Formula for tongue weight?

[oxygen]

Is the following a correct way to calculate tw?
[tv rear axle (tt attached, wd disconnected) minus tv rear axle (no tt)] minus
[(front axle tv, no tt) minus (front axle tv, tt attached, wd disconnected)]

or is the following also correct?

[ (tv weight with bars engaged) minus (tv weight , no tt) ] plus [ (tt weight with bars engaged ) minus ( tt weight unhitched ) ]

[RCMAN46]

The number one cause of a trailer swaying is low tongue weight.

If you want a trailer to tow well the tongue weight most likely will have to be greater than 10%.

Also to make sure your are in the limits of your trailer hitch you have to know your tongue weight.

That is why I know what my real tongue weight is from my CAT scale numbers then there is no guessing.

[gijoecam]

Indeed, those are the two concerns. Even with weight distribution, one must still ensure that the tongue weight does not exceed the receiver's capability. The rule of thumb is just that: a generalization, but a good reference point. Outside the 10-15% TW range, things can often make for an unpleasant towing experience. There are always exceptions, but it is a pretty decent reference value that can be used.

But as was mentioned, ultimately, the actual axle weights are what matters.

[jerem0621]

Ryan*Elli wrote:
Why do people worry about the TW then using a WD hitch that transfers weight to the steer axle and TT axle? To me these number mean less than the actual weights one tows with. Your towing setup/weights are more of a concern. Additionally, I get the "rules of thumbs" with ratios but what is the "rule of thumb" regarding what percent of weight is transferred while using the WD hitch? Based on my experience its a lot more than you would think. Its not the 10-20% I have seen in threads. I saw a few hundred pound increase on my steer axle once I used the WD. Using the WD is using technology in your favor.

I agree with you to some degree. I am much more concerned about the TV steering and braking correctly than I am about the specific tongue weight.

Where my concern is in the receiver itself. I want to make sure its up to the task and can handle the torque of the WD hitch.

Great quote, "Using the WD is using technology in your favor."

Thanks!

Jeremiah

[Ryan_Elli1]

Why do people worry about the TW then using a WD hitch that transfers weight to the steer axle and TT axle? To me these number mean less than the actual weights one tows with. Your towing setup/weights are more of a concern. Additionally, I get the "rules of thumbs" with ratios but what is the "rule of thumb" regarding what percent of weight is transferred while using the WD hitch? Based on my experience its a lot more than you would think. Its not the 10-20% I have seen in threads. I saw a few hundred pound increase on my steer axle once I used the WD. Using the WD is using technology in your favor.

[RCMAN46]

The whole purpose of determining tongue weight is to calculate the tongue weight as a percentage of the total trailer weight.

Experience by thousands of RVer's has shown 15% will give best towing characteristics and some have found they can go as low as 10%

The WD system is actually connected to the TV and would not be considered in this calculation as is the trailer hitch not included in the tongue weight calculation.

[oxygen]

Strictly speaking -- the shank and ball mount should be considered part of the TV and the bars should be considered part of the TT.
However, I think it's easier, and sufficient, to treat the entire WDH as part of the TV.

Ron

I added the quote above from Bob Gratz, who had responded to one of my previous weight questions.

[oxygen]

jerem0621 wrote:

gijoecam wrote:

RJCorazza wrote:
When weighing without the WDH, I believe you will need to add the bar weight to tongue weight ( if they were totally removed.).

Why? They are not part of the trailer tongue weight applied to the ball.

True. But they are both bearing down on the receiver.

Some folks suggest you weigh the tv with hitch head and bars attached to tv. This weight is part of your payload weight.

[jerem0621]

gijoecam wrote:

RJCorazza wrote:
When weighing without the WDH, I believe you will need to add the bar weight to tongue weight ( if they were totally removed.).

Why? They are not part of the trailer tongue weight applied to the ball.

True. But they are both bearing down on the receiver.

[gijoecam]

RJCorazza wrote:
When weighing without the WDH, I believe you will need to add the bar weight to tongue weight ( if they were totally removed.).

Why? They are not part of the trailer tongue weight applied to the ball.

[RJCorazza]

When weighing without the WDH, I believe you will need to add the bar weight to tongue weight ( if they were totally removed.). With the tongue weight being comparitively small, and so critical, I also recommend the Sherman Scale. They are also available in a 0-2000 lb version for larger rigs.

[oxygen]

ChooChooMan74 wrote:

oxygen wrote:

ChooChooMan74 wrote:
Close. Tongue weight = Tow Vehicle weight with trailer minus Tow Vehicle Weight without trailer, NOT USING WEIGHT DISTRIBUTION HITCH>

This formula would give you the tt weight, not tw.

Trailer Weight would be Trailer and Tv combo (entire rig weight) minus tv alone.

I revised sobit would be clearer.

got it now, thanks

[ChooChooMan74]

oxygen wrote:

ChooChooMan74 wrote:
Close. Tongue weight = Tow Vehicle weight with trailer minus Tow Vehicle Weight without trailer, NOT USING WEIGHT DISTRIBUTION HITCH>

This formula would give you the tt weight, not tw.

Trailer Weight would be Trailer and Tv combo (entire rig weight) minus tv alone.

I revised sobit would be clearer.

[oxygen]

Just realized that the following may be the easiest formula to use.
tv weight with tt attached, (no bars) minus tv weight, no trailer

[oxygen]

ChooChooMan74 wrote:
Close. Tongue weight = Tow Vehicle weight with trailer minus Tow Vehicle Weight without trailer, NOT USING WEIGHT DISTRIBUTION HITCH>

This formula would give you the tt weight, not tw.