16's.
 

Thalasso

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Re: Radial tires on a boat trailer?

That article is spot on, particularly the information regarding using P tires on a trailer. That is where many people get screwed up with radials on a trailer and have sway issues. The use of P tires will only work if they have a load rating well above the trailer GVW and are inflated to the max PSI rating.
The only other viable option is running LT tires and should work well since the load ratings and ply are comparable to an ST tire. If a load is extremely heavy an LT may even be a better choice since they are available in a 12 ply.

I personally run radials on everything I have that has a radial available in that particular size.

Remember, LT tire ratings have to be decreased by 10% if used for trailer hauling
 

dingbat

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Re: Radial tires on a boat trailer?

The use of P tires will only work if they have a load rating well above the trailer GVW and are inflated to the max PSI rating.
I'm guessing you read a different version of the artcle than I did. It mentions that P-series tires when used on a trailer are to be derated by 10%, not the "well above the trailer GVW " you state below.

If P-series tires are so bad, don't you think NTSB would recommend against the use of P-Series tires on a trailer if there was even a hint that P-tires caused roll over problems?

Subpart B - Federal Motor Vehicle Safety Standards

?571.110 Tire selection and rims and motor home/recreation vehicle trailer load carrying capacity information for motor vehicles with a GVWR of 4,536 kilograms (10,000 pounds) or less

Tire load limits for multipurpose passenger vehicles, trucks, buses, and trailers. S4.2.2.1 Except as provided in S4.2.2.2, the sum of the maximum load ratings of the tires fitted to an axle shall not be less than the GAWR of the axle system as specified on the vehicle's certification label required by 49 CFR part 567. If the certification label shows more than one GAWR for the axle system, the sum shall be not less than the GAWR corresponding to the size designation of the tires fitted to the axle. S4.2.2.2 When passenger car tires are installed on an MPV, truck, bus, or trailer, each tire's load rating is reduced by dividing it by 1.10 before determining, under S4.2.2.1, the sum of the maximum load ratings of the tires fitted to an axle. S4.2.2.3 (a) For vehicles, except trailers with no designated seating positions, equipped with passenger car tires, the vehicle normal load on the tire shall be no greater than 94 percent of the derated load rating at the vehicle manufacturer's recommended cold inflation pressure for that tire. (b) For vehicles, except trailers with no designated seating positions, equipped with LT tires, the vehicle normal load on the tire shall be no greater than 94 percent of the load rating at the vehicle manufacturer's recommended cold inflation pressure for that tire.
 

daklander

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Re: Radial tires on a boat trailer?

I'm guessing you read a different version of the artcle than I did. It mentions that P-series tires when used on a trailer are to be derated by 10%, not the "well above the trailer GVW " you state below.

If P-series tires are so bad, don't you think NTSB would recommend against the use of P-Series tires on a trailer if there was even a hint that P-tires caused roll over problems?

Subpart B - Federal Motor Vehicle Safety Standards

?571.110 Tire selection and rims and motor home/recreation vehicle trailer load carrying capacity information for motor vehicles with a GVWR of 4,536 kilograms (10,000 pounds) or less

Tire load limits for multipurpose passenger vehicles, trucks, buses, and trailers. S4.2.2.1 Except as provided in S4.2.2.2, the sum of the maximum load ratings of the tires fitted to an axle shall not be less than the GAWR of the axle system as specified on the vehicle's certification label required by 49 CFR part 567. If the certification label shows more than one GAWR for the axle system, the sum shall be not less than the GAWR corresponding to the size designation of the tires fitted to the axle. S4.2.2.2 When passenger car tires are installed on an MPV, truck, bus, or trailer, each tire's load rating is reduced by dividing it by 1.10 before determining, under S4.2.2.1, the sum of the maximum load ratings of the tires fitted to an axle. S4.2.2.3 (a) For vehicles, except trailers with no designated seating positions, equipped with passenger car tires, the vehicle normal load on the tire shall be no greater than 94 percent of the derated load rating at the vehicle manufacturer's recommended cold inflation pressure for that tire. (b) For vehicles, except trailers with no designated seating positions, equipped with LT tires, the vehicle normal load on the tire shall be no greater than 94 percent of the load rating at the vehicle manufacturer's recommended cold inflation pressure for that tire.

I don't know, to me 10% is a rather large number when it comes to trailers and, to be truely safe when using P tires the load rating on the tires should be even higher, which is often impossible in a given size.
Keep in mind the numbers posted in the FMVSS regs are minimum standards.

You may also run into insurance coverage issues running automotive tires on a trailer. In general if a particular trailer came stock with ST tires and you are running P-metric tires and have an accident that can be trailer related you are, more than likely, going to be stuck with the costs because you have modified the stock trailer safety configuration.

Personally I'd rather be safe than sorry and I pretty much go by what Carlisle says.

This "Trailer Tires 101" document is, to me, a better source than the FMVSS which, again, gives the legal minimum requirements.

One of the benefits of an ST tire when it comes to trailering is that it has about 10 percent more load capacity than an equivalent LT tire and nearly 40 percent more than a P tire when each is filled to its maximum psi rating.

For trailers, it is essential that you select the correct tires to match your application and capacity requirements. (ST) Special Trailer tires are normally more expensive than (P) Passenger car or (LT) Light Truck tires because they are built tougher with more material and more bruise resistant. This is necessary because most trailer suspension systems are stiffer and less sophisticated than automotive suspension systems.
Consequently the tires must be capable of withstanding more ABUSE. As always consult with a professional for your specific circumstance.
 
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