X2, I like the look of those tires

 

They are 255/80/17

When I got my F450 I wanted something more aggressive in the mud as I spend alot of time on the ranch. And I did not want to lift the truck. The tire choices for 17s is limited.

But the Coopers nailed it, these tires look and handle great. And are very quite for an aggressive tire. I have had Nittos and Goodyear off road tires and its crazy how quite these tires are.

Additionally you pick up about 1.20" height over a the OEM size. The speedometer is still spot on speed wise. And best part is the price $ 186 per tire.

 

Ok.. Seem to have the DEF issue dealt with..(knock on wood) Time to start the refurb ! I got a great deal on a set of tires, also a new bed. Bed also came with a tailgate with camera. Hope to use it.. Anyone here use a factory camera, with an aftermarket display???
anyway a few pics !

 

Paso450... do you ever load your dually heavy? What pressure do you maintain your Cooper tires at? How often do you check the inside dual?


Reason for asking is because the dual spacing in your photo looks a little tight. It could be just an optical illusion of the photo, but if those two tires started contacting each other off an on as they rolled from loaded to unloaded radius at over 600 times a minute, a lot of heat from friction could cause one of those tires to blow.







It's hard to say exactly how much clearance should be between dually tires, because the tire and wheel industry does not measure Minimum Dually Spacing by the gap. Instead, they measure from the centerline to centerline of each disc wheel in the dually pair, like this:





To make use of the manufacturer's minimum recommended dually spacing presumes that the tire mounted to the rim is the correct section size for the rim's width... not an oversize tire not specified for the rim width. In general, the manufacturer's suggest a 0.10 inch increase in dually spacing for every 0.25 inch increase in rim width.


For comparison, here is the gap between dual tires on stock steel wheels with stock sized tires:

 

Good points...
I also learned as a young mechanic doing truck fleet service that the gap also is part of the tire's "cooling" system and to maintain even cooling there needs to be a substantial gap.. What that gap is, however, was never made clear. Just that we had to use wheels that were mated properly and the right sized tires.

 

Paso,
Thanks. Those are exactly what I was looking at running.

I was also looking at a BFG TA KO2. 34x10.5-17. Yes they are Load range D, but only 100# less in load capacity. I need to research construction differences.

I really like the addition height of the Cooper.

Keith

 

I will have to double check what the distance was between the tires is, but it was virtually unchanged. The tire guys made sure of that . The picture of them is just at a bad angle.

 

I would certainly watch the distance very closely if you run some heavy payloads, the results could be catastrophic...

 

If questionable I would fully load truck to max on hard surface. Look at bottom of tires and be sure there is about 1/2 inch of space at bottom so there would be room for more flex at bottom fo bumps etc.

Just looked at tire rack web site. It says do not change tire size on duals for any reason.

 

when loaded down heavy you would be surprised at how much of a bulge there is against the pavement.


I had close to 5K in mine today and they top and bottom overloads engaged and they were still not touching with the stock width.

 

It isn't just loads or low tire pressures that can cause the loaded radius bulges to make contact.

It is running over pot holes. It is freeway exits. Mount a GoPro video camera under the chassis aimed toward the dually tires, and marvel at how much sidewall distension and lean the tires have when cornering through freeway exit cloverleafs.

Checking static clearance isn't enough. The dynamic clearances need to be checked also. Since I do not have the means to check dynamic clearances, I just stick with the manufacturer recommended tire to wheel fitments.

I wanted to upgrade to 245s on my dually, but my wheels were only 6" wide. If I upgraded to wider wheels from an F-53 Motorhome chassis, at 6.75" width, then those wheels would simultaneously widen the dual spacing. Therefore, not only would the shoulders of the individual tires be properly supported by the wider rim width, but the pair of tires and wheels together would be further spaced apart by the appropriate width to maintain adequate dually spacing.

I couldn't afford to change wheels, which meant I couldn't afford to buy one size bigger tire, even when both sizes were the same price... because I definitely can't afford to be found liable or negligent by ignoring all the fitment warnings found in the information from the tire manufacturers.

 

The radial design of the tire carcass allow a LOT of sidewall flex, hit a bump or any kind of road impact and you a result, add load you get a result. The distance (spacing) between the tires in OEM trim takes all that into account and you should never encounter any issue unless there is an extreme situation.

You are correct in saying a different set of dual wheels will give proper spacing...HOWEVER what has to be taken into account is there any resulting +/- offset in relationship to the axle attachment point and would this impact the life of the wheel bearing. This would be IMO a tricky area due to the potential loading of the truck in using it.

 

Paso,
Can you draw a tape on your rears unloaded overall and approximate center of hub (radius). Thanks

Keith

 

Will Do,

Yesterday I installed these step rails from Iron Cross. I did not like the King Ranch rails that much so I swapped them out. My goal was to find something that did not hang down too far and make the truck look lower that what it was.

 

1-3/16"

Just shy of a inch and a 1/4