I purchased a three year old Dutchmen, 25 foot, 5000 lb. dry weight TT. It was close to mint condition and showed little signs of use.I put 18,000 miles on it in 2 years and decided to change out the OEM tires, which were date coded seven years old.For a few bucks more I could replace the C rated 205's with D rated 205's, so I opted for the higher rating. With the higher load rating came higher tire pressure 65 psi vs. 50 psi. In the last year we have towed 10,000 miles and several items have loosened up. The front bed pulled loose from the wall, the bath room drawer bottoms have loosened and the bottom pantry shelf pulled loose from the wall and sagged.So the question is, "Are the higher pressure D rated tires transferring more stress and vibration to the TT body?"I would not think 28,000 miles in three years to be excessive.

for one thing you need to know that building a TT is not rocket science. it could just be that model TT as to why things have come apart. to me 28K miles is a lot of miles

Well, yeah the higher weight rating + more psi = harder ride. No question about it. Is it so hard that its knocking things loose? Sure.Did you get the new tires balanced? Highly recommended. Might also be an issue if you did not, the trailer might be shaking itself apart in addition to the harder ride doing the same thing. Get the tires balanced and lower the tire PSI to 50-55. The load rating at this pressure will very likely be the same as the C's.These load/inflation charts are not brand specific;http://www.goodyearrvtires.com/pdfs/rv_inflation.pdf

Tires are not mfd to be 'suspension components', the more they flex the hotter they will run, and then fail; ST tires should always be run at max pressure

I made the same tire swap. Installed stiffer springs too. Has never ridden better. No issues here.

28,000 miles. Maybe your springs are half shot and not working right.

Tire rateings and trailer bounce? | Good Sam Community

11 Replies

JIMNLIN
Explorer III
Jan 19, 2017
time2roll wrote:
"lite" or not if it came with 205-15-C it is all about the weight.

The 205-15" C load range @ 1820 lbs times 4 = 7280 lb capacity which is well above his 5000 lb trailer tire needs.
The op added 4 205-15 D 65 psi high pressure tires at 2150 lbs X 4 = 8600 lbs capacity.

Trailers work fine with a quality tire with 10-15 percent reserve capacity above the trailers gawr.

I see a similar issue on another rv website where a member added 17.5" H load range @ 6000 lb at 125 psi to his trailer with 6k axles that came with 16" ST E 80 psi tires.
He was a newby and bit into the bigger is better without doing any research or asking questions of the pros and cons of a H load range tire on a 6k axle.
time2roll
Nomad
Jan 19, 2017
"lite" or not if it came with 205-15-C it is all about the weight.
JIMNLIN
Explorer III
Jan 19, 2017
The OP has a Dutchman Lite. Sure a over tired trailer can/may get beat up with higher pressure tires......... and no I didn't say all TTs.
A different size or brand or a non lite TT isn't apples vs apples to the OP lite trailer.
With certain "lite" trailers it can make a difference how hard the tires are such as a 65 psi D tire which has a hard sidewall compared to a softer/flexy 50 psi sidewall C tire.

I upgraded my 11200 lb trailers tires from ST D to LT E isn't apples to apples for the OP trailer tire combo.

Moving up a load range sound good but may not be the best idea for "all" trailers.
mike-s
Explorer
Jan 19, 2017
Dannyabear1 wrote:
Tires are not mfd to be 'suspension components', the more they flex the hotter they will run, and then fail; ST tires should always be run at max pressure
Just wow. That couldn't be any more wrong. I suppose it's somewhat a matter of definition whether they're a part of the suspension, but tires are definitely taken into account in vehicle suspension design, and the pressure definitely affects the ride. Manufacturers actually publish charts giving a load/pressure relationship for ST tires, they are not meant to "always be run at max pressure" (even though that may be true for tires which are spec'd for use at the limit).
Huntindog
Explorer
Jan 19, 2017
The difference in ride is not the reason it is falling apart. I have LRE, and 80 psi on my last two TTs. 28K is much more than the average user will tow.
I am probably are in your class mileage wise.
This is not the first time you have posted about your rough ride. I would suggest that with your usage, some suspension upgrades would be money well spent. I would start with one of the rubber shocked equalizers... The brand of your choice. They are a cost effective way of making a dramatic improvement.
FWIW: My TT has been upgraded from 5200# axles/springs to 7000# axles/springs. And the tires from LRD to LRE. These mods were made to improve on the factory equipment, as I realize that my usage is much more severe than average.
westend
Explorer
Jan 19, 2017
So the question is, "Are the higher pressure D rated tires transferring more stress and vibration to the TT body?"
Probably but those particular failures may be from a poorly engineered installation schedule. You might have had that same damage with the "C" rated tires as replacements.

To accurately see what is going on inside your trailer on the road, you'd have to make an experiment that could be measurable with the conditions present. It could be as complex as vector accelerometer measurements or as simple as a shallow dish of water within another dish.

FWIW, I left a half filled soda can on a countertop one day. I drove about 100 mi before I stopped. The can was still in the same spot on the wooden countertop. I have torsion axles and shocks on a 5000 + lb trailer with 15" D rated Carlisles.
goducks10
Explorer
Jan 19, 2017
28,000 miles. Maybe your springs are half shot and not working right.
time2roll
Nomad
Jan 19, 2017
I made the same tire swap. Installed stiffer springs too. Has never ridden better. No issues here.
Dannyabear1
Explorer
Jan 19, 2017
Tires are not mfd to be 'suspension components', the more they flex the hotter they will run, and then fail; ST tires should always be run at max pressure
RinconVTR
Explorer
Jan 19, 2017
Well, yeah the higher weight rating + more psi = harder ride. No question about it. Is it so hard that its knocking things loose? Sure.

Did you get the new tires balanced? Highly recommended. Might also be an issue if you did not, the trailer might be shaking itself apart in addition to the harder ride doing the same thing.

Get the tires balanced and lower the tire PSI to 50-55. The load rating at this pressure will very likely be the same as the C's.

These load/inflation charts are not brand specific;
http://www.goodyearrvtires.com/pdfs/rv_inflation.pdf