What's new
By:
Filters

Camping trailer tends to bounce / unload

lpukas2

lpukas2

Maintains those stupid things that fly
Joined
Jul 8, 2021
Member Number
4166
Messages
105
Loc
Vail, AZ
Would like everyone's opinion / wisdom on this.

Bit of history..... Built trailer in 2017, box is 48" by 90", tongue is 96" from the axle, 3500 pound straight axle and matching springs, frame sits 24" from the ground, figure trailer is 1400 pounds fully loaded.

When I originally built the trailer I used shit ass used tires and it pulled great. Tires are 33-12.5R15, originally set them up same as the Jeep. In 2018 I put on brand new Falken tires, nothing else changed on the trailer. Ever since I put on these new tires the trailer will unload, bounce bad on bumps, rocks etc... It's bad enough that i put the trailer on its side once on the trail. Its bad enough that even pulling it on roads I get apprehensive. Doesn't matter if I'm pulling it with the Jeep or the truck.

On another note: I built the exact same trailer for a buddy, he has used tires and I noticed that when I'm following him, his trailer does not unload.

My thinking is that these new tires have never been broken in from being on a normal vehicle, never had the weight to soften them up.

Ideas? I would prefer to keep these tires and not go back to used tires and its hard to find used 15" tires no days.

1. Extend the tongue a bit, the tongue is removable and this is no big deal.

2. Decrease tire psi to around 5, I have tried increasing and decreasing the pressure but haven't gone below 12psi

3. Pull a spring out of the pack

thumbnail_image_6483441.jpg
 
lpukas2 said:
"C" same as the previously used tires
Click to expand...
So 2500#'s per tire or so.

I've found that weight capacity tends to track pretty well with tire pressure so if you have 750 pounds on a tire rated for 2500 you should be running around 30-35% of max pressure.

Does the trailer have shocks?

The springs may be the same story. If they are a 3500# pack like the axle I'd maybe look into putting a pack for a 2000# axle in, or pulling a leaf.

When I built my little 7x10 atv trailer I used a 3500# axle so that I would have spare parts for my big flatbed. I used lighter spring packs though and they were the same size as the 3500 springs just thinner leaves.
 
No shocks

Not sure if there is even room for shocks, they would be at a pretty good angle.

Everything I've read on trailer shocks said they are worthless, maybe bad info?
 
lpukas2 said:
No shocks

Not sure if there is even room for shocks, they would be at a pretty good angle.

Everything I've read on trailer shocks said they are worthless, maybe bad info?
Click to expand...
I think it depends on application. I know we started putting shocks on my parents travel trailers 15 years ago and their stuff gets way less beat up inside ever sence.

I think on your typical car trailer where the bulk of the weight has its own suspension that maybe they don't matter as much. I know my car trailer bounces all over the fucking place when its empty.
 
Tires really need to be that wide? Any reason why can’t you just run skinny ones? Tall and wide tires have lot of surface area in contact to ground, defeating any attempt to soften the ride at lower pressure.

I vote pulling a leaf or swap to 2000lbs springs and try again, possibly add shocks for good measure. I think shocks from a 18 wheeler cab will work well as they aren’t super long and small.
 
lpukas2 said:
No shocks

Not sure if there is even room for shocks, they would be at a pretty good angle.

Everything I've read on trailer shocks said they are worthless, maybe bad info?
Click to expand...

i put shocks on my car hauler last year. IMHO, big difference with and w/o weight.
 
rockota said:
i put shocks on my car hauler last year. IMHO, big difference with and w/o weight.
Click to expand...
How, what did it improved your car hauler? Genuinely curious, as I never wished I had shocks on my trailers, except maybe my 4’ by 6’ utility trailer to alleviate the bouncing when unloaded.
 
TrailTamer said:
How, what did it improved your car hauler? Genuinely curious, as I never wished I had shocks on my trailers, except maybe my 4’ by 6’ utility trailer to alleviate the bouncing when unloaded.
Click to expand...

reduced bouncing considerably, both loaded and unloaded. Doesn't react as erratic with expansion joints or rough roads. Honestly, it reduces effort to tow, IMHO.

If you've never wished you've had shocks on trailers, it's because you don't know what it's like to have shocks on trailers. :flipoff2:
 
I'm assuming you're running the same tire pressures as before? As you had "shit ass used" tires before and now brand new tires, I'm sort of thinking that the sidewalls were more soft and pliable with the used tires, giving it some more cushion (like the shocks would). Even though the new tires are the same load range, the sidewalls are probably a lot stiffer - even with the exact same tire new vs. used.

The other thing would be different manufacturer / "model" of tire. Again, even with the same load range, some tires have more sidewall belts than others and would be a lot firmer.
 
rockota said:
If you've never wished you've had shocks on trailers, it's because you don't know what it's like to have shocks on trailers. :flipoff2:
Click to expand...
This. Takes a lot of the bounce/jerk/sway out of the trailer. I have a similar sized trailer to the OP. You forget it's back there sometimes it so smooth. Running general at2's on it because fuck trailer tires.
 
I think you had too much spring from the get go, I would look at the spring specs of 2k springs and adjust my pack to try to match them. What is the weight of the new tires compared to the old ones, maybe an unsprung weight issue. As an experiment I would also load 1k of weight on the trailer and see how that effects things. Maybe aluminum rims to reduce unsprung weight. I currently own 6 trailers and have had at least another half dozen, have built 3 or 4 and have never felt the needs for shocks. I would also try lowering the air pressure in the tires and use a non contact thermometer to monitor temps until I ran out of nerve. Id balance the tires just so I could say i did it.
 
I put shocks on our fifth wheel. It had provisions to run them, just weren’t put on at the factory. It made quite a bit of difference. I’d guess you have too much spring for the load. Your older tires probably had less stiff sidewalls, making the ride smoother. I’d try pulling leaf’s outta the pack. You’ve got nothing to loose. You can always put em back.
 
I have a similar setup, similar weight. Smaller tires because station wagon. 3500lb axle, 2000lb springs. Rides pretty well. If I really hit a rock hard it will bounce some but not a concerning level. Run the tires at 40psi for all around use

At some point I will figure out how to do shocks on it, just havent gotten around to sourcing what rate I need
 
Shocks dampen spring oscillation. You probably need to pull a leaf or go softer, and some generic Monroe’s.
 
So after being on the look out for the last month for a used axle. I scored these today for a good price of 200 bucks. 2 3500 pound axle, 6 rims that magically are the same 5 on 4.5 as my other trailer, and 4 springs off a call hauler. Tires are garbage and the springs are more than likely garbage as well.
thumbnail_image_50427137.jpg
 
TrailTamer said:
Tires really need to be that wide? Any reason why can’t you just run skinny ones? Tall and wide tires have lot of surface area in contact to ground, defeating any attempt to soften the ride at lower pressure.

I vote pulling a leaf or swap to 2000lbs springs and try again, possibly add shocks for good measure. I think shocks from a 18 wheeler cab will work well as they aren’t super long and small.
Click to expand...
The tires are like that due to originally making them the same as the Jeep, then came along the axle swap. They don't need to be those rims / tires anymore but the tires are new and I don't really want to spend money on new tires. I have no other use for those tires.

PAToyota said:
I'm assuming you're running the same tire pressures as before? As you had "shit ass used" tires before and now brand new tires, I'm sort of thinking that the sidewalls were more soft and pliable with the used tires, giving it some more cushion (like the shocks would). Even though the new tires are the same load range, the sidewalls are probably a lot stiffer - even with the exact same tire new vs. used.

The other thing would be different manufacturer / "model" of tire. Again, even with the same load range, some tires have more sidewall belts than others and would be a lot firmer.
Click to expand...
This is what I'm thinking.... The old used tires with soft sidewalls hid the fact that the springs are too stiff for that light of a trailer.

I'm going to order up some 1000 pound springs Monday if I cant find them local. The springs are 27" long so not everyone has them.

If this doesn't work, I now have narrower 5" rims and will have to suck up and buy new tires.
 
i would lower the tires to 6-8psi and drive it down the highway for a bit and heat them up

i agree with changing springs, i built an off road trailer and used some jeep xj leaf springs, thing rode super smooth
 
Well finally got the 1000# springs installed. Pulls nice but is very soft, took it for a short trip down a dirt road and hit all the holes I could. It definitely floats more and does no unload. We will see what another 400 pounds does to it on the upcoming camping trip.
 
You must log in or register to reply here.
Top Back Refresh