Tongue Weight Rating
Hello, We are buying a trailer for our daughter and son-in-law. They now have a Ford Expedition with 8,900# tow rating. 80% of that is 7,120#, but they should stay below 7,000# loaded (5,500 to 6...
Forum Discussion
Definitions, Definitions, Definitions
For the past seven years, I have been citing
Regulation VESC-5: Min Req for Motor Vehicle Connecting Devices and Towing Methods published by the
Vehicle Equipment Safety Commission (VESC).
All that time, I've assumed that "hitch" in VESC-5 referred to the device which is inserted into the receiver and holds the ball -- what we typically refer to as a "weight distribution hitch".
All that time, I've been searching for a similar regulation or specification which pertains to what I've been calling the "receiver". I've seen receivers which had the V-5 certification, but never was able to find the testing spec.
I decided to take another closer look at VESC-5 to see if I could find any reference to a receiver. I found that, for seven years, I've been overlooking the obvious.
The following are excerpts from VESC-5:
3.6 "Hitch" defined for specific uses under Section 3.6(a. and b. below), generally means that part of the primary connecting system normally mounted on the towing vehicle, including a ball-support platform and those components which are attached to the towing vehicle.
3.6.a "Weight Distributing Hitch" means a mechanical device that connects the trailer to the towing vehicle and by means of leverage applied on both trailer and towing vehicle structures, when properly adjusted, distributes the imposed vertical load at the hitch and coupling connection between structures of towing vehicle and trailer. The towing vehicle thus tends to retain a level position with respect to the road.
3.6.b "Weight Carrying Hitch" means a mechanical and/or structural device that connects the trailer to the towing vehicle, and that does not employ features designed to redistribute the load imposed at the hitch and coupling connection.---
(bold added for emphasis)
The word, "receiver", is not used. Instead, VESC-5 uses the phrase, "those components which are attached to the towing vehicle".
3.8 "Maximum Vertical Load on Hitch (Tongue Weight)" means the vertical downward static force exerted on the hitch by the coupling at the point of connection of coupling and hitch with weight distribution features or devices, if any, deactivated. Tongue weight is measured at the trailer coupling, with the trailer on a level surface (detached from the hitch), and with trailer consumables and cargo in maximum loaded conditions.
5.3 Attachment of Hitch. Each hitch shall be attached to the structural member or members of the towing vehicle---
Indicating that the receiver is an integral part of the hitch assembly.
5.4 Maximum Vertical Load on Hitch (Tongue Weight). The weight load carried by the hitch at its connection with the trailer coupling shall not, when on a level surface, exceed the maximum tongue weight recommended by the manufacturer for the hitch.
I believe this establishes the relationship between receiver rating and tongue weight.
Page 14. 3. Each hitch, when tested as specified above, shall be capable of withstanding the forces applied in accordance with footnote (2), immediately above, without causing permanent deformation of the ball platform, such that the final position of the ball axis shall not depart more than five degrees from its original, nominally vertical, position.
Obviously, the shank and ball platform are inserted into the receiver prior to test loading -- they are not part of the test loading.
Page A-2 TEST PROTOCOL FOR CONNECTING DEVICES AND TOWING METHODS WITH SUMMARY OF RESULTS
Step 2. Attach the hitch to a non-yielding restraining fixture, utilizing only the attaching means recommended by the manufacturer for hitch-to-car attachment.
Step 4. Attach a ball to the ball support platform in the manner recommended by the manufacturer.
For me, the mystery is solved -- VESC-5 is a specification for simultaneous testing of a complete connecting system consisting of receiver, shank, and ball mount.
The tongue weight rating refers to the vertical load imposed on the ball mount by the trailer coupler.
Others might have a different interpretation of VESC-5.
Ron
For the past seven years, I have been citing
Regulation VESC-5: Min Req for Motor Vehicle Connecting Devices and Towing Methods published by the
Vehicle Equipment Safety Commission (VESC).
All that time, I've assumed that "hitch" in VESC-5 referred to the device which is inserted into the receiver and holds the ball -- what we typically refer to as a "weight distribution hitch".
All that time, I've been searching for a similar regulation or specification which pertains to what I've been calling the "receiver". I've seen receivers which had the V-5 certification, but never was able to find the testing spec.
I decided to take another closer look at VESC-5 to see if I could find any reference to a receiver. I found that, for seven years, I've been overlooking the obvious.
The following are excerpts from VESC-5:
3.6 "Hitch" defined for specific uses under Section 3.6(a. and b. below), generally means that part of the primary connecting system normally mounted on the towing vehicle, including a ball-support platform and those components which are attached to the towing vehicle.
3.6.a "Weight Distributing Hitch" means a mechanical device that connects the trailer to the towing vehicle and by means of leverage applied on both trailer and towing vehicle structures, when properly adjusted, distributes the imposed vertical load at the hitch and coupling connection between structures of towing vehicle and trailer. The towing vehicle thus tends to retain a level position with respect to the road.
3.6.b "Weight Carrying Hitch" means a mechanical and/or structural device that connects the trailer to the towing vehicle, and that does not employ features designed to redistribute the load imposed at the hitch and coupling connection.---
(bold added for emphasis)
The word, "receiver", is not used. Instead, VESC-5 uses the phrase, "those components which are attached to the towing vehicle".
3.8 "Maximum Vertical Load on Hitch (Tongue Weight)" means the vertical downward static force exerted on the hitch by the coupling at the point of connection of coupling and hitch with weight distribution features or devices, if any, deactivated. Tongue weight is measured at the trailer coupling, with the trailer on a level surface (detached from the hitch), and with trailer consumables and cargo in maximum loaded conditions.
5.3 Attachment of Hitch. Each hitch shall be attached to the structural member or members of the towing vehicle---
Indicating that the receiver is an integral part of the hitch assembly.
5.4 Maximum Vertical Load on Hitch (Tongue Weight). The weight load carried by the hitch at its connection with the trailer coupling shall not, when on a level surface, exceed the maximum tongue weight recommended by the manufacturer for the hitch.
I believe this establishes the relationship between receiver rating and tongue weight.
Page 14. 3. Each hitch, when tested as specified above, shall be capable of withstanding the forces applied in accordance with footnote (2), immediately above, without causing permanent deformation of the ball platform, such that the final position of the ball axis shall not depart more than five degrees from its original, nominally vertical, position.
Obviously, the shank and ball platform are inserted into the receiver prior to test loading -- they are not part of the test loading.
Page A-2 TEST PROTOCOL FOR CONNECTING DEVICES AND TOWING METHODS WITH SUMMARY OF RESULTS
Step 2. Attach the hitch to a non-yielding restraining fixture, utilizing only the attaching means recommended by the manufacturer for hitch-to-car attachment.
Step 4. Attach a ball to the ball support platform in the manner recommended by the manufacturer.
For me, the mystery is solved -- VESC-5 is a specification for simultaneous testing of a complete connecting system consisting of receiver, shank, and ball mount.
The tongue weight rating refers to the vertical load imposed on the ball mount by the trailer coupler.
Others might have a different interpretation of VESC-5.
Ron
