SRW's for FUSO

whatcharterboat

Supporting Sponsor, Overland Certified OC0018
Actually Yves, IMO it is worse than that. With a SRW , the front wheels plough a set of tracks and the rear wheels follow happily in the same track. With DRW the front wheels plough a set of tracks and the 4 x rear wheels will each plough a track on either side of the front tracks. So instead of 2 tracks there are a messy 6, given that the front run a line close to the gap in the rear duals........................and as you say, the extra drag requires much more power and therefore increased fuel consumption, higher engine temps, etc.

Re: the DRW having more overall flotation. Very good point and true BUT.........with DRW in sand, the front OEM tyres have very little flotation so they knife in deep....then the rear axle which has an abundance of (IMO too much) flotation will not give enough drive so will spin and bog down. Its just a lose, lose situation.....especially the way many expedition trucks are setup with a more even front/rear loading.

.

GR8ADV, No thoughts on this? Kind regards John
 

pugslyyy

Expedition Vehicle Engineer Guy
GR8ADV, No thoughts on this? Kind regards John

Well, I disagree that "with DRW the rear wheels plough a track on either side of the front tracks" Would that it were so. The reality is that the rear axle will squirm from side to side trying to track down the path of the front axle.

I have to say that I have been very happy with the ATW wheel sets and would not consider running anything other than SRW on a Fuso. The only issue I had was that they weren't balanced correctly when I received them, but that was easily rectified.
 

GR8ADV

Explorer
GR8ADV, No thoughts on this? Kind regards John

Well I thought I had. It's quite interesting. The reason for me even gong down this path is that he big knarly singles are the way to go. So I just wanted to make sure they could air down well given the lack of bead. Apparently they can.

Specifically this knifeing argument is pretty weak given that the fronts if the 16's will float better than the 19.5's. As far as the back trackin g in the front I agree but they are very close together and really only if you are gong n a straight line on virgin sand. But it's a fun argument for someone selling them or someone going off to cover dunes. For the beach not so much. I don't think there r three tracks in this perfect as stated as they are Close together and not that far off the front track. Straddle I don't think so but I could be wrong here. Anybody got the facts here? I just don't thInk it is nearly as catestrophic as it has been made to sound. But I am open to getting smarter.

Maybe it is time for a myth buster. Haha. From the huge difference airing down makes ( we all know that) 70% on the 19.5's I can't imagine a situation where adding another 70% to that would not yield results beyond compare. But im open, it is just that the numbers are as significant as the propaganda. :)
The 19.5s have huge improvements in weAr and are the right choice for the road. The are amazingly durable and the right choice for rock and dirt. But to float in sand on the beach not so much. The numbers are just to much to overcome in my eyes. But make no mistake the 19.5s will work greAt in the sand as others have said. And those who have them know this but I have to think the 6 16s are far superior in this regard.

Again I am lookng for road manners, hands down to the stock, off pavement and Baja sand. We each have our own requirements. Inam on my phone so pls excuse my fat fingers.
 
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biggoolies

Adventurer
I am going to chime in on this as I have had some experience riding sand dunes in Saudi Arabia. (however not with duallies.) So I figured I was an expert in snow. Okay no problem in sand then. First trip out 4 North Americans stuck in sand. Arabs driving by with Toyota sedans past our stuck 4x4 without a hiccup.
You see what I am getting at is that no matter what equipment you have, if you don't now how to use it properly it won't help you in any circumstance. You will get stuck with your fancy SRWs if you don't know how to drive in sand while a dully flies by. I don't think those Saudis aired their tires down at all. I did watch what they were doing though and they would keep their revs up high. Keeping in a straight track is also a big mistake. Turning your wheels to the right and to the left when you seem to be bogging down gets you out of trouble. But the best thing I learned in sand is to look for the areas with vegetation as that is the firmest area to drive on. I have been with my truck in sand down near Palm Springs and I was quite surprised how it handled with all the negative talk about duallies. I was also pulling a military trailer behind me.
 

GR8ADV

Explorer
Agreed on severAl fronts. Wait. What. That can't be. The rear wheels have to be following right behind the fronts. No turning allowed. 🙀
 

whatcharterboat

Supporting Sponsor, Overland Certified OC0018
Again I am lookng for road manners, hands down to the stock, off pavement and Baja sand. We each have our own requirements. Inam on my phone so pls excuse my fat fingers.

Hahaha.......yeah. I have that problem too.

Not much more I can say. I thought this testimonial off the ATW website and written by a guy who had owned travelled in his his truck since 1998 and then had a SRW conversion done in 2013 was very relevant to this thread. Download the one from _JohnW

http://www.allterrainwarriors.com.au/testimonials
 
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westyss

Explorer
.
76% increase in resistance. I HIGHLY doubt that, but what do I know. Any idea where that number came from?? Are you referring to the added resistance of the rears riding outside of the track of the fronts? If so, that is real, but I really do not think it will be anywhere near 76%. BTW this benefit ONLY exists when if are driving in a perfectly straight line. :) Also if you are driving in any sort of track made by others it is further greatly reduced.
.
I am not trying to justify anything, I am just trying to look at it objectively without the green colored glasses of spending 5k that I have to justify. Or trying to meet a sales quota. :) Actually, I am trying to justify getting them, I want them to be awesome cus they look freaking cool and the dually's look lame IMHO.
.
Ok extra drag being out of the track, yup its there, that is why I couched the results with "limitations and efficiencies", however those inefficiencies will likely be considerably less than a 70+% gain in foot print and floatation that is gained and again only there when you are in a straight line. There WILL be additional rolling resistance of the duallys due to having more tires and thus more rubber on the ground, as well as additional resistance of the larger patch. But by definition, that is what we are trying to do with airing down, so we have to accept that knowing it is insignificant compared to the float aspect of the distributed load.

This does not take into account the benefits of wear of the 19.5 on the highway or the gearing. I am strictly looking for ride quality on the highway and off road traction in the sand.

YMMV






Im sorry, I thought you were having some fun with some numbers there...... the 76% was the number you came up with for the additional patch so I threw it out there, but anyway, I gotta say your numbers I realise were quick and I appreciate that but dont really tell the right story, perhaps a test would give better accuracy but my first thought when looking at your examples are that 35 psi is really not aired down enough but I am still guessing because there is no weight included in the equation.
The other part is the tire size, apples to oranges, seems like the 17"tire is bulging out to the point where the sidewall is making an increased contact patch, I could probably come up with a few more but either way we are not being very scientific about it by not including all the variables.

I do hear what you are saying about the cost and in the end it is your decision, if you are looking for first hand experience with 19.5 on an FG in Baja in the sand I can give you that and say they work great even in deep silty sand BUT the pressure has to be right, 5psi off and you are sunk.

I have only had one de-bead occur with my tires when I had a slow leak and most of the air escaped , there was no problem re-seating the bead, very easily done with on board air once the tire was off the ground, this all happened in the driveway.

The directional control with singles in ruts is much better than with duels.

Are you looking at either staying with stock or going to a 19" rim or are you deciding between stock, 17" and 19.5?

The terrain I have traveled on ie, sharp rocks, sticks etc and climbing some steep steps where the center of gravity increases the load on one or two tires makes me feel glad to have over rated tires.

Lastly for now is that having singles on the rear saved me 40% on the toll highways in Mexico! If I had duellies I would have paid like a commercial truck. I saved roughly $70! Which is alot of Tecate!

Along with Mogs good points about increasing the diameter and getting a better cruise speed and lower RPM makes it easy to spend your money from here.:ylsmoke:
 

westyss

Explorer
Actually Yves, it is worse than that. With a SRW , the front wheels plough a set of tracks and the rear wheels follow happily in the same track. With DRW the front wheels plough a set of tracks and the 4 x rear wheels will each plough a track on either side of the front tracks. So instead of 2 tracks there are a messy 6, given that the front run a line close to the gap in the rear duals........................and as you say, the extra drag requires much more power and therefore increased fuel consumption, higher engine temps, etc.

Re: the DRW having more overall flotation. Very good point and true BUT.........with DRW in sand, the front OEM tyres have very little flotation so they knife in deep....then the rear axle which has an abundance of (IMO too much) flotation will not give enough drive so will spin and bog down. Its just a lose, lose situation.....especially the way many expedition trucks are setup with a more even front/rear loading.

Yves, did you like the video?

Regards John.

I sure did john, too bad there is no sound on the Global vid as it looked like it climbed that hill effortlessly compared to the fire truck, but either way both did really well. Looks like the Global can take on more than that hill. I never got the opportunity to tackle sand hills so I am curious to hear if the Global could climb that hill by walking up it and not necassarily using momentum? Got any more?
 

GR8ADV

Explorer
Hahaha.......yeah. I have that problem too.

Not much more I can say. I thought this testimonial off the ATW website and written by a guy who had owned travelled in his his truck since 1998 and then had a SRW conversion done in 2013 was very relevant to this thread. Download the one from _JohnW

http://www.allterrainwarriors.com.au/testimonials

Make no mistake I am all over these being better. That way I can buy something that is way cool that I can justify as more functional. I am also very open to the idea that these work better(we already agree they work well) for reasons that are not obvious. Just trying to find it. Possibly it is that the longitudinal expansion when airing down is really far superior to width.

The customer post is interesting on three points. 1) he thinks that the rears running in the track of the front is great. ( does anybody know how the rears track on a stock setup as compared to the front? I don't know but I know it appears different than regular dually on an pick up that are really wide. Possibly this is where the notion came from. 2) that he benefits from a new larger tire patch, which is false as his new one is considerably smaller than what he had. 3) he thinks running 120 psi tires at 55 psi on the road is a good thing.

I'm pretty much done here myself unless someone has some new info. I am curious of the actual track on a fuso. If anyone knows the offset between the center of the front wheel and the center of the two rear wheels that would be great and would really add to the fact pattern. Better yet a pic of the tracks in the sand would be most excellent.
 

GR8ADV

Explorer
I sure did john, too bad there is no sound on the Global vid as it looked like it climbed that hill effortlessly compared to the fire truck, but either way both did really well. Looks like the Global can take on more than that hill. I never got the opportunity to tackle sand hills so I am curious to hear if the Global could climb that hill by walking up it and not necassarily using momentum? Got any more?

Yes the vids do show a lot of momentum carrying the trucks up and over. It actually looks like the truck comes to a stuck stop shortly after the momentum is lost. Not that it wouldn't with any tire setup.
 

GR8ADV

Explorer
Im sorry, I thought you were having some fun with some numbers there...... the 76% was the number you came up with for the additional patch so I threw it out there, but anyway, I gotta say your numbers I realise were quick and I appreciate that but dont really tell the right story, perhaps a test would give better accuracy but my first thought when looking at your examples are that 35 psi is really not aired down enough but I am still guessing because there is no weight included in the equation.
The other part is the tire size, apples to oranges, seems like the 17"tire is bulging out to the point where the sidewall is making an increased contact patch, I could probably come up with a few more but either way we are not being very scientific about it by not including all the variables.

I do hear what you are saying about the cost and in the end it is your decision, if you are looking for first hand experience with 19.5 on an FG in Baja in the sand I can give you that and say they work great even in deep silty sand BUT the pressure has to be right, 5psi off and you are sunk.

I have only had one de-bead occur with my tires when I had a slow leak and most of the air escaped , there was no problem re-seating the bead, very easily done with on board air once the tire was off the ground, this all happened in the driveway.

The directional control with singles in ruts is much better than with duels.

Are you looking at either staying with stock or going to a 19" rim or are you deciding between stock, 17" and 19.5?

The terrain I have traveled on ie, sharp rocks, sticks etc and climbing some steep steps where the center of gravity increases the load on one or two tires makes me feel glad to have over rated tires.

Lastly for now is that having singles on the rear saved me 40% on the toll highways in Mexico! If I had duellies I would have paid like a commercial truck. I saved roughly $70! Which is alot of Tecate!

Along with Mogs good points about increasing the diameter and getting a better cruise speed and lower RPM makes it easy to spend your money from here.:ylsmoke:

TOTALLY AGREE. MORE TACATE IS BETTER!! Yup a real tire for a heavy load. Agreed these are beasts and would instill confidence on any rock surface. Yup gearing is a big plus.

I am looking at stock or 19.5's. There are no mid sizes that don't lower the GVW. it is just my opinion but downsizing the GVW is just a bad idea. Even more silly as the alloy rims that down rate the GVW to save some weight when the weight of the 19.5 tires dwarfs that of the rim. But that is just my opinion and urs may be different.
 

gait

Explorer
76% sounds fine to me .....

but I'd tend to ask "76% of what?",

and rest assured "the ride quality will be 100% better",

could it be there's "data" and there's "marketing"?
 

mog

Kodiak Buckaroo
I was the same way before going to super singles, will the cost justify the results?
Obviously from my previous post, I think they are well worth it, with ALL of the benefits (not just 'off-road').
As far as off-road performance I believe that real world experience greatly outweighs all the ‘math’ in the world.
I do not believe that any of the Aussie operators that need to turn a profit could be hood-winked by a fast talking company into going the SRW route if it was not going to be beneficial to them. Mine operators surly put productively (profits) very high up on their list (I’d guess that only safety trumps that) and going SRW works for them. I’m sure every day some bean counter is checking that. Tour operators not only want profit but customer satisfaction (which equals profit). No driver is happy being stuck whether paid or not. Now add 20 unhappy passengers and as a company I’m sure you want the best possible wheel/tire set-up that is safe.
So in my ‘what should I go with’ process, I deferred to what my ‘brothers from downunder’ do.
Now straight cost wise, perhaps sticking with duels with be the most cost effective. Like most, my driving is at least 90% on road. So beside the cheap tire cost (even factoring in 6 vs. 4) the easy to meet load range, easier availability, probably better tire life and the added margin of safety provided by 4 wheels in back, duels would have been the answer. BUT I got all the other benefits of Super Singles and what I think is better off-road performance. I’ve been in the Oregon dunes (pretty ‘solid’ sand) with my truck and the added comfort of super singles gave me a lot of piece of mind. Could I have gone the same place with duels, maybe, would I have tried, no.
You can run all the numbers you want, but in my opinion there are too many variables to come up with a math solution. You can figure contact area, but what about HP, torque, gearing, WEIGHT, speed, etc, etc, that is one complicated formula.
I would think the best answer is to run a duel equipped and a SRW Fuso over the same terrain at the same weight, at the same time, and get real world answers. There are enough of us (FG owners) in the PNW that perhaps we need a FusoFest and try out the difference set-up with wheel/tires. I’d bet we could even talk ATW, EC, GXV, etc into showing up. Talked about a mass of information that would become available from that ‘experiment’.
I’d vote for Coos Bay for the sand dunes, and the hills east for rough roads.
Put me down for a 2002 FG running 37”x16 SRW at 11,500 lbs.
 

mog

Kodiak Buckaroo
A little off-topic, but it has come up in this tread as to ‘derated GVW'.
From day one I have planned to run my Fuso at a target of 20% less then it's GVW of 14,050 lbs.
So 11,250 lbs is my target. Will I keep it that low, probably not, but that is my goal.
The driving factoring was/is giving my truck an large margin of ‘error' in rough terrain, allowing for what would be overloading from my target, but staying under the rated GVW and generally adding life to my truck. Going to my choice of SRW makes the down rating a must do, but it still fits in my plans. So not a forced decrease for me.
Now an unintended benefit of running light is of course in effect more POWER. The Fuso is no F550 or Freightliner and (for me) on 6% grade hills or greater at max GVW it just dies. I have the dreaded curse of “O-s%#t not 3rd gear”. So in the range of max GVW of 13,500 AND greater, my poor Fuso just creeps up hill. But now at 12,000 lbs or less the same hills are pulled in 4th gear without a problem. Again an unexpected/unplanned benefits.
So just as SRW gave me many more benefits then just ‘off-road performance', derating my truck has had the benefit of in effect giving me more ‘power', which I surly needed.
(FYI –2002 FG, 2005 and later truck might not care with your 75 ft-lb of added torque)
 

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