Super single tire conversion dilemma yes/no?

[Victorian]

Hey everyone,

I’m currently debating the absolute need vs want factor about super single tire conversions for our C5500 GMC Top Kick expo truck.
we bought the truck last year with virtually brand new 11R22.5 tires. they have the correct load and speed rating, snow flake ( winter legal in BC) . To my knowledge there are currently no snow rated super single tires on the market that would work with this truck. Please correct me if I’m wrong. regular semi truck tires are fairly easy to source while travelling. MPT most likely not…..
with keeping the duals in the back I‘m hoping for redundancy in case of a flat or a tire blow out.

I'm Estimating that our travels will be 95% on highways and the rest on mild gravel / winter roads. therefore no extreme off roading where deep mud or sand should be expected.

Other, then the much nicer “overland look” why else should I consider going super singles?

what would you do?

couple of images for reference.

 

[Photomike]

You’ve touched on all the key points I consider.

Keeping the dual rear - The added safety, the ease of finding standard tires, the lower cost of common tires compared to specialized ones, and avoiding the expenses for additional modifications all make a strong case. Plus every time you do a mod it changes so many other things that never seem to work the same again.

Honestly, unless you're constantly driving in conditions where dual tires might get stuck or give issues, like deep hard tracks, mud or deep snow, I don’t think it’s a significant concern.

Some people argue that dual rear tires use more fuel, but when I compare the size and weight of singles versus duals, I don’t see much of a difference.

 

[Victorian]

You’ve touched on all the key points I consider.

Keeping the dual rear - The added safety, the ease of finding standard tires, the lower cost of common tires compared to specialized ones, and avoiding the expenses for additional modifications all make a strong case. Plus every time you do a mod it changes so many other things that never seem to work the same again.

Honestly, unless you're constantly driving in conditions where dual tires might get stuck or give issues, like deep hard tracks, mud or deep snow, I don’t think it’s a significant concern.

Some people argue that dual rear tires use more fuel, but when I compare the size and weight of singles versus duals, I don’t see much of a difference.

100% thanks

 

[Pacific Northwest yetti]

All solid points, and it’s always nice to see build(ers) thinking about what job their vehicle is for and adjusting accordingly. After all, our vehicles are just tools.

Singles allow you to air down, but if this is not needed. Duals can allow rocks to get stuck between them causing issues. But both are only factors if you are using them in areas where they are considerations.

All our brush, and interface fire engines are super singles. Mainly because guys seem to get rocks, and especially the igneous rocks we have in the PNW. They are pretty beefy but I am not sure if they are snowflake rated. Most have auto chains at this point.

 

[mog]

Large super singles in 22.5 are super easy to get in my area (Southern Oregon), with >20 in stock at my local Les Schwab tire store. And under 2 hours to get a used 80% tire to use as a spare (from another Les Schwab).

Both @Photomike and @Pacific Northwest yetti are spot on. So the only thing I can add, is your TopKick going to be 'just' a personal camping rig, or is it also going to be a rolling advertising / display truck at shows? If so then the very rare time that the 'Expo Look' is a real justification for super singles. Awesome cabin, super awesome subframe, and ya, OK, an awesome operator . . . go all in if it is an advertising/display element and go 22.5 super singles, if not, duals would certainly serve fine and save a whole bunch of CNDs.

That being said, 'good' 22.5 super single rims in 8x275mm are harder to find than a Tim Hortons in Florida.

 

[Photomike]

That being said, 'good' 22.5 super single rims in 8x275mm are harder to find than a Tim Hortons in Florida.

Love the Tim Hortons jab 😂
😂
My issue is always betting stuck someplace without tires or a doughnut 😂

 

[Victorian]

Large super singles in 22.5 are super easy to get in my area (Southern Oregon), with >20 in stock at my local Les Schwab tire store. And under 2 hours to get a used 80% tire to use as a spare (from another Les Schwab).

Both @Photomike and @Pacific Northwest yetti are spot on. So the only thing I can add, is your TopKick going to be 'just' a personal camping rig, or is it also going to be a rolling advertising / display truck at shows? If so then the very rare time that the 'Expo Look' is a real justification for super singles. Awesome cabin, super awesome subframe, and ya, OK, an awesome operator . . . go all in if it is an advertising/display element and go 22.5 super singles, if not, duals would certainly serve fine and save a whole bunch of CNDs.

That being said, 'good' 22.5 super single rims in 8x275mm are harder to find than a Tim Hortons in Florida.

good points! I never liked having my personal trucks/ campers as a display vehicle at expos. Sounds harsh but having strangers going through your “ home” opening/ touching everything never appealed to me. Therefore, it’s only for my family to enjoy. The expo look is certainly cool and ads to the curb appeal, but it also attracts attention on a daily basis while travelling. The current” commercial” look will hopefully help off set this a bit. I did not build this to attract marketing attention. A unimog would do a better job in that 😁 instead, I designed and build the interior in a way that will work for our use and with elements we learned from previous campers we owned.

I love my tim hortons snack stops on road trips 🥳

on a side note: in bc , from October to March, you need to have winter rated ( snowflake) tires on your car/ truck/ rv. They get really cranky if they catch you without! One of the biggest reasons i like to keep the current setup .

 

[Rubiconx1]

I started looking at super singles for my unit during the summer, so understand the quandary. However, my purpose was to increase my ground clearance and ability off-road, as we spend a lot of time dispersion camping instead of being a road warrior. My unit is built on an F550 4x4 chassis, and because of my intended purpose, this conversion is being done in January 2025. I’m adding a lot more upgrades/changes with my build, including front e-locker, gear changes, winch, lift, sway bars, shocks, etc, and adding an MPT spare to hedge against a failure and inability to find a replacement tire. As a result, the cost for my build is about $35k.

Given that your intended purpose is on road, coupled with the snow flake requirement, not sure the upgrade to super singles makes any sense…but it would sure round out the look of your rig.

 

[mog]

A unimog would do a better job in that

WOW you have to be a 'snowflake' 5 months out of the year 😇
Standard tires certainly would be the best choice in your case; snow rating, availability, cost (more $ for Tim Hortons), low key look, not having to find unobtanium wheels, and so forth.

I will say that a big plus of the Kodiak/TopKick (at least in my case), as once you have the wheels, direct bolt on with no suspension, gearing (5.13 stock, stock rear locker), modifications required. Around town and getting on the freeway I just run with the 'overdrive' off and it is 'normal', and then on the freeway hit the overdrive for perfect RPM cruising. My wheel offset makes me a little wider in front, but that also gives me full steering travel (53°).

Ahh, the old Bull vs. Bear debate. I vote for the bear


My Tim Hortons story.
We used to take our corporate jet to Vancouver once a year for maintenance. So my kids would go with me sometimes (9-10 years old). Years later when my son joined the Marines his MOS required a top secret clearance. When the DOS came to interview me for that, they ask about his trips to Canada, and "was there anything during those trips that could sway his allegiance to the United States". I replied "yes, Tim Hortons". Their response was "we do not joke during these interviews", Me "I wasn't".

 

[Rubiconx1]

…gearing (5.13 stock, stock rear locker), modifications required. …

Agree on needing to address the gearing. On my F550 chassis, I am changing to 6.17 gears as part of the build.

 

[Deleted Member 183]

Or you can go the route I did.

Wait for somebody building their "dream truck" that is so wealthy that "gravity does not apply to them" and they build their rig heavier than the weight class of the tires they bought! I got 5 brand new Continental MPT 81 365/85 for...

$600 delivered to my shop! 😆

 

[Blackdogvan]

On Stock 19.5's this Kodiak rode like a bag of hammers. What I figured was the best choice for me was Kelderman air in the rear and Deaver's HD +2" springs up front with Pirelli 335 MPTs all around. Finished it rides like a caddy. Smooth and so far from the stock performance I couldn't believe the difference. We drove it a bit between the suspension upgrades and installing the MPT's & I'd say the improvement was 50% suspension / 50% wheels and tires. The tires are new old stock Pirelli Pistas and although a few years old they have a amazing sealant applied at the factory so had no cracking and easily passed a commercial inspection.

The Kelderman install was interesting, it sorta fit, sorta needed massaging and Kelderman was sorta helpful with figuring it out. Deaver was a beauty to deal with, super helpful and a amazing product. I have no idea how they make magic leaf springs but they do. On the front axle we removed the spring spacer on the non pumpkin side and swapped the 1/2 height spacer (this will make sense if you see it) for the spring perches and otherwise it bolted up relatively quick and easy.

 

[gator70]

Super singles and that decisions was the sole reason I made ALL the choices I did.

Spending huge dollars on that set was a disaster for me.

In the end my super singles cost $485 each. But that required avoiding American trucks.

Most heavy trucks start with dual real wheels and the rear axle is narrow.

My bolt pattern is 222mm x 6

 

[cjken]

On Stock 19.5's this Kodiak rode like a bag of hammers. What I figured was the best choice for me was Kelderman air in the rear and Deaver's HD +2" springs up front with Pirelli 335 MPTs all around. Finished it rides like a caddy. Smooth and so far from the stock performance I couldn't believe the difference. We drove it a bit between the suspension upgrades and installing the MPT's & I'd say the improvement was 50% suspension / 50% wheels and tires. The tires are new old stock Pirelli Pistas and although a few years old they have a amazing sealant applied at the factory so had no cracking and easily passed a commercial inspection.

The Kelderman install was interesting, it sorta fit, sorta needed massaging and Kelderman was sorta helpful with figuring it out. Deaver was a beauty to deal with, super helpful and a amazing product. I have no idea how they make magic leaf springs but they do. On the front axle we removed the spring spacer on the non pumpkin side and swapped the 1/2 height spacer (this will make sense if you see it) for the spring perches and otherwise it bolted up relatively quick and easy.


View attachment 864778

Did you source the front springs straight from Deavers?
I’m interested in doing them on my truck.
If you remove the spacers does it keep the lift to a minimum? I’ve been hesitating to get the springs because I don’t want to lift the truck up any higher.

 

[Blackdogvan]

Did you source the front springs straight from Deavers?
I’m interested in doing them on my truck.
If you remove the spacers does it keep the lift to a minimum? I’ve been hesitating to get the springs because I don’t want to lift the truck up any higher.

I did get them direct from Deaver, HD Shocks sells their products as well & can pair them with a set of their rebranded King shocks specific to the Kodiak / Topkick chassis as well if you feel like shelling out some extra cash. Reports are they do wonderful things but I don't have 1st hand experience. I should say my improvements were also with fairly sacked out shocks so there are likely some comfort and performance gains left to be realized.

I ordered +2" but they have a design that is stock height & they make a ton of them for this chassis. (I have no affiliation with Deaver btw, just really happy and impressed with their product). The critical thing with Deaver is if your rig is built you can send your axle weights & they will tune the springs to your chassis.