StandUpGuy's trailer ride

[S. Heisley]

StandUpGuy wrote:

The bucking is up and down. The tires are filled at exactly the max pressure.

You say your trailer only weighs 1,000 pounds and it is bucking, not swaying? You might try to lower your tire pressure and see if that helps at all.

I copied this from somewhere on the forum and can't find it again to give credit; but, I'll share what was written anyway:

If I'm reading your question correctly, you want to know if running a certain tire pressure will do something good or bad for the trailer...Absolutely!

The way your finished, loaded trailer rides is directly effected by what tire pressure you're running. Running a very low air pressure will make the trailer more likely to wiggle and sway behind the tow vehicle. It will seem very bouncy and squishy and wear the tires on the outer edges. If a high PSI is used, the trailer will ride very harsh. Hitting bumps will make the trailer want to jump. The tires will also be over inflated and wear in the middle.

For even wear and a pleasant ride, there is an optimum PSI.

If you know the weight of your trailer loaded and ready, you're half way there. Take your trailer for example: GTW 1000. If balanced correctly, the tongue should have a weight of 100# and each tire should share the rest of the load at 450# each.

Lets say your trailer has 4.80-12 tires rated at a max load of 750# at 60psi. If you take your trailer weight knowing that only 450# is going to be riding on each tire, it's just a simple math formula.

Take your load per tire (450#), multiplied by the max PSI of the tire (60), divide that by the max load of the tire (750), and you get what should be your correct PSI for maximum ride and wear quality.

450x60= 27000/750= 36PSI

So, in this case, your trailer will perform best with a tire pressure right around 36PSI.

This formula can be applied for any tire as long as you know the max weight, PSI, and the actual weight it will be carrying.

Also, some roads are made in such a way that the trailer will bounce a tad. Driving in and out of my residential area, I feel that but not on the main streets around town. So, drive around and see if you feel the bounce on many streets or only certain ones.

The forum members can offer solutions; but, only you can find the proper answer(s) to your problem.

[StandUpGuy]

The bucking is up and down. The tires are filled at exactly the max pressure.

Is the bucking an action like a see-saw, where the tongue pushes down, then rises and repeats?
Or is it just the axle/wheels bouncing up and down, like happens on a very rough road?

Tires filled to the max, it they are designed to support 3000 pounds at max pressure will bounce like a childs rubber ball if they are only carrying a load of 1000 pounds.

Rob

The bucking action is like a see-saw pushing down on the tongue. On the first test run when my tongue weight was like 80 lbs the bucking was much more severe and on a bad dip in the road the bucking repeated after the bump 2 or 3 times. The next day after I adjusted the load and increased the tongue weight to about 142 lbs there was almost no bucking but when I hit a bigger rut there was just one buck and no second buck. So I feel I am close to having it ride decent but I have not done your suggested hiway tests yet.

[StandUpGuy]

StandUpGuy wrote:

The bucking is up and down. The tires are filled at exactly the max pressure.

You say your trailer only weighs 1,000 pounds and it is bucking, not swaying? You might try to lower your tire pressure and see if that helps at all.

I copied this from somewhere on the forum and can't find it again to give credit; but, I'll share what was written anyway:

If I'm reading your question correctly, you want to know if running a certain tire pressure will do something good or bad for the trailer...Absolutely!

The way your finished, loaded trailer rides is directly effected by what tire pressure you're running. Running a very low air pressure will make the trailer more likely to wiggle and sway behind the tow vehicle. It will seem very bouncy and squishy and wear the tires on the outer edges. If a high PSI is used, the trailer will ride very harsh. Hitting bumps will make the trailer want to jump. The tires will also be over inflated and wear in the middle.

For even wear and a pleasant ride, there is an optimum PSI.

If you know the weight of your trailer loaded and ready, you're half way there. Take your trailer for example: GTW 1000. If balanced correctly, the tongue should have a weight of 100# and each tire should share the rest of the load at 450# each.

Lets say your trailer has 4.80-12 tires rated at a max load of 750# at 60psi. If you take your trailer weight knowing that only 450# is going to be riding on each tire, it's just a simple math formula.

Take your load per tire (450#), multiplied by the max PSI of the tire (60), divide that by the max load of the tire (750), and you get what should be your correct PSI for maximum ride and wear quality.

450x60= 27000/750= 36PSI

So, in this case, your trailer will perform best with a tire pressure right around 36PSI.

This formula can be applied for any tire as long as you know the max weight, PSI, and the actual weight it will be carrying.

Also, some roads are made in such a way that the trailer will bounce a tad. Driving in and out of my residential area, I feel that but not on the main streets around town. So, drive around and see if you feel the bounce on many streets or only certain ones.

The forum members can offer solutions; but, only you can find the proper answer(s) to your problem.

You know I had light tongue weight on my first test drive and it bucked a lot. I had one low tire and one even lower on the other side. The next day I still had very low tires and increased my tongue weight and it rode much improved. So I took it out a third time to get air in the tires and I inflated them to the max psi. Then on my way back the ride was perhaps a little worse. So no doubt you are right with this suggestion. I think I had one way low tire and that was bad. Tomorrow I am going to increase my tongue weight just a little to 150 lbs and I will try that on side roads. Then I will let 5 lbs of air out of the tires and try it again. When I have it riding the best possible on side roads I will take it out on the hiway for more strenuous testing and see how it goes. Of course I need to get my actual trailer weight to figure out really what is going on and apply this formula to tire pressure, but it is a great bit of info to have, thanks.


I really appreciate all of the good suggestions from everybody.

[KCStudly]

Lengthening the tongue will help the trailer track, trail and back easier, but won't it also reduce the tongue weight ratio, since it will add relatively little weight, in effect shifting weight rearward.

Sorry to quote myself, but it seems you all are just arriving at the same conclusion I mentioned previously. Need my props, ya' know.

[StandUpGuy]

Lengthening the tongue will help the trailer track, trail and back easier, but won't it also reduce the tongue weight ratio, since it will add relatively little weight, in effect shifting weight rearward.

Sorry to quote myself, but it seems you all are just arriving at the same conclusion I mentioned previously. Need my props, ya' know.

Yes it looks like you were saying basically the same as Angib.

[StandUpGuy]

So another volley of test rides. Today I increased the tongue weight from 142 lbs. to 159lbs. I did not notice any difference riding on side streets. I did notice a slight difference on trailer level. I measured the trailer on a flat surface and the ride height was dead even from front to back. So the trailer is riding perfectly level. I then took the trailer for a ride on the highway. I went 57 mph on the way out and was passed by two semis that were going about maybe 8 mph faster than myself. There was no effect on the trailer at all. The trailer actually rode pretty nice on the highway. I hit small bumps and there was no big bucking and what little there was did not reverberate in to additioanl bucks. There was no bouncing on wheels so I did not decide to let any air out of tires yet. On my return trip on the highway I brought it up to 62 mph. Still rode fine. There was not much for sway just little tiny amounts of it. Very little. If I hit a dip and it swayed a litttle if very quickly stoped and did not continue into further sways. Then when I got off the highway it rode nice at fourty and only did I notice some bucking when I slowed below 30 mph and hit ruts and then there was some little bucking.

Now I did not get passed by semis going 70 mph passed me nor did I hit really bad road with big ruts or potholes.

So it seems to be pretty good and perhaps a little of it is my jitteres pulling it as I have little experience pulling a trailer at all. So my question is this: Is it possible I would see any benefit from lowering my rise on the hitch by an inch? Right now my trailers ride is perfectly level. Would there be a benefit to lowering the nose a tad?

[48Rob]

No,

Having the trailer level is important, as is having the combination level.
Tow vehicle and trailer being level prevents bucking from one or the other trying to "get straightened out".

Some of the sway and or bounce may well be just from being new to towing, or using this combination.

I would let a bit more air out of the tires and try again.
I would also continue with the highway tests until you are sure whatever sway remains is not a danger.

Common, unproblematic towing will always show a little movement while being passed.
When a vehicle passes you, you and your trailer will first be pushed sideways, and then pulled back.
If the tail end of the trailer actually sways/wags back and forth more than just a tiny bit, the rig is not yet stable.

Rob

[StandUpGuy]

No,

Having the trailer level is important, as is having the combination level.
Tow vehicle and trailer being level prevents bucking from one or the other trying to "get straightened out".

Some of the sway and or bounce may well be just from being new to towing, or using this combination.

I would let a bit more air out of the tires and try again.
I would also continue with the highway tests until you are sure whatever sway remains is not a danger.

Common, unproblematic towing will always show a little movement while being passed.
When a vehicle passes you, you and your trailer will first be pushed sideways, and then pulled back.
If the tail end of the trailer actually sways/wags back and forth more than just a tiny bit, the rig is not yet stable.

Rob

I think when I added the tongue weight from 142 lbs to 159lbs I saw no benefit. I think I will remove some of the weight and then do as you say and take a little air out of the tires and see what that does to the ride.

[StandUpGuy]

OK tests today. I removed a little of the air from the tires and went for a test ride. Some slight bucking on side streets at low speed and on the highway passing trucks had little to no affect on the trailer. The highway ride was good as it was before. no change with the slight air removal. So then I removed a little bit of the tongue weight down to 143 lbs. Again on the side streets with a dip I got a little bucking and on the highway it was good. None of these small adjustments hurt or helped the ride. I think I am in the optimal zone with say 140 lbs-150 lbs of tongue weight and near max tire pressure.

[StandUpGuy]

Get a different ball mount and don't shoot for dead level go a couple inches nose down. Towing attitude is a real big factor in the ride characteristics. It's a 20 dollar investment and I think you will be amazed the difference in the trailers road manners.

I was there to so it happens. I lengthened the tongue and dropped the ride angle and it is a totally different cat.

If you put the trailer tongue on a set of bathroom scales and measure the weight at 2" down vs your 1" or 2" up you will be shocked.

If you do let us know what kind of numbers you get.

All right I will do it.

I have a 4" rise on my ball mount and just picked up a 2" rise. I installed it and now I have the rear end more than an inch higher than the front. Here is a photo of it but it is not straIght from the side so its hard to tell the rear is higher in it. Later this afternoon I will take it for a test drive and report back on the results.

[StandUpGuy]

OK report back on my never ending trailer towing thread. I drove the trailer with the same weight as last time but with the ball dropped down two inches. I did not notice any change in in towing characteristics. I think I am about at optimal towing right now. The only other last thing I am going to do is greatly increase the tongue weight and see what happens just for the heck of it.

[KCStudly]

It is really difficult to tell the magnitude of the "objectionable" (maybe I should say "noticeable") towing conditions that you are describing, in the sense that it makes it hard for us to help from a remote position.

If I am reading between the lines of your latest towing descriptions correctly, it sounds as though what you are now describing might be totally normal behavior.

Notice all of the qualifiers that I just used?

I mean, are we talking princess-and-the-pea annoying , or Rock-of-Gibraltar-scared-to-leave-the-driveway annoying ?

Sounds to me like you have it just about licked.

[StandUpGuy]

It is really difficult to tell the magnitude of the "objectionable" (maybe I should say "noticeable") towing conditions that you are describing, in the sense that it makes it hard for us to help from a remote position.

If I am reading between the lines of your latest towing descriptions correctly, it sounds as though what you are now describing might be totally normal behavior.

Notice all of the qualifiers that I just used?

I mean, are we talking princess-and-the-pea annoying , or Rock-of-Gibraltar-scared-to-leave-the-driveway annoying ?

Sounds to me like you have it just about licked.

Yes I hear you. I was thinking the same thing that I am a towing "gringo" and just a little skidish. I think there is a little bit of bucking but it is at slow speed and on the highway all is cool. Maybe it is more like the Princess and the garbonzo bean.

[StandUpGuy]

OK the last test ...probably. I way loaded the front of the trailer and got the tongue weight to 190 lbs.. Now the last time I drive the trailer Iightened the tongue to like 134 lbs or something like that and reported no significant change in towing. This time I did notice a change. A little better actually. Same good towing on the highway but the side roads had better towing at low speeds. Less bucking.


So what to gather from this? Maybe when I had it at 150 something pounds tongue weight and dropped it to 130 something I did not notice a difference but maybe it was slightly worse and maybe with this increase it is slightly better than 150ish. I am concluding that over 150 lbs is probably a good thing. What do you think?

[High Desert]

Better is good! Maybe it's time to get an overall weight on the trailer to see what the percentages are looking like. I'd be curious to see that. I'm wondering if it may be a bit heavier than predicted?