Largest tire size on your Axis/Vegas factory 16in rims

[sgrove]

Originally Posted by tjracer

...

sgrove if you have a inch between the rear sidewalls you should be ok . After driving for a while check the inside sidewall if they are shiny they are rubbing on turns. Remember the lower the air pressure the better chance they will rub. I think 55psi is to low could rub

Here are some pics of the spacing on our Vegas 24.1 with the Hankook DynaPro HT 225/75r16s.


The tires were essentially cold (76F here right now). No signs of shiny markings etc on inside of tires but we have run them at 75-80 psi. It is hard to see in the pics but the "bulges" near the ground/tire interface were slightly larger at 65 psi as you might expect. The spacing between the tire bulges was still about an inch at 65 psi. I slipped a measuring tape between the tires and you can see the clearance on each side of the tape. The tape is 7/8" wide.


I assume changing to the wider 235/85/r16 would reduce the tire spacing by about 0.4"?

[tjracer]

1 inch spacing is the norm. I thought you already had the 235/85r16 on the vegas. With the 235/85r16 tire on a factory 6 inch wide wheel it will suck the beads in causing the tire to bulge a little and the tire is widder.and the sidewall is taller so the bulge is bigger.the spacing will be about .5 sitting still. Remember a reg dw truck has opp. 3000-3500 pounds not loaded .you have opp. 8200-8500 pounds ( more bulging) camper is also 11 tall causing sway. So in my opinion the 235 tires will not hit sitting still but going around corners they will rub, thats why you need to look to see if the inside sidewall is shiney. Thats why the 55psi is low for a 235. Maybe you can go to a local tire shop and see if they have junk 235/85r16 have them mounted on your camper and see what the gap is.and then make your decision.
Its what ever you are comfortable with. For me .5 is not enough space

[ducksface]

Spacers are inexpensive and might do the job.
I'll demure to the tire guy and his knowledge of dually spacers.

At 55(I doubt they've been less)to 60 psi(more due to temperature) my 24.1 with stock hankooks don't rub.
We drive it like a normal vehicle. No unwarranted skeered, no babying.
If they would rub, we'd have rubbed them.

[tjracer]

Ducksface
i am talking about 238/85r16 rubbing . The 225/75r16 is stock size and will not rub. What size are you talking about.

[ducksface]

Originally Posted by tjracer

Ducksface
i am talking about 238/85r16 rubbing . The 225/75r16 is stock size and will not rub. What size are you talking about.

Whatever size a spacer might cure.

Mine are now 225/75. I was addressing low pressure and sidewall bulge about how mine do not rub.
The spacer question was for others here with fear of rubbing.

I'll put spacers in when I go wider if the at's are available for my 16's

I'm possibly too close for bigger tires in the front of my front flares without reworking the flare.
I dont have an inch+ of clearance, probably less on a squish.

[Big-Foot]

According to the tire engineer at BFGoodrich, one of the key concerns about dual tire spacing is cooling. Seems that uneven cooling of the inboard tire is an issue. Brake heat and lack of slipstream ….
Good thread!

[ducksface]

I think a pretty simple air scoop would fix that.
My left rear inside does run hottest by a few degrees, sometimes 10°
Maybe airflow blocked by the black tank.

[happy]

tjracer, using the 225/70R19.5 is the close clearance in the front wheels?

Our Axis came with steel wheels. Wrestling with this conversion and paying the extra for the aluminum wheels. The 19.5 steels sure seem heavy. We really like the extra strength these tires would give us. We have to drive several milers of gravel to get to the nearest pavement. The factory 16 inch seem so tiny for such a large vehicle. My F150 has heavier rated tires than our Axis.

[tjracer]

The front tires are close to the front flair’s.you could trim them if you needed to. They are not close enough to hit. Have put 11,000 miles on the upgrade with no problems that does includes going of road. I did the upgrade as soon as I purchased the coach. I did not like the 16 inch tires. I purchased the complete kit 4 aluminum wheels 2 steel wheels for dw caps and lug nuts with covers. I can get the part number if you need it.

[happy]

Thank you very much! I went to the website and found the kit you suggest. This seems like a good improvement for highway and especially rough roads.
That cost is making me really look at this and weigh all my options.


Appreciate you getting back to me.

[Big-Foot]

A link to these 19.5 wheels would be appreciated. We are debating replacing the whole coach or making updates and upgrades.
Thanks!

[happy]

https://buytruckwheels.com/

[happy]

tjracer an earlier post shows you went with Roadmaster RM170 and RM257 tires. How are they holding up? I had never heard of this brand so I'm very curious.



Do they have a good track record for say a 5 year run?

[Big-Foot]

Originally Posted by happy

https://buytruckwheels.com/

Thank you!

[tjracer]

Roadmaster is very popular in are area.they are a good tire for the money. Have had very very little problems with them. Been selling them for a long time. I wanted to try Toyo upfront but they where not available in a 12 ply at that time. I did get some in last week and put a pair on, but have not have time to run the interstate. Maybe next weekend. Trying to see tire handles better. The part # for the rims is. # 995604. At. Buy truck wheels.com

[happy]

Thank you for sharing your experience with the tires and the up-sizing.

[Jimbo56]

Yes, the spacing is important. Not only for cooling, but also to reduce the chance of a rock getting stuck between them. On 150 ton rock truck tires they actually have a steel bar between the duals (rock knocker).

Use of a spacer may also require different hub lug studs and lug nuts so that the OE are not stressed.

From looking at a chart, a 235/85r16 is about 2 inches taller than a 225/75r 16.
https://tiresize.com/chart/
This height difference will completely change your gear ratios and possibly over stress your transmission. It would definitely change your speedometer.

19.5’s should not even be a consideration.

IMHO

[tjracer]

The wheel kit is a direct replacement no spacers no stud change new lug nuts come with the kit. The studs only hold the wheels to the hub. These are hub centric wheels the hub holds the weight. The spacing is factory distance between tires for heat. I have been lifting trucks going from 30 inch tires to 42 lifted many e 350 vans to install 35 swapped 16 inch wheels to 19.5 on 1 tons some people even went to 20 s other than the speedo there is no mechanical problems. On the new stuff we reprogram the bcm to the new tire size. All vehicles manufacturers have been changing tire size if you order it that way. With the same drivetrain. There is no mechanical reason not to do the upgrade if that’s what a person wants to do. My next upgrade is a 4 inch lift on the front 2 inch lift in the rear using positive arch springs this will level the coach also adding a electric 5 inch step and changing inside step to get ride of the 10 inch first step to be 7. 3/4 I like to fabricate stuff.

[happy]

We got the 225/70R19.5 tires mounted with zero rubbing or tire contact anywhere except for the rear mud flap on one side and easily fixed. We had the tire shop install metal one piece valve stems so that no extenders are needed. There may be more airflow to the brakes due to larger wheel diameter, not sure that was ever an issue. I like having a shorter tire side wall on a tall vehicle.

The reserve capacity with these tires as well as the off road/rough rocky road ability compared to the factory tires is a plus for the area we live in and the places we plan to travel. The strength of the tires is huge!! The center line of the axles were lifted 1.3 inches. That may help clear a dirt clod or help my tummy not rub as much when I crawl under to check the chassis.

The factory wheels were all steel the new set up is 4 aluminum and two steel.

[Big-Foot]

Great info on this thread.
Those that have upgraded wheels & tires - please show off a little with some pics!!