Good evening, SF. As usual, I've got a curiosity question.

Lately I've been seeing 18-wheeler with, um, 14 wheels. The standard "four pairs" on the rear of the tractor are instead four big fat tires. I learned recently that's called a "super single," and I found a short article about them on http://truck-driver-blog.blogspot.com/.

The article is short and sweet, and addresses some of the questions I had about the advantages of the super single. What I don't see, however, is any mention of handling on slick or snowy roads.

As a car nut who once worked in a tire store, I know a little about vehicles and tires. I'll freely admit I'm neither expert nor guru. But having a little knowledge and a little experience, I end up with more questions. What's on my mind now is a slick or snowy road.

Typically, the really wide tire offers a large contact patch, which is great for traction on dry roads (think dragster). It's not so great, sometimes, for traction on wet surfaces in that it offers a greater opportunity for hydroplaning. In snow, a narrow tire can "slice through" the snow and get down to the pavement, instead of "floating" on the snow (think old-school VW Beetle).

So my question for the day is, does the super single bring a disadvantage on slick/snowy/muddy roads?

I’ve never driven one with singles, but those that have tell me they suck in bad weather. They’re also a pain to chain.

Some of the guys at work have them, but only the guys who do port work. The drivers who deliver to the various stores around the state do not. One guy did have them when he bought his truck, and immediately swapped them out.

I've seen these often. Never drove a rig with the fat tires. All those I operated were 18 to 22 wheels. Standard 18 is 80,000 pounds GVW. 12,000 on the steers, 34,000 at the drives and 34,000 tandems. There's your 80. Those fat tires must have equivilant load rating as a pair of tires. I've drivin 22 wheel rigs with a GVW of 107,000 pounds, 106,540 being the heaviest rig I've drivin.

Have noticed that the Super Singles are a lot scarcer here recently in Southern Michigan. It seemed like everyone was transitioning to them several years ago, now it looks like they have gone back to duals.

This message has been edited. Last edited by: NOCkid,

I drove about 250,000 miles in one truck with super singles, they are worthless in my opinion. They were mounted on aluminum rims for weight savings, they weren’t worth the hassle. They are terrible in bad weather, if you get off the round in any kind of greasy mud or grass you are done, with duels you may load them up with mud but they spit it out. They are terrible also if you are bob-tailing any distance, bounce is terrible. If you blow a rear you’re pretty much dead on the side of the road with them. With duels you can at least limp off somewhere if you have too. I’ve been in heavy equipment construction for a long long time and we never had one driver that had anything good to say about them.

Oaklane, your post addresses a number of the things I read last night. Thank you for that.

And wow, I hadn't even thought about the bob-tailing!

vthoky, thanks. I have been on the highway a number of times and wondered the same thing about the singles. Never remembered to post the question but now I have my answer.

SF comes through again with intelligent questions and answers.

I've heard they're like 8% more efficient........but too many drawbacks.

Oaklane has it spot on. My company went back to tandems.
We had tankers that didn't even have dollies,you couldn't
unhook. break down and you are screwed. I didn't drive the tankers
But if I would have broke down, I would have called my wife, come get me.
Call the company and tell them where the truck is at. Let them deal
with it.

If we were in Ottawa right now we could just walk downtown and see how many were using them.

Owner/driver perspective and snow use all in one.

I vaguely remember seeing some a while back - it stuck out - but rare around here. We have two interstates crossing E-W and N-S with a number of trucking companies and hubs, getting around locally in a four state region you see a lot of different rigs from all over the country.

Sounds like another flash in the pan that sold to corporate and later the field showed how they don't work. Oops.

I understood them to be part of the US EPA's "SmartWay" program that rolled out in late 00's.

I recall seeing on I-59 there were newly updated truck stops that had yellow tubes hanging down to go into the truckers windows so they could stop idling.
This had AC and other electronics provided through the tube.

HK Ag

vthoky,

I'm not sure of the reason for the super single, and this is a slight thread drift, but I thought your topic was interesting because at my work we make the wheels (rims) that the super single tires go on that you posted about. My plant is the only one in the US that makes wheels (for my company) and one of only 3 plants in the world that make the wheels (for my company.)

I've been there 4.5 years and still think the process of forging the wheels is very cool. If you had any interest I could get a few pics/short video.

quote:

Originally posted by remsig:
I've been there 4.5 years and still think the process of forging the wheels is very cool. If you had any interest I could get a few pics/short video.

Heck, yeah, I've got interest! I'm not only a car nerd, but I'm in manufacturing as well. I'd love to see that operation! Thank you.

quote:

Originally posted by vthoky:
Heck, yeah, I've got interest! I'm not only a car nerd, but I'm in manufacturing as well. I'd love to see that operation! Thank you.

Ok cool. I'll try and get a few pics and a short video tomorrow. I'll send you an email once I have them. Just be aware, our plants are loud and DIRTY lol.

One of the other interesting things I think is of the 2 buildings I work in one forges wheels on 3 presses start to finsh (5,000, 8,000 and 2,500 ton presses) and the other plant forges them on 3 presses and finishes them off on a spinner (5001, 5002 and 250 ton presses) then a spinner.

Each process is very unique and different but the wheels are the same when they are finished. I still can't figure out why the difference(I'm guessing the spun wheels are cheaper as they require less aluminum to start) aside from the fact that the older plant that only uses presses is much quicker (about 22 - 26 seconds from start to finish versus about 33 - 36 seconds for spun wheels.)

Those things would look great on the rear of a 32 Ford coupe!

I think the selling point was their being more efficient. I worked with commercial tires back in NJ and at the time they weren't really being used in my area. Large fleets were who the tire manufacturers wanted, I didn't have those as customers. Now living out West, I see them on a lot of trucks, again mostly large fleets.

I did meet a fellow that owned a large fleet and his operations folks transitioned to these. He told me his tire bills skyrocketed and was in the process of not ordering trucks with them. He was not long haul and these just didn't work for him. Typical of tire manufacturers to not really care about the end user.

Another style of Super Single is what you see on waste haulers, dump trucks, concrete trucks, they're a different size and used for their weight carrying capacity, usually 20 ply vs long haul that would be 14 ply.

quote:

Originally posted by remsig:

Ok cool. I'll try and get a few pics and a short video tomorrow. I'll send you an email once I have them. Just be aware, our plants are loud and DIRTY lol.

I’ll look forward to that. Thank you!

I’m familiar with loud and dirty… used to work (thankfully LONG ago) in a brake factory.

When we bought the ranch truck (‘92 International 4900 with DT466 engine, Allison auto trans, Fabco 20,000 pound front axle, Hendrickson 49,000 rear suspension) it came with six super singles on it. It had been a garbage truck on the beach on Sandy Eggo. We put a rolloff system on it (Well ACE in the valley did) and started building bodies for it. We build a rock body (looks a lot like a typical rock body, just has rails under it), a trash body (20’ seatrain container with the top cut out, a 10 gauge floor welded in it, and rolloff rails under it, and a 4000 gallon water truck body. The first time we put it to use hauling dirt, did not like the way the super singles squirmed around while dumping *AT ALL*. Quickly went to duals on the two rear axles and am *much* happier since.

It is really handy having a 6x6 on the ranch, but it is a little taller than the typical ten wheeler. Add on the rolloff frame and you really want the rear end as stable as possible. It is not as touchy as an end dump, but one still needs to be more careful than one would with a typical transfer truck.

They were all the rage. They save about seventy pounds per axle, so you could shed 280 pounds by changing out four axles. Add in around $5000 in yearly fuel savings, and fleets were going to them like crazy. I think now that “normal” size tires have improved wrt fuel economy, the savings no longer outweigh the benefits, so their use seems to be waning.

When you blow a tire, you often also wreck a rim. Those wheels cost quite a bit.