New Tires and Two Spares

[nickens]

We have 17,000 on the Rainiers under our 2022 295 and didn’t want to push our luck any further.

Getting ready for the 6,000 R/T to the Montana Owners Club National Rally in Goshen, Indiana, and a summer in Alaska in 2028, we bought 6 Sailun 637’s, the 235/80-16R are H rated so we have an extra margin of strength. (Only 0.9 taller)

We bought two spares because if we ever have blowout we change both tires on that side (we have history with trailer blowouts: the second tire blows in the next 60 miles…) Also, with two spares we will be doing a 6-wheel rotation so the spares get used and just don't rot away. The spare wheels match the original rims so everything will look peachy.

In order to mount two spares, I moved the existing mount forward of the axles and mounted new one behind where the original was. Moved the original forward as there is only room for a single-crossbar carrier forward of the axles with the plumbing hanging down: the new Lippert double rail mount would not fit up front.

A future project is to make carriers for two 14-17 gallon totes to be mounted one each side of the rear spare.

 

[Carl n Susan]

....we bought 6 Sailun 637’s, the 235/80-16R are H rated so we have an extra margin of strength. (Only 0.9 taller)....

AFAIK the Sailun 637 235/80/16R is a G rated tire. They are standard diameter. The 637 235/85 16R tires are also G rated with a little higher capacity and they are the ones that are 0.9" taller. The "80" aspect tires are what comes on the Montanas. They are fine for your needs.

 

[nickens]

AFAIK the Sailun 637 235/80/16R is a G rated tire. They are standard diameter. The 637 235/85 16R tires are also G rated with a little higher capacity and they are the ones that are 0.9" taller. The "80" aspect tires are what comes on the Montanas. They are fine for your needs.

I don't know how to post a pic, but it does say on the sidewall: L.R. H, 16 PR.

 

[LeftOverParts]

We had 2 spares each for the truck and trailer on our AK trip carrying them in the truck. Like your idea of locating one spare forward of the axles.

Recently saw a Sprinter model with the spare under the battery bay. I also had an idea of nesting the second one behind the current spare using tube stock with just bolts and no lift.

Seems a spare under the battery bay would distribute more wt to the pin so favoring a rearward position.

 

[nickens]

We had 2 spares each for the truck and trailer on our AK trip carrying them in the truck. Like your idea of locating one spare forward of the axles.

Recently saw a Sprinter model with the spare under the battery bay. I also had an idea of nesting the second one behind the current spare using tube stock with just bolts and no lift.

Seems a spare under the battery bay would distribute more wt to the pin so favoring a rearward position.

View attachment 1338103
View attachment 1338102

On potential issue with mounting further back is encroaching on that magical "angle of departure" line.

 

[Carl n Susan]

I don't know how to post a pic, but it does say on the sidewall: L.R. H, 16 PR.

Check out Post #8 in the Thread

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I don't know what you are looking at, but the S637 series are G rated and the only H rated Sailun is the S817 (which is a much bigger tire).

 

[LeftOverParts]

On potential issue with mounting further back is encroaching on that magical "angle of departure" line.

Thank you nickens. I did the “string test” (with a tape measure as a straight edge) from the bottom of the rear leveling jack to the bottom of the rear hitch and it looks like it would clear. That was with nesting the spares ODs about 2 inches apart. The custom tube would run even with the rear jacks. The one thing I didn’t consider was when the bike rack (+20”) or a future carrier is mounted. So this needs to be checked.

 

[rubio171]

Just a thought though…mounting the spare that far forward under the battery bay increases your pin weight.

 

[nickens]

We had 2 spares each for the truck and trailer on our AK trip carrying them in the truck. Like your idea of locating one spare forward of the axles.

Recently saw a Sprinter model with the spare under the battery bay. I also had an idea of nesting the second one behind the current spare using tube stock with just bolts and no lift.

Seems a spare under the battery bay would distribute more wt to the pin so favoring a rearward position.

View attachment 1338103
View attachment 1338102

I would have preferred that except 1- I couldn't find that same mount, 2 - using the lippert double-rail I could then add tote boxes on each side of the spare.

At the rally I saw someone who installed a mini-split from the main I-beam under the stairs. Now I'm rethinking that spare mount in front of the axles.

 

[nickens]

For those who thought I was crazy.
Well, a little crazy, but not when it comes to tires. This is a Sailun S637

 

[Carl n Susan]

Congratulations on finding a Sailun unicorn. Most tire sites only show the Load Range G flavor. But there is a Load Rang H version. The strange thing is that its Load Index is only ~100 lbs (4189) more than the LRG version. But the Max Speed is 81 M.P.H. (rather than 75 M.P.H.) for the autobahn drivers.

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