Super Singles SRW vs. Dually DRW

[Darkbloodmon]

I was watching the tutorial video on the leaking axle seal thread (Very good btw) because I have a leaking RR on my SRW 03. The tutorial had a dually, and upon seeing the hubs I thought doing a rear rotor replacement was asinine the way it was designed. I know there's many ongoing controversies about how much a SRW can handle vs a DRW. But the beans of it are traction, brakes, and suspension. All things that can be improved.


Duallies are still running semi metallic's just as the 2500s, Duallies have added rear traction from the tires, and the suspension is beefier for more weight. Swapping a 3500 leaf pack to a 2500 is not hard and or getting bags. Neither is getting better brakes. On the topic of traction what's to say 10 lug adapter hubs and super singles won't do the same if not better given brakes and suspension are identical? For reference I'm talking about a 19.5.

For the purpose of this discussion throw legality out the window. When someone says I wanna go fast no one is talking about speeding tickets. I wanna pull heavy should parallel.

 

[AH64ID]

The brakes are already the same.

Assuming 3500 SRW to 3500 DRW the suspension is nearly identical too, since both have the same upper overloads. The DRW does use a different main leaf pack, but it’s only rated 7% higher than the one on the SRW.

I used to run 19.5’s on my 05. No 10 lug adapter needed as there are several 19.5” offerings on the 8x6.5” bolt pattern.

My 05 was a 3500 SRW with ride-rite airbags and a standard size hellwig anti-sway bar.

I would run 7500-8000lbs on the rear axle most the time but occasionally I was heavier. It handled great. The OEM upper overloads were never needed or engaged statically, so a 2500 with air bags would handle the load the same. The lateral stability was never an issue, but hauling heavy at high axle ratings sure does eat narrow tires up quick. Traction varies by surface friction. A DRW is not better in many low traction situations.

With a 245/70R19.5 you get 9000lbs of axle capacity, vs the RAWR of the DRW at 9,350. Close enough.

It’s also not illegal in most states for private use. Federal CFR’s also allow for modification to the OEM GVWR/GCWR and axle weight ratings.

 

[Darkbloodmon]

The brakes are already the same.

Assuming 3500 SRW to 3500 DRW the suspension is nearly identical too, since both have the same upper overloads. The DRW does use a different main leaf pack, but it’s only rated 7% higher than the one on the SRW.

I used to run 19.5’s on my 05. No 10 lug adapter needed as there are several 19.5” offerings on the 8x6.5” bolt pattern.

My 05 was a 3500 SRW with ride-rite airbags and a standard size hellwig anti-sway bar.

I would run 7500-8000lbs on the rear axle most the time but occasionally I was heavier. It handled great. The OEM upper overloads were never needed or engaged statically, so a 2500 with air bags would handle the load the same. The lateral stability was never an issue, but hauling heavy at high axle ratings sure does eat narrow tires up quick. Traction varies by surface friction. A DRW is not better in many low traction situations.

With a 245/70R19.5 you get 9000lbs of axle capacity, vs the RAWR of the DRW at 9,350. Close enough.

It’s also not illegal in most states for private use. Federal CFR’s also allow for modification to the OEM GVWR/GCWR and axle weight ratings.

Totally forgot about the SRW 3500s when I was writing, good point to bring up for comparison.

My 05 was a 3500 SRW with ride-rite airbags and a standard size hellwig anti-sway bar.

Are you referring to their rear sway bar for these trucks? I was considering one to help with the body roll from my fuel tank.

Were you on 19.5s square? How was the fuel mileage and driving feel compared to stock tires?

How do you think a rear stagger setup would ride with identical diameters square?

Is there a reason why most duallies aren't using super singles besides cost?

 

[AH64ID]

What do you mean by 19.5’s square? At all 4 corners? If so, yes. I had 5 19.5’s to maintain a full size spare.

What is a rear stagger setup?

Ride was smooth and you felt the road more, but not rough on most roads. No real notice in change to fuel economy. 19.5’s can’t be run at low air pressure thou. The lowest Toyo said I could run was 70 psi. That’s for ensuring the bead stays seated.

It would take a rather large 19.5 to get to the 9,750 axle rating on a dually. That diameter tire is prohibitive for several reasons. Dually also do gain some stability by have 4 sidewalls instead of 2, but most of the sway is still suspension.

Yes I was running the rear anti-sway bar.

I also don’t think these tires are called super single in reference to larger super single tires.

 

[Darkbloodmon]

Yes that's what I meant by square.

What is a rear stagger setup?

Stagger is a different tire size relative to the rear or front axles. Rear stagger would be most similar to tire setups used in drag racing applications, wide in the rear narrow in the front. In this instance I would be looking at a wider rear tire set but keeping the tire height square on 4 sides. Front would be narrower rear would be wider.

Which tires are you referring to? I am referencing too the super single tires that class 8 trucks run. As I'm doing more looking it seems the super single size is made for the 22.5s.

 

[AH64ID]

Yes super single would be larger wheels than the 19.5's you mentioned.

Even if the truck is 2wd I would run the same tires on all 4 corners. Unless you do some wheels larger than 19.5's I don't think you will find similar height but different width tires.

245/70R19.5 is probably the most common size used on 19.5 SRW trucks. 265/70R19.5 is a little bigger and used sometimes. I have seen 285/70R19.5 a couple times, they are a 35x11 and HEAVY!

 

[SSage]

I still prefer dually tires for my heavy loads. You can put commercial sizes on a SRW or even 22.5 wide base tires on if you like, but they aren't going to magically work better than a dually in all conditions. Mostly just better on the interstate. The dually stability is great to have, great in the rain too. I need good traction off pavement, super stiff tires suck running empty. I run fairly cheap and aggressive open lug tires on my 4x4 dually. They don't last long, but I don't get stuck much either. I haven't been stuck in a while...

 

[Darkbloodmon]

Yes super single would be larger wheels than the 19.5's you mentioned.

Even if the truck is 2wd I would run the same tires on all 4 corners. Unless you do some wheels larger than 19.5's I don't think you will find similar height but different width tires.

245/70R19.5 is probably the most common size used on 19.5 SRW trucks. 265/70R19.5 is a little bigger and used sometimes. I have seen 285/70R19.5 a couple times, they are a 35x11 and HEAVY!

It'd have to be 22.5 square then with whatever tire height will clear but just a wider rear. How much do you figure they would weigh? I know my stock steelies with new tires are around 88lbs per for a 265/7017

 

[AH64ID]

My 245/70R19.5’s were 124/corner, with aluminum 19.5’s.

 

[Darkbloodmon]

I still prefer dually tires for my heavy loads. You can put commercial sizes on a SRW or even 22.5 wide base tires on if you like, but they aren't going to magically work better than a dually in all conditions. Mostly just better on the interstate. The dually stability is great to have, great in the rain too. I need good traction off pavement, super stiff tires suck running empty. I run fairly cheap and aggressive open lug tires on my 4x4 dually. They don't last long, but I don't get stuck much either. I haven't been stuck in a while...

Subjective-ness aside there is a reason why class 8's are running super singles. I'm interested to know what objectively a dually rear does better than a super single. I'm trying to see weather or not a traditional dually set up ( tires alone) is worth it when you could easily just put on a commercial super single and achieve the same if not better function. After seeing the rear wheel bearing replacement on a 11.5 dually I have to say it's not worth it the way the brake rotors are bolted to the axle's hub. A super single on a SRW seems like a win win on both maint. and versatility.

 

[Darkbloodmon]

My 245/70R19.5’s were 124/corner, with aluminum 19.5’s.

that's alot of weight... I could only imagine what a super single would weigh mounted to a 22.5

 

[NIsaacs]

Subjective-ness aside there is a reason why class 8's are running super singles. I'm interested to know what objectively a dually rear does better than a super single. I'm trying to see weather or not a traditional dually set up ( tires alone) is worth it when you could easily just put on a commercial super single and achieve the same if not better function. After seeing the rear wheel bearing replacement on a 11.5 dually I have to say it's not worth it the way the brake rotors are bolted to the axle's hub. A super single on a SRW seems like a win win on both maint. and versatility.

I am not sure what you are trying to achieve. Do you need more tire capacity than oem for hauling/towing heavy with your SRW? So your question is, super single or oem dually? I would think a good 19.5 would be plenty for a pickup truck SRW rear axle.

Big trucks run super singles to save weight, a super single would gain you weight. In small town USA, they are hard to come by and are super expensive. Is rear axle gear ratio something to consider? Do you have a 4x4 or 4x2?

What is with the heart burn on oem dually hub maintenance/repair? That is not a normal high maintenance area.

 

[Darkbloodmon]

I am not sure what you are trying to achieve. Do you need more tire capacity than oem for hauling/towing heavy with your SRW? So your question is, super single or oem dually? I would think a good 19.5 would be plenty for a pickup truck SRW rear axle.

Big trucks run super singles to save weight, a super single would gain you weight. In small town USA, they are hard to come by and are super expensive. Is rear axle gear ratio something to consider? Do you have a 4x4 or 4x2?

What is with the heart burn on oem dually hub maintenance/repair? That is not a normal high maintenance area.

I'm just want to know weather a SRW can perform the same role of a DRW with a super single rear tire set. You mentioned a 19.5 on a SRW being plenty. Would you be able to match or come close to dually capacities with 19.5s? Everything else excluded (brakes, suspension).

This is just a hypothetical food for thought discussion, I'm not changing my tire setup. For reference lets say a 3.73 final ratio and 4x4.

The heartburn on dually rear hubs is when replacing the rotors. Having to remove the whole hub assembly and axle is a bit of work on your own and a pricey brake job at the shop. I don't drive a dually or have any friends of family that tow with one, so if anyone has any input chime in.

Do you run through brakes or tires faster towing consistently on a dually?

 

[AH64ID]

I'm just want to know weather a SRW can perform the same role of a DRW with a super single rear tire set. You mentioned a 19.5 on a SRW being plenty. Would you be able to match or come close to dually capacities with 19.5s? Everything else excluded (brakes, suspension).

As I mentioned above the 245/70R19.5's I ran got me to a RAWR of 9,080lbs, only 300lbs short of the DRW RAWR. That was a load index of 133 (4540lbs). That same tire now has a load index of 136 which puts the pair at a possible weight of 9,880lbs. So yes it's very possible and nothing fancier than 19.5's is needed.

I personally would stick to the DRW RAWR and not exceed it, regardless of tire capacity. We don't know what made Dodge limit it to 9,350 lbs, but we do know that is wasn't tires so it's something else.

 

[NIsaacs]

The heartburn on dually rear hubs is when replacing the rotors. Having to remove the whole hub assembly and axle is a bit of work on your own and a pricey brake job at the shop. I don't drive a dually or have any friends of family that tow with one, so if anyone has any input chime in.

Do you run through brakes or tires faster towing consistently on a dually?

With an exhaust brake you don't need brakes no clue on SRW v/s Dually.

The rear hub is really not a big job. By the time you need rotors, the hub could use an oil change, flush the bearings and inspect, then change the seal. They are all due about the same time.

 

[BigPapa]

According to this Michelin chart, a SS drive tire on an aluminum wheel weighs 233 pounds and an 11R22.5 steer on an aluminum wheel weighs 160 pounds.

 

[Darkbloodmon]

With an exhaust brake you don't need brakes no clue on SRW v/s Dually.

The rear hub is really not a big job. By the time you need rotors, the hub could use an oil change, flush the bearings and inspect, then change the seal. They are all due about the same time.

I did say at the top of this tread legality aside; safety is still a priority. An exhaust brake isn't enough for emergency maneuvers.

How long do you get on a set of factory rotors?

 

[Darkbloodmon]

According to this Michelin chart, a SS drive tire on an aluminum wheel weighs 233 pounds and an 11R22.5 steer on an aluminum wheel weighs 160 pounds.

View attachment 128006

That's alot of rotational weight for a SRW (466lbs)… considering 176lbs on stock 265/70/17 steelies for the rear axle alone. 19.5s are looking to be the better option. Another inhibiting factor on these commercial tires being the speed rating.

I usually cruise at 65-70 on the highway with a 3.73, that's a bit too close for these L(75) M(81) N(87) ratings on the 19.5 tires. It's also a bit concerning how cheap you can get some commercial tires, I could only imagine what some cooperate fleets are running to save a dollar on operational costs and make more per mile.

 

[NIsaacs]

I could only imagine what some cooperate fleets are running to save a dollar on operational costs and make more per mile.

Yes, Fedex runs a lot of recaps on the front even. The rear are mostly bald.

I don't have any trucks new enough to have disk brakes on the rear. The front rotors on the '01 are original, 364k miles, the '91 I changed rotors at 280k, it has 334k now. That's what I was talking about with an exhaust brake, the brakes last forever.

I do understand that rear disks are prone to road spray/contamination from the front wheels so they have a tendency to wear faster than the front.

My rear drums and brakes are both original, I have changed seals once, each.

 

[bcbender]

That's what I was talking about with an exhaust brake, the brakes last forever.

Over 100k on my 04, never needed brake front or rear!... Put the PRXB on day 1.