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Super Singles


Larry&Donna-AK

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For cool, when we were at a Freightliner Dealer in Iowa, we saw trucks with "Moon" wheel caps, the next step in streamlining. Works with duals.

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Mark & Dale
Joey - 2016 Bounder 33C Tige - 2006 40' Travel Supreme
Sparky III - 2021 Mustang Mach-e, off the the Road since 2019
Useful HDT Truck, Trailer, and Full-timing Info at
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Another full time trucker weighing in.

I agree all with all the negatives already presented.

There are 2 applications where super singles are indicated.

1. Weight savings in applications (tanker hauling repeat identical loads) where the aggregate weight savings translates into more gallons hauled per load over time to make a slight positive difference in fleet efficiency ($).

2. Fuel efficiency (2-3% avg)increase distributed over millions of miles traveled to justify the offset in increased costs and agravation.

 

You simply cannot justify the use of SS tires in the HDT RV arena on a cost or efficiency basis. If you think they are cool, do it, but you will pay for it.

 

 

(Disclaimer: I'm guessing here. Please flame gently when each of you wants to tell me I'm full of hooey.)

 

Dual tires offer a larger margin for overloading scenarios than super singles. Tankers offer an ideal controllable load where there's little to no risk of overloading (certainly no risk of gross overloading - the tank's not big enough, etc.). Other linehaul loads where the shipper identifies the expected weight of the load; if the carrier takes the load then checks it a few miles later on the scales, there's an easy opportunity to rectify the disparity before hours of highway speeds.

 

For single-axle HDTs with Smart-car beds and very aft hitch loads (potentially putting 1.2 pounds onto the drive axle for every 1 pound of pin weight), you've got to know your loads perfectly to know if you'll end up overweight, as you've got little option to fix it. Being overweight on super singles means more risk than if you left it as duals. Saving a couple hundred pounds in wheel/tire weight is probably not sufficient offset to make up for the tough loading conditions on a singled HDT.

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Dual tires offer a larger margin for overloading scenarios than super singles. Tankers offer an ideal controllable load where there's little to no risk of overloading (certainly no risk of gross overloading - the tank's not big enough, etc.). Other linehaul loads where the shipper identifies the expected weight of the load; if the carrier takes the load then checks it a few miles later on the scales, there's an easy opportunity to rectify the disparity before hours of highway speeds.

If you drove a shotgun (no baffles) tanker you would know that there is little control of a shifting load. Yet as the demonstration from Michelin used a tanker and shot a hole in a super single and the outer dual and the dual tire setup caused the driver control problems.

 

One of the issues of super singles on a single axle is that there is a much larger tire patch (tire contact with the road) which lowers the pounds per square inch and reduces some of the traction.

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Mark & Dale
Joey - 2016 Bounder 33C Tige - 2006 40' Travel Supreme
Sparky III - 2021 Mustang Mach-e, off the the Road since 2019
Useful HDT Truck, Trailer, and Full-timing Info at
www.dmbruss.com

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One of the issues of super singles on a single axle is that there is a much larger tire patch (tire contact with the road) which lowers the pounds per square inch and reduces some of the traction.

No. Show an independent scientific research document that backs this up, or please stop spreading this FUD.

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No. Show an independent scientific research document that backs this up, or please stop spreading this FUD.

Retracting this now for research

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Mark & Dale
Joey - 2016 Bounder 33C Tige - 2006 40' Travel Supreme
Sparky III - 2021 Mustang Mach-e, off the the Road since 2019
Useful HDT Truck, Trailer, and Full-timing Info at
www.dmbruss.com

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Here's some real science. For the same loading, tire OD and inflation pressures you would expect total contact areas to be similar.

 

Duals punch through surface slop better because it can migrate to the central void. SS provide better flotation for the same reason.

 

http://library.ctr.utexas.edu/digitized/TexasArchive/phase2/1190-1.pdf

 

Geo

George,
Suzuki Celerio 998cc

Yamaha NMAX scooter

 

Work ride is Western Star N2 Tri-Tri tanker at 56,500kg loaded

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Here's some real science. For the same loading, tire OD and inflation pressures you would expect total contact areas to be similar.

 

Duals punch through surface slop better because it can migrate to the central void. SS provide better flotation for the same reason.

 

http://library.ctr.utexas.edu/digitized/TexasArchive/phase2/1190-1.pdf

 

Geo

Bingo. Total contact area is similar for same load and pressure. Inflation adjustments relative to load affect the weight distribution across the contact patch; we've seen this for decades as tire/service advisors show us our tires' center vs. outer treadwear. And great assessment on the practical differences of how dual vs. single tires handle slush/mud (i.e. it's not the contact patch, it's the handling of liquid yuck immediately in front of the tire.).

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Remember these? ?

 

Same principal. Deep center groove to clear water/slush/mud.

 

Great in those conditions, but soft handling on dry roads and wear rates were worse than normal wide-base tires.

 

Great parallels to dual vs SS. Everything old will be new again.

 

 

I really like the look of SS. If money and the speed rating was not an issue, I would have a set of SS Michelin XZL 465s. Kill two birds with one rock. I don't see getting stuck on wet grass being much of an issue.

 

https://www.michelinb2b.com/wps/b2bcontent/PDF/XZL_WB_DataPg.pdf

 

Geo

George,
Suzuki Celerio 998cc

Yamaha NMAX scooter

 

Work ride is Western Star N2 Tri-Tri tanker at 56,500kg loaded

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Only 60 MPH???

XZL's are specialized tires for military vehicles. Note the load range. Also the weight per tire is crazy. I had them on my Pinzgauer in 255/100-16. 80#/tire

"There are No Experts, Do the Math!"

2014 Freightliner Cascadia DD16 600hp  1850ft-lb  18spd  3.31  260"wb
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The military stuff is on the other truck data sheet. 20 and 21" rims.

 

The data sheet I included is super singles in civilian sizes on 22.5 rims.

 

Airport crash tenders, any mixed application where you need a lot of off-road traction but still retain the ability to run on-highway for long periods at reasonable speeds.

 

Their predecessors, the XL, XML and XS had much lower highway speed ratings. A friend put XMLs on his 4x4 back in the 70s when everyone still used bias plys. Went anywhere you wanted to go and rode great. Noisy though with that tread. XZLs are quieter.

 

Geo

 

XZL's are specialized tires for military vehicles. Note the load range. Also the weight per tire is crazy. I had them on my Pinzgauer in 255/100-16. 80#/tire

George,
Suzuki Celerio 998cc

Yamaha NMAX scooter

 

Work ride is Western Star N2 Tri-Tri tanker at 56,500kg loaded

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