Super Single Tires

Are you spec'ing a single drive and tag on the glider?

 

Yup you need the lockers on the live axle, also here you have a weight transfer button so you can drive with more weight on the live axle and that improves traction, I think you can have it installed afterwards if you didn't spec it from new, also a rear lift tag has better traction in snow and ice than a double drive, all the Nordic hauliers use them here it's because the double drive has too much rubber on the road so none of the four wheels get enough grip.
Personally I've found a 1.2 mpg difference between a double drive and a tag axle but I've heard of bigger differences

 

I'd like to learn more about the single drive/tag axle setup but I'm worried about operating in the winter months. I'm sure they work better on a van setup because they seldom see an unpaved lot. My flatbed trucks on the other hand see them regularly. Throw some snow and ice into the mix and I'm really worried about getting stuck in lots.

 

with single drive and tag you can only stuck in mud


no problems


i would put double tires on drive axle ( because it is cheaper to run them) and single on tag and on trailer axles lightest best fuel economy and tire expenses


running super singles on tandem drive is absolutely stupid thing

there is few more ways how to get more economic truck than use super singles on drive axles , it is last thing i would do

 

Rear lift tags are brilliant in snow and ice cos you can put alot of weight on the drive and with only 1 set of wheels to be pushed harder through the ice, they are much better on snow and ice compared to a double drive but they aren't so good off road because on soft ground when the tag is down u don't get enough traction and if you lift it your live axle gets buried, a double is needed off road to spread the weight on soft ground but on a hard surface on ice a tag is king

 

I ran a Volvo 6x2 electo/hydraulic rear tag axle for years. The truck was unstopable no matter what conditions it faced....ice,snow,offroad etc. It never failed to go anywhere no matter what we threw at it.

 

No. Was going to, but getting things worked out proved to be a little problematic. I was already throwing them for a loop by spec'ing an 18 speed and 2.79 rear end ratio. Thought they were going to stroke out on me. If it had been a new production truck, then it would have been easier. I just went ahead and spec'd a Meritor RT 40-145 tandem axle set. Got the DualTrac option so that bearings are set so that whether you use duals or wide based, there will not be any reduction in bearing life. And they are 11mm aluminum housings. Nice weight reduction from steel.

You have to keep in mind, that Europe is light years ahead of us on this. It almost seems like some type of science fiction game to some of the dealers to spec a drive and a tag or pusher.

 

In my personal experience it's no where near 1.2mpg. And the drawbacks I've ran into with a tag out weigh the benefits. It's all in the application but I've got two daycab trucks, all spec'd to be light pulling grain hoppers (one T800 and one W900) and the W900 with the tag burns through tires, can get stuck on a pile of wet cat poo. Both have X1's, the truck with the tag used to have the weigh transfer valve (60/40) but that was removed and a full axle dump with valves to kill the brakes was installed because only transferring some of the weight wasn't enough to start an empty truck on wet pavement. Being able to leave the tag dumped helped tremendously. As far as fuel savings both trucks have 10 speeds and pull the same sized trailers 43'x96" with 80" sides and the T800 with the twin screw gets around 7-7.5 and the W900 gets just below 7. However the T800 has 3.70's and the W900 has 3.90's so I think the difference is due to the lower gearing and higher RPM.

So in my experience the fuel savings isn't measurable. I have a take off drive/tag axle setup that will bolt on any KW with the AG400 suspension I thought about putting under the T800 but I don't think it's worth it. If your doing a tag/pusher for the weight savings it may be worth it especially if there's any added fuel savings. However in the wrong application they're horrible. If you have a truck that's 100% on highway and runs in warm climates maybe, but here when it snows the dead axle truck sits.

Another thing to consider is when you go with a single drive axle that axle is larger and also heavier. So the weight savings are diminished slightly vs a twin screw. I'm not trying to talk anyone out of a dead axle, in some applications they work great. They're just not a "one size fits all" solution.

 

Narrower trac. Changes geometry. More dangerous. No thank you.

 

Our company has 2 double drive r620's and a tag axle r620, the average difference between them is 1.2 mpg, tyre wear should be the same as a double drive , there is no difference on the road unless you have an alignment problem and they won't get stuck on a wet pile of poo unless they are somehow set up wrong where the tag is carrying more weight than the drive