235/85-16 OK on Triple Axle Raptor?

[kazuaki]

Hey all, just experienced the first blowout on the stock tires on my 2013 Raptor 381lev. Stock size is 235/80-16. Has anybody with a triple axle setup likes this moved up to 238/85-16 without any clearance issues? I'm concerned a out clearance e between the tires. It seems the 238/85 size would give me a larger selection of LT tires to choose from.

[sourdough]

I have not made that swap. From what I can see the 235/85 is about 1" larger in diameter (tirerack.com). Also when you move from the 80 series tires to the 85 you are moving into passenger and light truck tires - that's why there are so many tire choices. They aren't the same as a trailer tire. Use the search bar in this forum and I'm sure you can find any number of discussions about that issue.

[bobbecky]

Actually, the 235/85 R16 tire that should be looked at, at least for an upgrade from the E rated ST tires, would be something like the Goodyear G614, an all steel, G rated trailer tire. These are called an LT tire, but are not intended to be on anything but a trailer. We upgraded on our two axle rig to the G614's, and the size difference will largely be un-noticed. Just make sure your wheels are rated for 3750 lbs/110 psi, to be able to fully utilize the tire. Being a 2013, your wheels should be OK, but still check. They are pretty pricey, but well worth the cost compared to the damage a blown tire can cause and the down time dealing with replacing a tire and fixing damage.

[kazuaki]

We camp mostly in the desert and pull the trailer through some sand. On occasion we have to air down truck and trailer tires until we get to harder ground. Would the G rated tires be able to handle that treatment as much as any other tire?

[EricLynnAllison]

I blew 3 tires in two weeks on my Raptor. I went to a truck tire place and they showed me how much cupping the tires I had left had grown and placed them next to a 238/85-16. The truck tire was shorter than the original tires which had significantly cupped. I went with the LTs all around. Now have 7000 miles on them. Clearance appears fine.

[kazuaki]

Which tires did you go with?

[EricLynnAllison]

Firestone Transforce HT

[jtyphoid]

I was uncomfortable with moving to a larger tire, especially with the way the shackles allow the axles to move.

After reading quite a bit about some of the options, I went with Maxxis tires of the same size as the original. Maxxis appears to have a good reputation.

[kazuaki]

I looked at the inside of the wheel when I pulled the flat off and see it is labelled as 3750lbs and 110psi. Maybe I'll look into the higher rated tires.

[kazuaki]

I just took a rough measurement and was surprised to see that with stock tires I only have about 2.5-2.75" between the tires. It doesn't seem like 85 series tires would fit unless these stock 80 series tires are taller than they should be.

[JRTJH]

There are a couple of threads regarding upsizing tires and some owners have found that modifications to the undercarriage, ie: moving or cutting away a part of the outrigger assemblies, must be done to provide the needed clearance to install even "slightly larger" tires. If I were you, I'd do some very serious and cautious measurements before I spent money on tires that would likely not clear the metal understructure that is located in the wheel wells.

If you do a forum search for "outrigger" and "wheel well clearance" you should find many of those threads.

Good Luck

[kazuaki]

I've seen those threads and looked carefully. On my 381 there are no outriggers or brackets directly over the tires. There's lots of clearance to the chassis everywhere. My only concerns is tire to tire clearance.

[chuckster57]

If the tires your considering are 1" taller and you have measured 2 1/2" between tires now, your clearance will be 1/2", Not enough IMO.

[kazuaki]

Actually, if the diameter is 1" more, then the radius of each tires is 1/2" more. So the gap would theoretically be 1.5". Even so, that doesn't seem like much. I'm not sure how much(if at all) the gap fluctuates as the suspension cycles or as you turn.

[chuckster57]

Your right, math wasn't my strong suit.

[kazuaki]

So, is anybody running the Sailun S637 on a triple axle Raptor (or similar) fifth wheel?

[notanlines]

Kazuaki, we left Tire Kingdom in Fort Myers yesterday with four new 637's on our Raptor. Total price installed with new high pressure valve stems (no cost) was $700. It lowered the distance between tires by 3/4 of an inch. The tires run 110 PSI and the tech (?) 80 PSI so we settled on 100 PSI until I can look into it further. In the meantime I boosted it to 110 on the way back to the RV park.

[kazuaki]

UPDATE: I got the Sailun S637 tires installed on Friday morning and went on a short weekend trip (just 60 miles round trip). The tires fit the trailer fine. I certainly wouldn't want them any larger, but I think they'll be fine. One of the stock 235/80-16 tires I removed was over 32" in diameter. Yes, it was over an inch larger in diameter than the rest of the tires. I'm guessing some of the belts under the tread area had failed or something. The new tires are incredibly heavy. I now have some concern that the stock spare tire winch is adequate to hold that heavy tire up. I may install some sort of removable safety bar or something under the spare as insurance against a winch failure.

[chuckster57]

So 7 tires.. Like buying tires for my dually!!

[kazuaki]

One thing I noticed, the trailer seems to pull easier, maybe due to less rolling resistance. I'm not sure if its just my imagination or what :)

[kazuaki]

I know these S637's are rated at 110psi. Are their ratings for lower pressures? Just wondering if its OK to run at 100 psi or 90 psi. Its not worth it if it compromises safety of course.

[Quad]

Yes you can run them at a lower PSI. Just use a load inflation chart. I use to run mine at 100 psi. I removed the rubber valve stems and installed metal valve stems on my rims. Then I'd run them at my wheels max PSI of 100 psi. Since then I contacted Sendel wheels about my wheels. I asked some loaded questions they wouldn't straight forward answer (obviously), but after asking the questions, the person ask me to call them. When I called their direct number we talked about what I was wanting and what I was doing with my 5er and I was told with installing metal bolt in valve stems my wheels would be sufficient for running at 110 psi. That doesn't mean everyone's is just because I do it and it works for me. But I felt good with their expertise and knowledge and it only being 10 psi over my max published PSI. Been that way all last year over about 5000-7000 miles. Worked well for me.


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[Quad]

http://tapatalk.imageshack.com/v2/15/03/02/f0c47bd62377cd37c20155281b2d902e.jpg

Here is the load inflation chart the Manufacture sent me for the Sailun S637.


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[kazuaki]

Excellent, thanks

[kazuaki]

Another trip in the books. Just wanted to update anyone considering this upgrade. The tires roll well and the clearance is fine (on my fifth wheel anyway).

[CWtheMan]

A note:

Like the GY G614 the Sailun S637 is an all steel cased tire and like the G614 it is designed to be fitted to high pressure rims (110 psi) size 16X6.5. That's not a measuring rim size, it's the only size.

CW

[kazuaki]

CW, I have them mounted on 110psi wheels.

[randy69]

Hey all, just experienced the first blowout on the stock tires on my 2013 Raptor 381lev. Stock size is 235/80-16. Has anybody with a triple axle setup likes this moved up to 238/85-16 without any clearance issues? I'm concerned a out clearance e between the tires. It seems the 238/85 size would give me a larger selection of LT tires to choose from.

Went with 235/85-16 Michelin LT xp rib bought 7 American tire put them on my raptor. What a difference in tow.

[shmthaus]

So, how and where did you purchase your Sailun tires from?

[kazuaki]

I bought mine from the Big O Tires store right down the street from me.

[kazuaki]

Finally got the trailer back out to wash it, so I took a quick pic of the tires on it.

http://www.nuibe.com/trailer/raptor_tires1.jpg

http://www.nuibe.com/trailer/raptor_tires2.jpg

[Quad]

Looks good!


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[Pulln]

I had a tire separate this weekend as I was towing with my motorcycle in the garage. Given the predicament my wife and I consider the fact that this happened right before an exit that had a tire shop just off of it. The tire size issue popped up when speaking to the owner.

He said I should have 235/85's on my 09 Fuzion. When it comes to this I don't know if I am winding my butt or scratching my watch. So now I have some 16 month old 235/80's with one new 235/85.

I have no idea if where to head from here and would appreciate some good words of wisdom.

[CWtheMan]

I had a tire separate this weekend as I was towing with my motorcycle in the garage. Given the predicament my wife and I consider the fact that this happened right before an exit that had a tire shop just off of it. The tire size issue popped up when speaking to the owner.

He said I should have 235/85's on my 09 Fuzion. When it comes to this I don't know if I am winding my butt or scratching my watch. So now I have some 16 month old 235/80's with one new 235/85.

I have no idea if where to head from here and would appreciate some good words of wisdom.

A tread separation is a serious tire problem. It’s causes are numerous and normally from over loading, under inflation and speeding or any combination. A manufacturing defect causing tread separations will almost always cause the whole lot of tires to be recalled and sometimes the entire production of that tire in a particular time frame.

Using different sized tires on the same axle is also a serious problem.

There are a lot of factors to be considered when considering replacement tires. It’s not like changing tires on our motorized vehicles which have numerous approved options. Trailer axles have very few options and most of them are not approved by the trailer manufacturer.

Because most Original Equipment (OE) tires for RV trailers are barely adequate for the loads they are carrying, owners will want to go with replacements that are going to give them some more - needed - load capacity. It’s called plus sizing. To do that you need to know the load capacity of the OE tires at the vehicle manufacturers recommended inflation pressure (s). The maximum load capacity of the rims the OE tires are mounted on and the actual rim width if you're sticking with it’s diameter. Look-up the physical dimensions of the OE tire. Sometimes the trailer manufacturer has already put on the largest tire that will fit safely into the wheel well and still have enough clearance between opposing tires (1” min). Your replacements will have to fit into that wheel well with enough clearances.

The most desirable replacement will be of the same physical size as the OE tire but with a higher load capacity - by inflation. That’s because, with a little luck, the rim will be able to support the increase in load capacity (the rim load capacity will determine it‘s maximum psi rating).

There are no true LT235/85R16E tires with enough load capacity to replace the ST235/80R16E tires. The LT235/85R16G - a trailer tire - would be the best size replacement, but it will almost always require new rims because of it’s load capacity, psi rating and minimum rim width of 6 and ½”. The steel offshore tire also has that rim width. Other options are the ST235/85R16E rated at 3640# 80 psi, or the ST235/85R16F rated at 3960# at 95 psi.

To stay away from tread separations with the replacements don’t skimp in tire inflation pressures, air them to the sidewall pressures.

CW

[C130]

I had a tire separate this weekend as I was towing with my motorcycle in the garage. Given the predicament my wife and I consider the fact that this happened right before an exit that had a tire shop just off of it. The tire size issue popped up when speaking to the owner.

He said I should have 235/85's on my 09 Fuzion. When it comes to this I don't know if I am winding my butt or scratching my watch. So now I have some 16 month old 235/80's with one new 235/85.

I have no idea if where to head from here and would appreciate some good words of wisdom.

I replaced my 235/80/16 tires with Michelin XPS Ribs which are 235/85/16 over a year and a half ago. So far, I'm very happy with them and will test them out more in the next few weeks as I'll be traveling over 2,000 miles.

I'm trying to replace my spare tire now with the Michelin and found a guy with 6 of them in excellent shape. He said he'd sale one tire then when I told him I wanted it he never replied back. He's in Houston if anyone needs 6 tires and he said they have around 70% tread left, not sure of the age. $475 for 6 XPS Ribs so they are priced decent I think.

[Pulln]

A tread separation is a serious tire problem. It’s causes are numerous and normally from over loading, under inflation and speeding or any combination. A manufacturing defect causing tread separations will almost always cause the whole lot of tires to be recalled and sometimes the entire production of that tire in a particular time frame.

Using different sized tires on the same axle is also a serious problem.

There are a lot of factors to be considered when considering replacement tires. It’s not like changing tires on our motorized vehicles which have numerous approved options. Trailer axles have very few options and most of them are not approved by the trailer manufacturer.

Because most Original Equipment (OE) tires for RV trailers are barely adequate for the loads they are carrying, owners will want to go with replacements that are going to give them some more - needed - load capacity. It’s called plus sizing. To do that you need to know the load capacity of the OE tires at the vehicle manufacturers recommended inflation pressure (s). The maximum load capacity of the rims the OE tires are mounted on and the actual rim width if you're sticking with it’s diameter. Look-up the physical dimensions of the OE tire. Sometimes the trailer manufacturer has already put on the largest tire that will fit safely into the wheel well and still have enough clearance between opposing tires (1” min). Your replacements will have to fit into that wheel well with enough clearances.

The most desirable replacement will be of the same physical size as the OE tire but with a higher load capacity - by inflation. That’s because, with a little luck, the rim will be able to support the increase in load capacity (the rim load capacity will determine it‘s maximum psi rating).

There are no true LT235/85R16E tires with enough load capacity to replace the ST235/80R16E tires. The LT235/85R16G - a trailer tire - would be the best size replacement, but it will almost always require new rims because of it’s load capacity, psi rating and minimum rim width of 6 and ½”. The steel offshore tire also has that rim width. Other options are the ST235/85R16E rated at 3640# 80 psi, or the ST235/85R16F rated at 3960# at 95 psi.

To stay away from tread separations with the replacements don’t skimp in tire inflation pressures, air them to the sidewall pressures.

CW

Thanks for the info CW. I found one of your posts earlier today but hadn't had the time to follow up till.

I spoke to a locally owned tire shop and he helped explain many of the points you laid out above.

As a former sailor myself I am a staunch practitioner of PM checks before getting underway and have enlisted the help of my oldest child and wife as well. The only thing I didn't do is spot check my 16 yr old so there is a chance that pressure wasn't properly set. The tire did hold air through the loss of the tread which was a total surprise to me and the tire guys.

My son took a picture of the new tire yesterday and I am pretty sure that there is already a crack developing in it. Due to inclimate weather I haven't had a chance to go back out to the camper to confirm. The brand is Freestar and some quick research last night lead me to believe it isn't the most reliable out on the market to begin with so it will be coming off asap.

I am currently looking at Maxxis and hope to have them installed by a shop near my house tomorrow afternoon.