Towing for the first time... advise?
#16
08-19-2002, 08:47 PM
diligaf150
Where did you get your information?
First of all, let me say that I encourage all towers to experiment with towing proportions under stopping, accelerating braking (turn off electric brake controler under testing, as they can fail.)
Both trailer and hitch manufacturers recomend 10% accross the board. Utility trailer manufacturers often recommend 10-20%. Ever read the weight rating on a trailer coupler? Most people read the ratings on their hitch and leave it at that. There are many more factors than this. Areodynamics has little to do with swaying. Sure it "pulls" a little on the trailer, but minimally compared to the perpendicilar force of swaying. Ever notice trailer axles on a tractor-trailer are almost all the way to the back? Ever notice heavier fifth wheel trailers have the axles near the back? It makes no difference if it is a flatbed or a big wind sail of a travel trailer. The reason is that if the weight is centered over the axles, the trailer may "teeder" both forn to back and side to side. If your trailer "pops" up and down over bumps, railroad tracks, etc. the tounge wieght is insufficient. A properly loaded trailer should affect the ride very little, and the trailer/towing vehicle should not react independently (teedering or poping).
Trailer manufacurers often choose turning radius over proper wieght distribution, and put the axles too far forward. It seems that boat and travel trailer manufacurers are more prone to do this, but many utility trailer manufacturers do this as well. Ever notice boat trailers are universal to many designs and not calculated for each boat?
Vehicle manufacturers consider mainly drivetrain configurations and overall weight to rate towing capacity. Different gearing ratios are a major factor in towing capacities. Im not saying that suspension and braking aren't factord in, They consider maximum braking power, towing power, and overall weight applied to the axles in general, but they don't consider loading ratios in thier ratings. Different loading ratios are required for different trailers. For example, as a rule, fifth wheel trailers pull easier, brake better, and ride softer on the suspension than bumper pull trailers. Yes they pull easier. The difference is in the position that the weight is loaded on a truck and where it "pulls" from. If the proper tounge weight causes squatting etc. on a pulling vehicle in order to perform properly, the towing vehicles suspension is insufficient, despite vehicle manufacturers calculations based mainly on drivelines.
Most hitches are rated in this manner as well, but most are rated at 10% of the maximum hitch capacity. This does not mean that you cannot apply 500lbs tounge load on a 4,000lb trailer when the hitch is rated for 500/5,000. I am not saying that 400lbs would not be sufficient, but 500lbs would not overload the rated capacity if that is required for proper towing.
Besides swaying, acceleration and braking is an important factor in weight distribution. If the tounge weight is too light, the restrictive force of the trailer accelerating "pulls" upward. Most trailers are loaded in such a manner that the weight (center of mass) is higher than the hitch. When the hitch pulls on the trailer, the restrictive force of the weight "teeders" the trailer back, displacing tounge weight and weight applied to the back of the towing vehicle.
The braking action on a trailer with insufficient tounge weight reacts somewhat similarly. When the towing vehicle brakes, the forward traveling force is applied higher than the brakes. This shifts a great amount of weight to the front of the vehicle. If the tounge weight is not sufficient to level the vehicle and offset the weight that is "shifted" forward, the front brakes do the majority of the work. This causes loose steering while braking, overheating of the front brakes, and even jack knifing under extreme conditions when the back tires loose sufficient traction while the front tires are braking hard.
Most people dont notice the latter braking problems, as they have trailer braking systems that offset some of the resultant forces. They will offset a larger portion of these forces if the weight is farther forward on the trailer (the difference in the distance between the center of mass of the load, and the braking axle). Unfortunantely, trailer brakes are subject to failure.
I encourage all towers to experiment with tounge weight. Turn off electric brake controlers and attempt stopping with differing loading proportions. Usually its not a flat proportion. Pulling one of 4 trailers at least 3x a week with many varying loads, I have found that each pull different and require different loading positions. Unfortunantely, you cant go by book ratings, as all factors aren't and can't be considered in manufacturers ratings.
I will be surprised if anybody read this far .
6-8% when trailering Boats, due to the fact they are more aerodynamic. up to 10% when trailering campers and what not.
First of all, let me say that I encourage all towers to experiment with towing proportions under stopping, accelerating braking (turn off electric brake controler under testing, as they can fail.)
Both trailer and hitch manufacturers recomend 10% accross the board. Utility trailer manufacturers often recommend 10-20%. Ever read the weight rating on a trailer coupler? Most people read the ratings on their hitch and leave it at that. There are many more factors than this. Areodynamics has little to do with swaying. Sure it "pulls" a little on the trailer, but minimally compared to the perpendicilar force of swaying. Ever notice trailer axles on a tractor-trailer are almost all the way to the back? Ever notice heavier fifth wheel trailers have the axles near the back? It makes no difference if it is a flatbed or a big wind sail of a travel trailer. The reason is that if the weight is centered over the axles, the trailer may "teeder" both forn to back and side to side. If your trailer "pops" up and down over bumps, railroad tracks, etc. the tounge wieght is insufficient. A properly loaded trailer should affect the ride very little, and the trailer/towing vehicle should not react independently (teedering or poping).
Trailer manufacurers often choose turning radius over proper wieght distribution, and put the axles too far forward. It seems that boat and travel trailer manufacurers are more prone to do this, but many utility trailer manufacturers do this as well. Ever notice boat trailers are universal to many designs and not calculated for each boat?
Vehicle manufacturers consider mainly drivetrain configurations and overall weight to rate towing capacity. Different gearing ratios are a major factor in towing capacities. Im not saying that suspension and braking aren't factord in, They consider maximum braking power, towing power, and overall weight applied to the axles in general, but they don't consider loading ratios in thier ratings. Different loading ratios are required for different trailers. For example, as a rule, fifth wheel trailers pull easier, brake better, and ride softer on the suspension than bumper pull trailers. Yes they pull easier. The difference is in the position that the weight is loaded on a truck and where it "pulls" from. If the proper tounge weight causes squatting etc. on a pulling vehicle in order to perform properly, the towing vehicles suspension is insufficient, despite vehicle manufacturers calculations based mainly on drivelines.
Most hitches are rated in this manner as well, but most are rated at 10% of the maximum hitch capacity. This does not mean that you cannot apply 500lbs tounge load on a 4,000lb trailer when the hitch is rated for 500/5,000. I am not saying that 400lbs would not be sufficient, but 500lbs would not overload the rated capacity if that is required for proper towing.
Besides swaying, acceleration and braking is an important factor in weight distribution. If the tounge weight is too light, the restrictive force of the trailer accelerating "pulls" upward. Most trailers are loaded in such a manner that the weight (center of mass) is higher than the hitch. When the hitch pulls on the trailer, the restrictive force of the weight "teeders" the trailer back, displacing tounge weight and weight applied to the back of the towing vehicle.
The braking action on a trailer with insufficient tounge weight reacts somewhat similarly. When the towing vehicle brakes, the forward traveling force is applied higher than the brakes. This shifts a great amount of weight to the front of the vehicle. If the tounge weight is not sufficient to level the vehicle and offset the weight that is "shifted" forward, the front brakes do the majority of the work. This causes loose steering while braking, overheating of the front brakes, and even jack knifing under extreme conditions when the back tires loose sufficient traction while the front tires are braking hard.
Most people dont notice the latter braking problems, as they have trailer braking systems that offset some of the resultant forces. They will offset a larger portion of these forces if the weight is farther forward on the trailer (the difference in the distance between the center of mass of the load, and the braking axle). Unfortunantely, trailer brakes are subject to failure.
I encourage all towers to experiment with tounge weight. Turn off electric brake controlers and attempt stopping with differing loading proportions. Usually its not a flat proportion. Pulling one of 4 trailers at least 3x a week with many varying loads, I have found that each pull different and require different loading positions. Unfortunantely, you cant go by book ratings, as all factors aren't and can't be considered in manufacturers ratings.
I will be surprised if anybody read this far .
#17
08-19-2002, 11:05 PM
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