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Old 05-10-2019, 11:08 AM   #1
lundwc16
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235/80 vs 235/85

Getting ready for new rubber, & going to go with the Sailuns. I see by the Sailun chart that the 235/85 R16 has a 200lb higher load capacity than the 235/80, which is the stock size on my 2011 Montana. Anyone here go with the 85's over the 80's. Going to go with a pre mounted package from Trailer Set Go, anyone deal with them recently?

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Old 05-10-2019, 11:21 AM   #2
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Went with the 85's as I needed the albeit small increase in height.
What rims do you get with the pre mounts?
Why change?
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Old 05-10-2019, 12:04 PM   #3
lundwc16
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Originally Posted by prndl View Post
Went with the 85's as I needed the albeit small increase in height.
What rims do you get with the pre mounts?
Why change?
Last tire change was 5yrs ago, & I put 17.5" goodyears on the Monty, time for a change & I just don't like the Goodyears, although I never have had a problem, & have grown not to like having 17.5's on the rig. Trailer set go offers the 80"s for $285 & the 85's for $330 both mounted on aluminum rims rated for the correct PSI, & balanced with free shipping. Extras are center caps, & lug nuts.

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Old 05-10-2019, 03:08 PM   #4
Texan
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Why is the price difference so great? I have the 85's and the tires were not but maybe 10.00 difference at most.The wheels should be the same as 80 or 85's fit the same wheel even though the 85's are slightly taller and wider. I bought Hi-Spec modular wheels for my rv for 99.00 plus shipping not including center caps and lug-nuts. I'm not saying you are paying to much for the 80's but I do believe to much for the 85's. The 80's or 85's have more carrying capacity than the wheels at 3750#. For the price difference I would go with the 80's and I wouldn't go with a wheel that has a spoke as the spokes are the weak part of the wheel as I can attest to with having 2 go bad.
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Old 05-10-2019, 05:47 PM   #5
DQDick
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The replacement tires on our ould rig were 85's and worked well.
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Old 05-10-2019, 06:30 PM   #6
waynemoore
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I when from 80s to 85s why? Cause a bit better weight and I wanted to.
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Old 05-11-2019, 10:42 AM   #7
CalandLinda
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It's the axle spacing that can cause the most problem when going from 80 to 85. RV trailer manufacturers seem to put axles as close together as possible. Those with a 32" spacing will not allow the use of the 85 tires.

Another dilemma when changing from 80 - 85 is the tire placard and certification labels become invalid, as the tires are not of the same designated size and the load inflation charts for the 80 will not work for the 85.

Here is a ST tire load inflation chart.

https://fifthwheelst.com/documents/C...T-Modified.pdf
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Old 05-11-2019, 11:34 AM   #8
lundwc16
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Thanks for the info, are you referring to 32" between the axles?
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Old 05-11-2019, 12:35 PM   #9
CalandLinda
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Originally Posted by lundwc16 View Post
Thanks for the info, are you referring to 32" between the axles?
John
Yes, center to center. Most 85s are 31.7" in outside diameter and most axle manufacturers post clearances between tires should not be less than 1".

When measuring, I recommend doing both sides.
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Old 05-11-2019, 01:10 PM   #10
lundwc16
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I can't get under the rig to measure today, but I was able to find some interesting numbers on line. I currently have Good Year G114's on the trailer size 215/75 R17.5 Good Year says the outside diameter of the tire is 30.2". The diameter of the Sailuns 235/80 R16 is 30.9" & the 85 is 31.7" With the Good Years now I have about 3.5" between the tires, looks like I'll most likely stick with the 80's.
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Old 05-11-2019, 06:12 PM   #11
CalandLinda
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Quote:
Originally Posted by lundwc16 View Post
I can't get under the rig to measure today, but I was able to find some interesting numbers on line. I currently have Good Year G114's on the trailer size 215/75 R17.5 Good Year says the outside diameter of the tire is 30.2". The diameter of the Sailuns 235/80 R16 is 30.9" & the 85 is 31.7" With the Good Years now I have about 3.5" between the tires, looks like I'll most likely stick with the 80's.
John
What was the size of the OEM tires on your trailer? It'll be on the certification label. According to the specs I found the trailer could have been fitted with ST235/80R16 LRE or LRF. If so the switch back to a ST235/80R16 designated size would make the certification label valid again.
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Old 05-11-2019, 08:05 PM   #12
lundwc16
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Original size was 235/80R16
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Old 05-11-2019, 09:06 PM   #13
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At the worst you will be 1" closer than you were originally if you go to 85"'s. I used them for the increase in height (1/2")
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Old 05-15-2019, 08:49 AM   #14
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I just ordered sailun 85,s for my hc. Hope i have the room between looks like i have 5 inches or so. Should be good i need the extra height to level trailer
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Old 05-15-2019, 12:09 PM   #15
BuilderBob
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You should have plenty of room to use the 85's its only about 1" over all diameter then the 80's I put 85's on are 2017 and have about 4.5" and can still use my X-chocks just fine.
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Old 05-15-2019, 01:50 PM   #16
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After replacing Michelin due to age, went with the 235x85 Sailun tires, the same size as the Michelin tires I replaced after the lousy Marathon "Bombers". Only about 2500 miles on the Sailuns so far after going down to Arizona and back for the winter.
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Old 05-15-2019, 02:11 PM   #17
CalandLinda
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Originally Posted by bigred715 View Post
After replacing Michelin due to age, went with the 235x85 Sailun tires, the same size as the Michelin tires I replaced after the lousy Marathon "Bombers". Only about 2500 miles on the Sailuns so far after going down to Arizona and back for the winter.
So, you put tires with a maximum load capacity of 4400# each on 6000# GAWR axles.

Below is a link to a Sailun load inflation chart. To stick to tire industry standards, your Sailun tires should be inflated to a minimum cold inflation PSI of 80 PSI. You could actually go down to 75 PSI and still be within replacement tire standards. The 80 PSI will provide more than 20% in reserves per tire.

https://fifthwheelst.com/documents/C...T-Modified.pdf

Note: I may have misinterpreted the Sailun tire size as you did not use a proper nomenclature when explaining your tire sizes. Prefixes such as ST or LT are needed for proper size designations. I got the OE tire size from the trailer specs. I surmised your Michelins were LT tires, 16".

As you can see in the link below, Sailun does have the identical designated sized LT tires as the Michelins you replaced.

https://www.sailuntire.ca/PLT/AT.html
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Old 05-15-2019, 03:41 PM   #18
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No clearance issues with 85s on my 2016, 3711FL, and I can care less about "invalidating" the tire placard.
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Old 05-15-2019, 09:22 PM   #19
bigred715
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I had 235/85 16 Michelin at 80PSI when cold for my second set of tires after the 235/80 Marathon tires blew out. Replaced with Sailun 235/85 16 at about 90 PSI cold.
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