Crummy tires

[guy48065]

I just bought 2 Kawasaki Zxi1100 jet skis (96 & 97) on a 2-place trailer. It's winter so I don't have any questions yet about the skis. My only "experience" so far has been trailering them home, so I'll start there.
The ride home was a lot more bouncy & noisy than I'm used to when pulling a trailer. The tires are Carlisle Sport Trail 4.80-12, each end of the axle is attached to a single leaf that isn't compressed a bit by the 1200 pounds of Kawasaki weight + the trailer. "Suspension" doesn't seem to fit in this case.
I want to replace these tires of unknown age (couldn't find a date code or DOT stamp) with something that has softer sidewalls. Is that ok on a light trailer?

 

[roscoe]

There is a code date on those tires, but probably the old style.

"ST" or "special trailer" tires have stiffer sidewalls. That is where the get their load carrying capacity.

The only tires you will find with a soft sidewall will be radials, and they don't come in sizes that small.

Most small light load trailer have little give in the springs.
They won't compress with the normal load on them.
They will give when/if you hit something like a pothole or curb.
Just the way it is.

Only option that comes to mind is to change out the axle with a light weight rated torsion axle.
But I don't know if that is wise or affordable. You are looking at $400-$600 plus the wheels and tires.

 

[matt167]

4.80x 12 are available from Carlisle up to LRF IIRC, and I know they go down to LRC.. so that is 6 ply vs 12 ply. If you have F's or E's on it, it's probably going to bounce a bit You can tell by the max pressure as well. E is 80 PSI, F is 95 PSI D is 65 PSI and C is 50 PSI

 

[bigdee]

Roscoe is right about that size tire. You may be tempted to lower the air pressure in those tires...DON'T! Accept the bounce and rough ride,it won't hurt a thing as long as the jet skis are tied down securely. It kills me why some people are so concerned how a trailer rides. Choppy water and wakes are just as severe.

 

[guy48065]

Not worried much about that. I don't like the noise & jostling of the tow vehicle.
My other trailers are easy to forget they're back there.

Wondering if the wider wheels often seen on snowmobile trailers might ride smoother. Similar weight & trailer types.

 

[GA_Boater]

Check the tongue weight. Too little makes for a squirmy trailer, but too much takes weight off the axle. Weight is what makes springs work and that's why empty or light trailers ride like rocks.

Check the coupler and ball fit, too. A loose fit will make for a noisy tow.

 

[bigdee]

Check the coupler and ball fit, too. A loose fit will make for a noisy tow.

Especially true for uni-body vehicles.

 

[ahicks]

Not worried much about that. I don't like the noise & jostling of the tow vehicle.
My other trailers are easy to forget they're back there.

Wondering if the wider wheels often seen on snowmobile trailers might ride smoother. Similar weight & trailer types.

20.5x8.00x10 are my favorites, and are about the same diameter as the 12" tires. Many thousands of miles over many years with all sorts of loads, and never a failure. They seem to respond well to being inflated partially (pressure depending on the load they are carrying) where the 4.80 and 5.30x12 sizes don't like that.

For your application, the idea of running the C rated tires mentioned earlier isn't a bad plan either.

 

[Sprig]

1200 lbs plus trailer shouldn’t jostle your vehicle when towing. What vehicle are you towing with. If it’s a smaller light weight vehicle that may be part of the problem.
I also concur too light of tongue weight could also be part of the problem.

 

[guy48065]

It's definitely too light... Maybe 50 pounds. I'll adjust that as soon as I can. The axle position isn't adjustable but the winch risers are mounted on a moveable cross-beam so I should be able to skootch the skis forward a bit.
The old tires are LRC (990#).

There might be enough clearance to run the wide wheels. Both fenders are missing so maybe I can find some wide enough to cover 10" wide tires.

I'm only considering new tires & wheels because the originals are plain ugly. If I can improve the ride at the same time, great.
Once I make the 200 mile trip to deliver them to my cottage it's possible this trailer will never again see highway.

 

[GA_Boater]

Why bother putting new tires and wheels on and park the trailer at the cottage? Save the bucks for gas.

 

[guy48065]

Why bother putting new tires and wheels on and park the trailer at the cottage? Save the bucks for gas.

You've seen nice toys left on the side of the road. I don't want to be that guy. :facepalm:

 

[jbetzelb]

Spray a bunch of WD40 on the springs too. As noted above they dont move that much and a little rust can reduce the flex in the spring even more.

 

[GA_Boater]

Don't forget to service the wheel bearings.

 

[ahicks]

Don't forget to service the wheel bearings.

^^^X2!!^^^

 

[Leardriver]

The lousy quality of trailer tires is one of the shameful things about any trailer. There just aren't any home run quality tires available.
On my dirt bike trailer, I got rid of the 5.30 X 12 tires, rated for about 900-ish pounds max, bought some 195/70/14" silver modular rims for $30 bux each, and put some 14" car tires on it, rated for 2000 pounds each. You can buy them used for $10 each on CL, and find an emergency spare anywhere. Smooth ride, and might outlive me. I like using trailer tires for heavy towing right at the weight limits, but when your trailer weights 1/3 of the max capacity, you are plenty safe.

 

[guy48065]

I'd agree with "shameful".
I just don't understand why trailer tires are so stiff when car tires have same or more capacity and ride much better.
I have a landscape trailer that came with nice aluminum rims & radial ST trailer tires. Very smooth even empty.
I also have an aluminum flat-top trailer that the PO installed radial whitewalls on. Easy to forget I'm pulling it...totally silent. That trailer also needs new tires & I'm tempted to ignore "conventional wisdom" and stay with regular radials.

 

[bigdee]

I'd agree with "shameful".
I just don't understand why trailer tires are so stiff when car tires have same or more capacity and ride much better.
.

They are stiff to prevent dangerous trailer sway. Once a trailer starts to sway it sets into motion an oscillation that keeps increasing until it goes out of control.....very scary to anyone that has ever experienced it. A trailer does not have the same type suspension as a passenger vehicle so there is no logic to put car tires on a trailer. A trailer tire will actually carry higher loads than a car tire...the reason it is rated lower is to factor in the shock loads of a bouncy trailer. The main concern for trailer is safety and not ride softness.

 

[ahicks]

I think a lot of tire buying decisions should weigh heavily on what kind of load they're typically going to see. A utility trailer running around with half or less capacity, or a row boat on a trailer with a 9.9 on the back, would be in a totally different class as compared to a trailer rated at 2000lbs with a 1500lb boat on it. Point being, I think there's a lot of gray between the black and white when it comes to trailer tires....

 

[guy48065]

They are stiff to prevent dangerous trailer sway. Once a trailer starts to sway it sets into motion an oscillation that keeps increasing until it goes out of control...

I've read that but I can't quite wrap my mind around it.
In most things to dampen oscillation you need compliance. A swaying trailer isn't helped by riding on pizza cutters. I wouldn't be surprised if bouncing over every bump and expansion joint doesn't aggravate oscillation.

The OCD engineer in me seeks understanding...