SRW vs DRW

[pressure_welder]

Good morning everyone hope your all doing well, So just recently we built a home off of a lake we used to camp at regularly, by doing that we've cut our camping in maybe half.... we spend our usual 1 month trip up at our favorite lake every year though, so our towing needs has decreased significantly, so i actually got rid of our 2015 ram 3500 limited drw about 2 years ago now just because i couldnt justify it carrying my butt around 90% of the year as a grocery getter. So for last two years ive been using the welding truck to pull our rig to the lake 2007 5.9 quad cab, with G56. The truck handles the load perfectly fine, its no rocket ship but it does quite well, on a side note the reverse gear on the G56 is HORRIBLE, your either riding the clutch the whole time or are a race car driver, geared way to high.

Anyway, the welding truck isnt horribly family friendly with the quad cab, and looking into weather or not a SRW 3500 would actually fill our needs accordingly, more comfortable for the family, easier daily driver, and a little more justifiable to own than a dually year round as my personal vehicle. Our situation is a bit different and i am not sure how to read it. We pull our camper and boat in tandem and here are the specs.


2018 montana 305RL - 14,270LBS loaded weight, 2395lbs pin weight

19FT crestliner sportfish - 3800LBS loaded weight/trailer, 300LBS tounge weight. on a tandem axle trailer, 23FT overall length


so with these numbers gets us in around that 18,000LBS total mark. However if i just had the fifth wheel a SRW 3500 should handle that without issue.... ive always thought of the boat as dead weight when in actuality its just rolling resistance of course until your stopping. Would i be correct to say that just adding the toungne weight of the boat to the camper weight, and maybe even 1000lbs extra for rolling resistance, would have me still safely within a SRW 3500 towing capacity?

all in all our main focus is to just acquire somthing more practical to own year round, and not have to use the welding truck to haul the rig up to the lake. Personal vehicle at the moment is a laramie eco diesel which is an amazing commuter, but i do miss my 6.7

[fj12ryder]

Flashman wrote:

Mike134 wrote:

fj12ryder wrote:
If you have more contact surface, you'll have more friction/braking. That's why race cars have very wide tires: bigger tires=better grip.

Yep!! I can tell you paid attention in your HS physics class.

Consider a train - very small contact surface and pulling more than any RV. It is psi on the contact patch - the larger the patch the less PSI if the weight is the same.

Now if that were true, race cars and dragsters would have very skinny tires. But they don't, why do you suppose that is?

[Flashman]

Mike134 wrote:

fj12ryder wrote:
If you have more contact surface, you'll have more friction/braking. That's why race cars have very wide tires: bigger tires=better grip.

Yep!! I can tell you paid attention in your HS physics class.

Consider a train - very small contact surface and pulling more than any RV. It is psi on the contact patch - the larger the patch the less PSI if the weight is the same.

[Cummins12V98]

"At 93,000$ for our 2015 I just about puked."

Are you in Canada??? CUZ My fully loaded Longhorn was 63k in 2015.

[Cummins12V98]

fj12ryder wrote:
If you have more contact surface, you'll have more friction/braking. That's why race cars have very wide tires: bigger tires=better grip.

The contact patch width of my skinny rear tires combined is not much wider than modern 3500 srw tires.

[Grit_dog]

Now that we’ve established that, the Reason for the Ops truck selection should not be braking power.
If he really has that light of pin weight , that is also not part of the equation.
If the setup tows nice and steady then a srw will do fine.
Of all things, the sheer length and the fact it’s doubles, the stability of a dually I have to believe would be welcome. Whether it’s necessary, is subjective.

[pressure_welder]

I cant say that I can compare SRW to DRW braking characteristics as ive only ever towed heavy with a dually or our semi for the business. I can say that my 2015 cummins pulled and stopped night and day compared to our 07 but that's to be expected. I can also attest that our cummins pulled and handled our rigs better than my 2015 gmc dually. Id use our Kenworth but that's REALLY not family friendly.

Essentially just keeping an eye out for a lower KM ram 3500 srw, mega cab would be nice but I also haven't towed with a short box I understand that has his own set of issues. With the cost of new trucks now-a-days I wont ever buy a brand new one off the lot again. At 93,000$ for our 2015 I just about puked. My father inlaw just dropped that SAME number last week on a 2021 GMC AT4 3/4 ton.... you cant be serious.

[Mike134]

fj12ryder wrote:
If you have more contact surface, you'll have more friction/braking. That's why race cars have very wide tires: bigger tires=better grip.

Yep!! I can tell you paid attention in your HS physics class.

[fj12ryder]

If you have more contact surface, you'll have more friction/braking. That's why race cars have very wide tires: bigger tires=better grip.

[wing_zealot]

All else being equal - Until the tires lose traction, braking is solely controlled by the area of the pad and the pressure applied by the caliper

[4x4ord]

^^^^ Even if the tire to road surface were the limiting factor in braking you’re not necessarily going to get better braking by adding more rubber. Consider sliding a box containing a new refrigerator across your floor .... do you really think it would be more difficult to slide the box if you lay it on its back vs having it stand vertically?

[Cummins12V98]

I drive a Dually and tow more with much more weight than most. I don’t see the DRW stopping better as the 3500 SRW has the same brakes.

Truck stops truck and trailer stops trailer.

[Cummins12V98]

Flashman wrote:

Cummins12V98 wrote:

pressure_welder wrote:

Cummins12V98 wrote:
"2018 montana 305RL - 14,270LBS loaded weight, 2395lbs pin weight

19FT crestliner sportfish - 3800LBS loaded weight/trailer, 300LBS tounge weight. on a tandem axle trailer, 23FT overall length

Don't believe the RV pin weight, is this a fact or a guess??? Boat trailer is light on the pin.

That said if you are at or under your RAWR let er rip!!!

Also truck stops truck, RV stops RV and Boat trailer stops Boat trailer. If it does not have brakes it sure should!

Hey there, those stats on the camper are pulled directly from the placard on the camper itself so i imagine they have to be close

NO they don't!!!

Don't think I have ever seen a published "loaded" pin weight.

20% generally is a minimum and many times 25% loaded pin.

I think that having a rzr loaded (behind the axle) into my tow hauler lightens my pin weight - should be the same for the hitch weight of a boat.

300# hitch weight from the boat will lighten the pin weight by less than 300#.

[parker_rowe]

PastorCharlie wrote:
Considering that all equipment to be equal if the rear brake line is blocked and only the 2 front tires are active:

Adding the back brakes to the active front brakes will increase stopping friction 100%

Adding dual rear wheels will increase stopping friction another 50%

All stopping with the brake pedal depends upon the friction of the tires on the road surface.

If you are not locking the rear wheels stopping a SRW setup (I assume that is rarely the case with 2500-3K on the pin?), then the "extra friction" from the two more tires are not going to make it stop any faster.

So if the physical brakes are the same, as they often are in SRW vs DRW 3500's...and you don't need more rubber to stop the tires from locking up, then where are you gaining braking power?

If anything the extra rotating weight of 2 more rims, class E tires, hub adapters, etc are making it harder to stop.

I think that is what Grit was getting at.

[PastorCharlie]

Considering that all equipment to be equal if the rear brake line is blocked and only the 2 front tires are active:

Adding the back brakes to the active front brakes will increase stopping friction 100%

Adding dual rear wheels will increase stopping friction another 50%

All stopping with the brake pedal depends upon the friction of the tires on the road surface.

[Mike134]

mkirsch wrote:
90% of the braking is done with the FRONT wheels. The front brakes are for all intents and purposes the same between SRW and DRW models.

I'm not at all convinced that braking should be your primary concern here. I'm not at all convinced that ANYTHING should be of concern here.

I wouldn't be worried stopping 18,000lbs with a 1 ton. I stop 12,000 with a 1/2 ton.