Tires rubbing trailer deck

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Bought a gooseneck trailer last year. My Dad has them put 14 ply tires on it in an attempt to combat my tendency to overload. 😆

Discovered last week that the tires are rubbing the wood deck when carrying a good load. Then realized that they'd put larger tires on the trailer than it needs. They're 235/85's. Unloaded I've maybe got 2 inches between tires and wood. Can't believe I have yet to smell it or see smoke.

Would I be better to get some smaller tires or is it possible to add a leaf to the spring pack on the trailer to lift it up a bit?

I'm hoping the dealer will fix the issue, as he shouldn't have put the tires on there if they were going to rub. But not gonna hold my breath as it's been 11 months. I should have caught it before now. That's my mistake.
 
Part of the issue is the 14 ply in addition to the larger size. The heavy ply tires sidewalls have a lot less flex than lower ply tires . So you get very little if any squat under heavy load.
My suggestion would be not overload the trailer. Any trailer modifications such as add leaf or modifications will only compound the added stress on the trailer
 
Loaded tires only squat on the bottom....

Trailer ply rating has nothing to do with it.

My gooseneck flatbed had that problem with going from 235/80 to a 235/85, so I removed the wood deck over the tires and went with diamond plate steel. Gives extra clearance.
You might want to brush up on your tire science. The difference between a 235/80r16 and a 235/85r16 is 5% of 235mm
235x..05 =11.75 mm
Or .46259843 of a inch
There is more variation in the height of a new tire and a bald exact same tire then 1/2 inch.
As far as side walls . The sidewall is the area of the tire that fails when it is overloaded /underinflated . To increase load carrying capacity you must strengthen the sidewall. Basic tire science.
Trailer tires are also more susceptible to lateral force damage than a tire on a drive axle. Thus the main difference between a trailer tire and a tire designed to be used on a power axle is where the extra reinforcement is in the tire. In a trailer tire extra reinforcement is placed along the tread/sidewall interface.
Wich additionally stiffens the side wall on top of any additional ply rating increase.
A tire designed for a power axle has additional reinforcement laterally along the tread to compensate for the torque of the power axle.
 
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A 235/85 is 1" taller overall so 1/2" closer to the trailer deck. On my trailer all I had was 1/2" between the 80 series tire and the underside of the deck at full compression, thus the 85s rubbed at full load. The diamond plate added plenty of extra clearance.

I understand all about tire sidewalls. But a loaded tire really only flexes on the bottom where it meets the road. If it's flexing on top then you have a compromised tire carcus and it's junk. So a 14ply tire will be no closer to rubbing the trailer deck than a softer 10ply.
 
If you are so certain that the material and training vehicle and tire manufacturers are wrong about higher ply is less side wall squish. Take you 1ton diesel pickup to the shop and have them install p rated tires on them . Then come back and tell me who is incorrect!
 
If you are so certain that the material and training vehicle and tire manufacturers are wrong about higher ply is less side wall squish. Take you 1ton diesel pickup to the shop and have them install p rated tires on them . Then come back and tell me who is incorrect!
A better test would be take that truck and put load range C tires with 10 psi in them and set a pallet of bricks in the back. Take a picture of that tire and tell us which side is flat.
 
Bought a gooseneck trailer last year. My Dad has them put 14 ply tires on it in an attempt to combat my tendency to overload. 😆

Discovered last week that the tires are rubbing the wood deck when carrying a good load. Then realized that they'd put larger tires on the trailer than it needs. They're 235/85's. Unloaded I've maybe got 2 inches between tires and wood. Can't believe I have yet to smell it or see smoke.

Would I be better to get some smaller tires or is it possible to add a leaf to the spring pack on the trailer to lift it up a bit?

I'm hoping the dealer will fix the issue, as he shouldn't have put the tires on there if they were going to rub. But not gonna hold my breath as it's been 11 months. I should have caught it before now. That's my mistake.
Could be tire size is just enough but like has been said that is pretty small difference. Probably just a poor design to begin with. Best way to fix it is diamond plate over the tires like most heavy duty trailers are made so they avoid that issue.
 
If you are so certain that the material and training vehicle and tire manufacturers are wrong about higher ply is less side wall squish. Take you 1ton diesel pickup to the shop and have them install p rated tires on them . Then come back and tell me who is incorrect!
Actually, he is.
 
If you are so certain that the material and training vehicle and tire manufacturers are wrong about higher ply is less side wall squish. Take you 1ton diesel pickup to the shop and have them install p rated tires on them . Then come back and tell me who is incorrect!

He is not arguing that they won't squat, but that the squat is only at the bottom. It would have no affect on the clearance between the top of the tire and the trailer deck, only the distance between the axle and road.

I would probably try to scoop 1/2" out of the trailer boards rather than try to add it to the trailer leafs.
 
I never said tires don't squat and that a stiffer sidewall doesn't reduce that. I'm saying a tire only squats when it meets the road (or rock or other solid object). No matter what load a tire has the distance from the center of the axle to the TOP of the tire doesn't really change, thus a higher ply tire has nothing to do with it rubbing the deck which is above the tire.
 
Bought a gooseneck trailer last year. My Dad has them put 14 ply tires on it in an attempt to combat my tendency to overload. 😆

Discovered last week that the tires are rubbing the wood deck when carrying a good load. Then realized that they'd put larger tires on the trailer than it needs. They're 235/85's. Unloaded I've maybe got 2 inches between tires and wood. Can't believe I have yet to smell it or see smoke.

Would I be better to get some smaller tires or is it possible to add a leaf to the spring pack on the trailer to lift it up a bit?

I'm hoping the dealer will fix the issue, as he shouldn't have put the tires on there if they were going to rub. But not gonna hold my breath as it's been 11 months. I should have caught it before now. That's my mistake.
I've had great experience with the little coil spring "helper springs" that you can bolt on between the axle and the frame. They install easily and they only engage when the weight is too much and the leaf springs sag.
 
Actually, he is.
...correct. Chevy is correct. I just noticed prior poster's verbege and didn't want my comment to be taken the wrong way.

The upper radius isn't going to appreciably change with load whether it's 10 ply or 14 ply.
 
These tires are larger than what it calls for. Not sure why. Different than what the trailers tag calls for.

I'm cutting the wood above the tires this week. Replacing with steel that sits above the wood. and getting some spring helpers.

Who tf sells a trailer where the tires are about to rub unloaded.
 
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