Hitch weight vs payload

[WV_Camper]

I have anew 2020 Chevy 3500 SRW with the Duramax engine. The payload on the door is 3769 but the hitch weight for gooseneck (and 5th wheel?) is 3180. Does anyone know why this is so much lower than the payload number? We would like to have the Montana high country 383TH, the hitch weight is 3225. So, this is a miss by 45 lbs. how much lighter would you expect the pin weight to be with my 850 lb motorcycle in the back?

[4x4ord]

rhagfo wrote:

4x4ord wrote:

dedmiston wrote:

4x4ord wrote:
I carry my 800 lb bike on a 200 lb lift. So I have 1000 lbs carried 2 feet behind the rear bumper of my fiver. My pin is lightened by about 700 lbs. I end up replacing some of that weight by carrying 400 lbs of weight in the bedroom closet over the pin.

To calculate how much weight will come off your pin you need to know the distance from the pin to centre of trailer axles; the distance from centre of trailer axles to the centre of your motorcycle when it is parked in the garage. Formula is simply:


Weight of bike x distance behind axle/distance from axle centre to pin = reduction in pin weight. If the centre of your 850 lb bike is parked 70 inches behind the centre of your trailer axles and the distance from the centre of your trailer axles to the pin is 350 inches your bike would reduce your pin weight by 146 lbs.

I'm having traumatic flashbacks to my horrible 7th grade algebra class where we spent 75% of the year dealing with fulcrums. I don't know why my dreaded teacher was so hung up on fulcrums, but 90% of us tuned out and had to play catch-up the next year to get back on track.

Having said that, how do you know where the fulcrum is on a tandem or triple axle trailer? Or is the fulcrum six feet wide?

I would expect that the more axles that are involved the less precise the fulcrum point is. but, because equalizers are used with our two or three axle trailers the fulcrum tends to be at the centre of the axles .... so on a triple axle trailer, the centre of the centre axle would be the fulcrum. A tandem would have the fulcrum fall at the mid point of the two axles. So long as the trailer and ground is level the equalizers do a pretty good job of distributing the weight equally to all the axles.

There
Is no true fulcrum point on tandem axles, the math gets pretty complicated.

So long as the equalizers are able to distribute the weight equally to the two axles the math is not difficult. Taking a pivot point half way between the two axles will yield the proper result for calculating how a weight placed a certain distance from the pin (or distance behind the axles) is distributed between the axles and pin.

[rhagfo]

WV Camper wrote:
I have anew 2020 Chevy 3500 SRW with the Duramax engine. The payload on the door is 3769 but the hitch weight for gooseneck (and 5th wheel?) is 3180. Does anyone know why this is so much lower than the payload number? We would like to have the Montana high country 383TH, the hitch weight is 3225. So, this is a miss by 45 lbs. how much lighter would you expect the pin weight to be with my 850 lb motorcycle in the back?

Well that 3,769 payload is only accurate until the truck hits the dealers lot. Anything the dealer added to the truck will reduce that number. Then once you have possession of the truck any and all the stuff you add reduces that number also. Time to head to the scales and get you truck weighed with all family and stuff and hitch, ready to go camping to see what you have left, good luck.

[dedmiston]

That's what I figured. It's a space-time continuum thing. Probably to cerebral for the Toy Hauler forum, or at least that's what my 7th grade math teacher would have said.

[rhagfo]

4x4ord wrote:

dedmiston wrote:

4x4ord wrote:
I carry my 800 lb bike on a 200 lb lift. So I have 1000 lbs carried 2 feet behind the rear bumper of my fiver. My pin is lightened by about 700 lbs. I end up replacing some of that weight by carrying 400 lbs of weight in the bedroom closet over the pin.

To calculate how much weight will come off your pin you need to know the distance from the pin to centre of trailer axles; the distance from centre of trailer axles to the centre of your motorcycle when it is parked in the garage. Formula is simply:


Weight of bike x distance behind axle/distance from axle centre to pin = reduction in pin weight. If the centre of your 850 lb bike is parked 70 inches behind the centre of your trailer axles and the distance from the centre of your trailer axles to the pin is 350 inches your bike would reduce your pin weight by 146 lbs.

I'm having traumatic flashbacks to my horrible 7th grade algebra class where we spent 75% of the year dealing with fulcrums. I don't know why my dreaded teacher was so hung up on fulcrums, but 90% of us tuned out and had to play catch-up the next year to get back on track.

Having said that, how do you know where the fulcrum is on a tandem or triple axle trailer? Or is the fulcrum six feet wide?

I would expect that the more axles that are involved the less precise the fulcrum point is. but, because equalizers are used with our two or three axle trailers the fulcrum tends to be at the centre of the axles .... so on a triple axle trailer, the centre of the centre axle would be the fulcrum. A tandem would have the fulcrum fall at the mid point of the two axles. So long as the trailer and ground is level the equalizers do a pretty good job of distributing the weight equally to all the axles.

There
Is no true fulcrum point on tandem axles, the math gets pretty complicated.

[4x4ord]

dedmiston wrote:

4x4ord wrote:
I carry my 800 lb bike on a 200 lb lift. So I have 1000 lbs carried 2 feet behind the rear bumper of my fiver. My pin is lightened by about 700 lbs. I end up replacing some of that weight by carrying 400 lbs of weight in the bedroom closet over the pin.

To calculate how much weight will come off your pin you need to know the distance from the pin to centre of trailer axles; the distance from centre of trailer axles to the centre of your motorcycle when it is parked in the garage. Formula is simply:


Weight of bike x distance behind axle/distance from axle centre to pin = reduction in pin weight. If the centre of your 850 lb bike is parked 70 inches behind the centre of your trailer axles and the distance from the centre of your trailer axles to the pin is 350 inches your bike would reduce your pin weight by 146 lbs.

I'm having traumatic flashbacks to my horrible 7th grade algebra class where we spent 75% of the year dealing with fulcrums. I don't know why my dreaded teacher was so hung up on fulcrums, but 90% of us tuned out and had to play catch-up the next year to get back on track.

Having said that, how do you know where the fulcrum is on a tandem or triple axle trailer? Or is the fulcrum six feet wide?

I would expect that the more axles that are involved the less precise the fulcrum point is. but, because equalizers are used with our two or three axle trailers the fulcrum tends to be at the centre of the axles .... so on a triple axle trailer, the centre of the centre axle would be the fulcrum. A tandem would have the fulcrum fall at the mid point of the two axles. So long as the trailer and ground is level the equalizers do a pretty good job of distributing the weight equally to all the axles.

[dedmiston]

4x4ord wrote:
I carry my 800 lb bike on a 200 lb lift. So I have 1000 lbs carried 2 feet behind the rear bumper of my fiver. My pin is lightened by about 700 lbs. I end up replacing some of that weight by carrying 400 lbs of weight in the bedroom closet over the pin.

To calculate how much weight will come off your pin you need to know the distance from the pin to centre of trailer axles; the distance from centre of trailer axles to the centre of your motorcycle when it is parked in the garage. Formula is simply:


Weight of bike x distance behind axle/distance from axle centre to pin = reduction in pin weight. If the centre of your 850 lb bike is parked 70 inches behind the centre of your trailer axles and the distance from the centre of your trailer axles to the pin is 350 inches your bike would reduce your pin weight by 146 lbs.

I'm having traumatic flashbacks to my horrible 7th grade algebra class where we spent 75% of the year dealing with fulcrums. I don't know why my dreaded teacher was so hung up on fulcrums, but 90% of us tuned out and had to play catch-up the next year to get back on track.

Having said that, how do you know where the fulcrum is on a tandem or triple axle trailer? Or is the fulcrum six feet wide?

[4x4ord]

I carry my 800 lb bike on a 200 lb lift. So I have 1000 lbs carried 2 feet behind the rear bumper of my fiver. My pin is lightened by about 700 lbs. I end up replacing some of that weight by carrying 400 lbs of weight in the bedroom closet over the pin.

To calculate how much weight will come off your pin you need to know the distance from the pin to centre of trailer axles; the distance from centre of trailer axles to the centre of your motorcycle when it is parked in the garage. Formula is simply:


Weight of bike x distance behind axle/distance from axle centre to pin = reduction in pin weight. If the centre of your 850 lb bike is parked 70 inches behind the centre of your trailer axles and the distance from the centre of your trailer axles to the pin is 350 inches your bike would reduce your pin weight by 146 lbs.

[rblanch]

Looks like you have the same truck and trailer weight as I do. I have a 2020 GMC AT4 3500 srw cc long bed. When I ordered the truck the GM website said it would have a payload of over 4,000# pounds however when it came in the door sticker says max payload 3,645# and 5th wheel pin weight 3,165#. My trailer is an 2018 Raptor 355 GVW17,000#.I did add air bags and replaced the Rancho shocks with Bilstein shocks and I have to say it is a very pleasant tow experience. I put 25# of air with no toys in and 20# loaded with toys. With SRW you need to pay more attention to tire capacity. the tires that came on my truck are rated at 3,750 per tire at 7500 rear tire capacity I'm way below tire capacity and slightly over pin weight.

[rhagfo]

JIMNLIN wrote:

WV Camper wrote:
I have anew 2020 Chevy 3500 SRW with the Duramax engine. The payload on the door is 3769 but the hitch weight for gooseneck (and 5th wheel?) is 3180. Does anyone know why this is so much lower than the payload number? We would like to have the Montana high country 383TH, the hitch weight is 3225. So, this is a miss by 45 lbs. how much lighter would you expect the pin weight to be with my 850 lb motorcycle in the back?

Actually you have two questions...and you got actual answers to both. Your last question cannot be answered with the exact weight as way too many variables. I don't have your exact trailer but from loading dozens of flatbed trailers/enclosed trailers/stock trailers I would agree with the poster that answered your last question.

In reality we can only answer your second question with the data off the VIN sticker of your TV, and a scale ticket of the TV being weighed.

As mentioned in an earlier post the allowable hitch weight for the GN/5th wheel, might be the difference between the base rear axle weight and the rear axle weight rating.

Not knowing how heavy you travel, can't really give final answer your questions.

The DRY pin percentage is just over 23% if when loaded to full GVWR of 17,105# your pin would be 3,934#. Even if you got it down to 20% it would still be 3,421# exceeding the pin weight rating again.

The other thing most ignore is the fact that beloved Payload sticker is only accurate, as the truck leaves the factory. After it leaves the factory any dealer or owner added accessories reduce that payload.

Conversely, anything added to the 5er, will likely only increase the pin dry weight putting in a worse situation than you have dry. I am sure you don't travel without food or clothes.

Good luck with whatever decision you make.

[lincster]

azdryheat wrote:
When I had my truck weighed with and without the toy hauler, the front axle weight was the same telling me none of the trailer's weight is on the front axle.

Agreed.

I have CAT scaled my setup multiple ways.
Truck only.
Truck with empty toyhauler.
Truck with full toyhauler.

My front axle weights on my truck only changed by 15 lbs, no matter the configuration.

[JIMNLIN]

WV Camper wrote:
I have anew 2020 Chevy 3500 SRW with the Duramax engine. The payload on the door is 3769 but the hitch weight for gooseneck (and 5th wheel?) is 3180. Does anyone know why this is so much lower than the payload number? We would like to have the Montana high country 383TH, the hitch weight is 3225. So, this is a miss by 45 lbs. how much lighter would you expect the pin weight to be with my 850 lb motorcycle in the back?

Actually you have two questions...and you got actual answers to both. Your last question cannot be answered with the exact weight as way too many variables. I don't have your exact trailer but from loading dozens of flatbed trailers/enclosed trailers/stock trailers I would agree with the poster that answered your last question.

[WV_Camper]

arhayes wrote:
Would you believe, the pin weight of our 43', 19,400 GW TH is within 20 pounds whether our Goldwing in on board or not. It is right at 4200 lbs. I would not plan on a significant change.

An actual answer to my question- thanks!

[arhayes]

Would you believe, the pin weight of our 43', 19,400 GW TH is within 20 pounds whether our Goldwing in on board or not. It is right at 4200 lbs. I would not plan on a significant change.

[Old-Biscuit]

Truck payload is based on trucks GVWR minus the trucks UVW
Payload is for ALL added weight and spread over both F/R axles of truck

Pin weight of gooseneck/5vr is 'carried' by trucks rear axle

That 3225# 'hitch' weight you posted is DRY pin weight based on the DRY weight of that Montana TH
DRY (shipping weight) 13,880# with a DRY pin (hitch) 3225# = 23% pin ratio

17,000 GVWR TH using a 23% pin ratio = 3910# WET Pin

Your 2020 truck with 7250# RAWR could handle 3400# WET Pin
So you really should be looking at THs with a GVWR of 15,000 for that SRW Truck