Hi all,
My Fleetwood/Coleman Taos goes into a rhythmic up-and-down motion on certain concrete highways. Most roads it's fine. I've tried several TVs, so that doesn't seem to be the issue. I've moved the axle to the alternate spring position, and that made it worse, so I assume it's related to the hitch ball-to-axle distance.
Anyone else noticed this with a Taos? Any fixes someone might like to suggest?
Glenn
Put more stuff up front to increase the camper's tongue weight and see what you think.
Austinado,
Tried that, no change. It's not a sway issue it's an up and down motion directly related to the pavement type.
Glenn
Right, I know it's not sway.
Some people have previously posted that they've improved or completely alleviated the bounce by changing the tongue weight.
Concrete freeways are pretty miserable to drive on because they have an expansion joint every umpteen feet. That set's the vehicle's suspension into a rhythmic oscillation (resonance) and about the only way to modify that is to change your speed.
Up and down motion of the PU is generally caused by low tongue weight.
Coleman/Fleetwood recommends about 10-15 % of the weight of the loaded PU be on the tongue. In your case, about 250 lbs of tongue weight should do it. Use a bathroom scale to check it.
As others stated in their replies, move some of the load inside the PU forward of the axel and see if this eliminates the bounce.
Question: When you moved the axel, did you move it the direction toward the tongue, or further away?
If my theory is correct, you moved it closer to the tongue and that made the bounce condition worse.
The problem might be caused by excessive frame flexing. Obviously trailer frames were designed/made to flex to compensate for an uneven road surface and there has to be that give and take otherwise something is sure to break. But when there is too much frame flex it can cause a reaction with the suspension components and then you have a trailer with the "bouncies". The problem then can lead to premature metal fatigue such as a leaf spring breaking when the trailer is not even overloaded. The solution in this case is to either beef up the trailer frame or the trailer suspension. Since doing much with the frame is not very practical, maybe going to a heavier set of leaf springs might be the answer to the problem.
The Dexter Axle website gets into this excessive trailer frame flex and I believe it's in the section of designing your own trailer.
I have a smaller 8' box Starcraft that had a bad case of the "bouncies" and the answer was going to heavier springs. It came new with a 2,000 lb capacity axle with 1,000 lb rated leaf springs on each side. I replaced the 1,000 pounders with 1,400 lb springs (four leaf ... the previous was two leaf).
You cannot believe how the heavier springs smoothed out the ride. And Starcarft soon corrected the situation doing the same thing with their future smaller models.
Fly
I read a post on another forum about how much better their pup towed after having the camper's tires balanced.Tires from the factory are not balanced.I bought my tires last year and after reading the post I checked and saw they weren't balanced.I called where I bought the tires and they said they don't usually balance tires that were not balanced when the tires are changed.They told me to bring them back and they would balance them,no charge.After they balanced them I noticed a BIG weight on one side of the wheel and another smaller weight on the opposite side.This was an indication to me of how out of balance the wheels were.I was having the same problem as you and have not pulled my camper since having the tires balanced.I'm hoping it will help.Imagine spinning a 30# unbalanced tire on an axle at 70 mph.Balancing is bound to make for smoother towing.
I always have my trailer (utility, car tow dolly, or PU) wheels balanced.
One thing to be careful about with trailer tires and balancing. This may only apply to certain wheels.
For some trailer wheels, there is no standard for centricity of the center hole. If a tire with an out-of-center hole is balanced using that center hole, you could make the balance worse, not better.
Always insist that your trailer tires be balanced by the lug holes, not the center hole, or don't get them balanced at all.
On the bounce issue: One solution, which is not very popular, is to slow down. Sometimes, a 10% reduction in speed can result in a much larger reduction in trailer bouncing.
We found a 90-100% elimination in bounce when we went to a weight distributing hitch, but a WDH is extreme overkill for a Taos.
Don't overload the trailer (though a too light trailer is more likely to bounce than a too heavy one), and don't over-inflate the tires.
Austin
I have had the same problem with my 95 Coleman Avalon ever since I bought it. I have tried many things with little result to cure the problem. I changed the shocks on my tow vehicle to heavy duty ones with helped only slightly. I added shock absorbers to the camper with no real noticeable difference. I use a weight distribution hitch with sway bar, no difference. I makes no difference it I have the battery weight on the tongue or the bikes on the bike rack on the rear of the trailer. On black topped roads it is smooth as can be with no bouncing but on concrete roads- new or old- it does the bouncing thing. As others have said it is less at slower speeds so I usually don't go any faster than around 58 MPH on concrete roads. Any faster and the problem is worse. If any one ever comes up with a solution for this problem PLEASE let us know.
Thanks all, for the replies.
Hoppy, you're correct that when I moved the axle it was closer to the hitch. Moved it back to the original position and the bouncing went back to its original ways.
The Taos weighs about 1200, and I've got 150# on the hitch. When I moved the axle, the hitch weight was still about 145#, so it's more related to the axle-to-hitch distance.
Looks like I'm going to have to slow down on the concrete highways. Damn.
Glenn
I have a sailboat/trailer combo that weighs about 2500+ lbs. When I bought it in 1999, the trailer had bias ply ST tires on it. After replacing the tires with ST radial tires, I noticed the trailer had less bounce while towing, and less lateral jumping when towing over things like railroad crossings.
I'm a believer in radial trailer (ST) tires. I just wish my new Starcraft had come with them...
I have had the same problem with bounce on both of the PU trailers I have owned. I haven't found anything that really makes a difference. :D
Quote from: GlennS;209007Thanks all, for the replies.
Hoppy, you're correct that when I moved the axle it was closer to the hitch. Moved it back to the original position and the bouncing went back to its original ways.
The Taos weighs about 1200, and I've got 150# on the hitch. When I moved the axle, the hitch weight was still about 145#, so it's more related to the axle-to-hitch distance.
Looks like I'm going to have to slow down on the concrete highways. Damn.
Glenn
One last suggestion is to actually weigh the Taos loaded up for camping.
Take it over to a weigh station and weigh it in three steps.
First unhook it from the TV just before you get on the scale with the dolly jack in the down position.
Then pull the PU with only the dolly jack on the scale. This will give you the actual tongue weight. Record this number.
Next pull the PU so that both wheels and the dolly jack are on the scale. This will give you the total PU weight. Record this number.
Next pull the PU forward so only the wheels are on the scale. This will give you the actual axel weight. Record this number.
Once you have completed the three steps, the tongue weight should be in the 12 -15 % range of the total PU weight.
If it is, then moving the axel won't improve the bounce much.
The only other suggestion is moving any cargo inside the PU forward of the axel to help minimize the bounce, increasing the tongue weight a small degree.
Hope this helps.
Hoppy, I don't think that getting more weight on the tongue of his camper will help, although I could be wrong. My Coleman has the storage trunk on the front which is full, although not all heavy items. I also have two twenty pound LP tanks and the battery on the tongue. My camper also has the swing level galley which is located ahead of the axle and is fairly heavily loaded. I have the same problem with bounce as the original poster has on concrete roads but not on black topped roads.
Guys.....it's just the expansion joints in the concrete. Concrete freeways are built in panels and the change and gap from panel to panel, every 20' or whatever the magic expansion joint distance is, is what's causing all the bouncing. There's nothing you can do to improve it other than slowing down, or speeding up, until you find the magic speed at which your particular wheelbase doesn't oscillate as much.
Good advice Todd especially when hitting the 101 down around the Oxnard area by where Costco is. Even with out a trailer, that stretch of road is bouncy.
Quote from: austinado16;210105Guys.....it's just the expansion joints in the concrete. Concrete freeways are built in panels and the change and gap from panel to panel, every 20' or whatever the magic expansion joint distance is, is what's causing all the bouncing. There's nothing you can do to improve it other than slowing down, or speeding up, until you find the magic speed at which your particular wheelbase doesn't oscillate as much.
Yeah, remember when that whole section of 101 through Santa Maria was still concrete? My DW, then GF, had an '85 Toyota Tercel. That thing felt like it had 3 flat tires when driven through there due to the suspension geometry and wheelbase (I couldn't sell that car fast enough once we traded rings!:p)
We have some major east/west ~ north/south xways that have heavy truck traffic. Those 18 wheelers pounding those sections of concrete between the expansion joints can really get some dips created and pulling a popup trailer along some of those sections is a real challenge. For me speed is the key to the extreme of the bounce. Also, these major expressways are under constant repair for this very condition, along with the concrete disintergration making for those huge pot holes!
Fly
Yes I remember that stretch alright. The tire slap in this section was very loud and Caltrans first tried grinding and puting grooves in the cement and then finally black topped over it. At least the cement is a good base for blacktop.
Side note off topic of bouncing. The stretch through Nipomo is a pleasant drive now that Caltrans has resurfaced this area. Road noise is SIGNIFICANTLY reduced!
I use one of these:
http://www.nextag.com/Robin-Industries-Shock-Absorbing-640509911/prices-html
which really seems to help. At least it means the trailer doesn't jerk on the tow vehicle as badly. That and well balanced tires have really improved the ride with my Yuma. It was bouncing pretty bad when I first got it. Altering the tongue weight just didn't help.