Bouncing on Concrete Roads
We just finished our fourth trip with our new trailer. Been camping for years with a smaller trailer, but just moved to a 31'. I have a situation that I need to figure out when we are on roads th...
Forum Discussion
As was said by many here, there are things on your rig that can aggravate this.
"Some" of the aggravation factors:
Improper WD setup. (mostly from not enough weight moved forward causing front to back bucking known as porpoising)
WD bars too small for the loaded tongue weight.
A truck reciever that has too much flex for the loaded tongue weight.
Bad shocks on the truck.
Truck suspension rear axle beyond the door sticker rating (GAWR-RR)
Lack of shocks on the TT.
Lack of rubber equalizer on the TT if you have double eye leaf springs.
I'm sure there are more.
Out of all those factors the first one can oftentimes be the worst offender. However all of them have interactions that can make it worse when they are not right. But... there is always a but...
In my case there is a stretch of concrete road on the NYS Thruway (I-90) just outside the Buffalo area that will set my right off every time. This stretch of road is right before the Lackawanna exit toll both in the non toll area of I-90. The older concrete slabs have settled and they are not inline with each other. We go through that area about once a year and I'm sure this year it is still not changed.
If I'm doing 55mph the bucking is already in motion and anything approaching 60mph it gets really bad. Start slowing below 55, 1 mph at a time and you can feel it starting settle out. By 50 mph it almost stops.
I have upgraded to Blisten 4600 series shocks on the truck, I have upgraded the truck receiver to a 2 1/2" 1,700# loaded TW Reese Tow Beast receiver, the WD on the truck is optimized and confirmed by scale weights, the loaded TW on the camper is 16%, the truck has plenty of excess rear axle load limit (1,500# excess), the TT has Monroe shock absorbers and a Trail Aire rubber equalizer. All LT tires (TV & TT) are aired up for the load ratings and sidewall stiffness needed for stable towing.
That concrete road slab settling just finds the Natural Frequencyof my rig setup and sets it off. Speed is the only factor that I can adjust on the fly to stop it.
I can be on rough pothole patched or washboard patched joints black top and all I get is the jarring bounce but not the bucking oscillation that come from that stretch of concrete road with no potholes.
Optimize your rig in all areas and then the only thing left is often to slow down or change the truck or camper which is not going not happen in our case. A different length/weight camper or truck wheel base load ratings shifts the natural frequency point to something else. But it still may be in the normal highway towing range.
Hope this helps
John
"Some" of the aggravation factors:
Improper WD setup. (mostly from not enough weight moved forward causing front to back bucking known as porpoising)
WD bars too small for the loaded tongue weight.
A truck reciever that has too much flex for the loaded tongue weight.
Bad shocks on the truck.
Truck suspension rear axle beyond the door sticker rating (GAWR-RR)
Lack of shocks on the TT.
Lack of rubber equalizer on the TT if you have double eye leaf springs.
I'm sure there are more.
Out of all those factors the first one can oftentimes be the worst offender. However all of them have interactions that can make it worse when they are not right. But... there is always a but...
In my case there is a stretch of concrete road on the NYS Thruway (I-90) just outside the Buffalo area that will set my right off every time. This stretch of road is right before the Lackawanna exit toll both in the non toll area of I-90. The older concrete slabs have settled and they are not inline with each other. We go through that area about once a year and I'm sure this year it is still not changed.
If I'm doing 55mph the bucking is already in motion and anything approaching 60mph it gets really bad. Start slowing below 55, 1 mph at a time and you can feel it starting settle out. By 50 mph it almost stops.
I have upgraded to Blisten 4600 series shocks on the truck, I have upgraded the truck receiver to a 2 1/2" 1,700# loaded TW Reese Tow Beast receiver, the WD on the truck is optimized and confirmed by scale weights, the loaded TW on the camper is 16%, the truck has plenty of excess rear axle load limit (1,500# excess), the TT has Monroe shock absorbers and a Trail Aire rubber equalizer. All LT tires (TV & TT) are aired up for the load ratings and sidewall stiffness needed for stable towing.
That concrete road slab settling just finds the Natural Frequencyof my rig setup and sets it off. Speed is the only factor that I can adjust on the fly to stop it.
I can be on rough pothole patched or washboard patched joints black top and all I get is the jarring bounce but not the bucking oscillation that come from that stretch of concrete road with no potholes.
Optimize your rig in all areas and then the only thing left is often to slow down or change the truck or camper which is not going not happen in our case. A different length/weight camper or truck wheel base load ratings shifts the natural frequency point to something else. But it still may be in the normal highway towing range.
Hope this helps
John
