Larger tire ???

crooks07 · 04-21-2016, 06:38 AM

I currently have Tow max 235 80 16 which are 30.8 inches in diameter on my 2016 Sanibel Traveler 38QB fifth wheel, axles are 33 inches on center leaving 2.2 inches between the tires. I want to upgrade to a 17.5 tire. I have been looking at the Sailun 235 75 17.5 which is 31.6 inches in diameter. This should leave 1.4 inches between the tires. I also looked at the 235 85 16 but they are even bigger at 31.7 inches in diameter. I know that the 215 75 17.5 is slightly smaller but I do not want to decrease in size if I do not have to. I am not looking for a tire debate on tires but to hear from anyone who has run their fifth wheel with a similar distance between their tires on a Dexter E-Z flex axle. I know Dexter states minimum clearance is 1 inch but I am look for responses from someone with real world experience. I dont want to spend the money and find out it will be a problem later on.

WTA · 04-21-2016, 07:00 AM

Trailer Tires & Wheels now lists both 235/80R16 and 235/85R16 Sailun S637's.

**ependydad** · 04-21-2016, 07:25 AM

Going to 17.5" rims, you can go with a lower profile tire that actually had a *smaller* diameter. I had less than 2" with my 235/80/R16 wheels/tires previously and ended up GAINING space between the tires when I upgraded.

I went with 215/75R17.5 in load range J. The tires specifically are Continental HTL Eco-Plus tires. 30.5" outer diameter.

I was actually able to buy the same brand/model/color rims in the bigger size. Nice because the look didn't change. I just went from 3,042 lbs. per tire of carrying capacity to 4,805 lbs.

I bought from Trailer Tires & Wheels and would happily buy from them again.

Skyliner · 04-21-2016, 07:43 AM

Im interested in buying your 16 in wheels if they are aluminum

**F.R.O.G.** · 04-21-2016, 07:43 AM

Crooks07, I've no idea what the clearance numbers are, but you might want to contact Rick Koelndorfer at Prime Time Service & Warranty to run the tire sizes that you're considering past him.

Besides the spacing between the tires, be sure that there are no issues with clearances above them as well. You can reach Rick at 574-862-3053, or by e-mail at RKoelndorfer@forestriverinc.com.

clr · 04-21-2016, 07:45 AM

I have a 2015 Sanibel 3601 and did the upgrade that you are talking about doing. I went with the 17.5 inch wheels and the Sailum 215 75R17.5 tires just to make sure that there was room. But after the install I would say that there is easily room for the Sailum 235 75 R17.5 tires. I have not measured the distance now between the wheels since it is slightly larger than before. If you would like me to measure let me know and I will take a short trip to storage and measure for you.
By the way I ordered a complete assembly from Tredit tire and wheel in Elkhart In the OEM provider for Prime Time. They were great to deal with and I was able to get a 17.5 inch aluminum wheel to handle the weight and pressure that looked similar to the wheels that came on the unit. The price was pretty good also may be worth a look. I did not have the tires and wheels shipped my son that works in South Bend picked them up COD from their counter. These things are heavy I would say over 100# a tire so shipping would have been over $200 est to my home.

crooks07 · 04-21-2016, 07:48 AM

I contacted Prime Time, they stated that the only answer that they could give me was stay with the same size tire. I will try Rick and see if he can expand on it. I also contacted Dexter and they said 1 inch minimum but I am looking for people that have that set up and their experiences with it.

clr · 04-21-2016, 07:49 AM

Bob
FYI, I did email Rick Koelndorfer at Prime Time Service & Warranty about my proposed tire and wheel change but after several weeks with no response I just when ahead on my own.

crooks07 · 04-21-2016, 07:55 AM

I have a steep driveway and a tall truck so I do not want to downsize the fiver tires unless I have to. My biggest concern is the clearance between the tires on the tandem axle.

**ependydad** · 04-21-2016, 08:49 AM

Couple of points above- the shipping for TT&W wasn't bad. $115 for me.

I got prices from Rickson, TT&W, and directly from Lionshead. TT&W was $400 cheaper than Rickson. And Lionshead didn't offer anything but Westlake in the size I wanted.

Total price for the 4 tires and wheels mounted and shipping - $2,255.00. The size is close enough to the 16" wheel that I kept that as my spare for now.

clr · 04-21-2016, 09:02 AM

Well when I run the numbers here as a double check for you. The GY 235 80R16 tire has a diameter of 30.7 inches, the Sailun 215 75R17.5 has a diameter of 30.4 inches and the 235 75R17.5 has a diameter of 31.6. So you have a distance between the tires now of 2.3 inches. If you go with the 235 75R17.5 tires you will have a distance between the tires of 1.4 inches just above the minimum of 1 inch. The GY 16 inch tire has a section width of 9.2 inches the Sailun 215 has a section width of 8.1 inches and the 235 has a section width of 8.9. So you are within the min for the axles but the final call here is up to you of course. In my case the local type tire guys were of little to no help most tried to blow smoke in order to sell what they had in stock.

By the way I paid 1,561.85 for the 5 wheels and tires mounted from the Tredit tires folks with no shipping included.

crooks07 · 04-21-2016, 09:24 AM

I think I am going to go with the 235 75 17.5 Sailun tires, the numbers seem to work. I am just looking for some real world experience before I spend the money. I appreciate all the feed back.

Airdale · 04-21-2016, 11:25 AM

Quote:

Originally Posted by crooks07

I think I am going to go with the 235 75 17.5 Sailun tires, the numbers seem to work. I am just looking for some real world experience before I spend the money. I appreciate all the feed back.

If you haven't done so you should touch base with your trailer's manufacturer. They will most likely give you a standard "canned answer" about the tires.

Your trailer is still under factory warranty. Ask them if radical tire changes in size and load range is going to cause any warranty coverage losses in the suspension and vehicle framing.

Helmsey · 04-21-2016, 01:57 PM

I had 235/80/16's with 2 inches between them and while I wasn't making the jump to 17.5's I initially was going to do the 235/85/ Sailun S637's and just have 1 inch between tires. Luckily I found the 235/80 Sailun's and went that route in the 16" tire and kept the same spacing. They have 4080 capacity and I couldn't justify the cost of wheels and tires in 17.5" to gain 800lbs of capacity per tire.

clr · 04-21-2016, 02:18 PM

Sure hope that you checked out the existing wheels to ensure that they were able to handle the increased weight rating and the higher air pressure required. In my case the existing wheels were only rated to 3580# and not rated for any air pressure above 80 PSI. This is why I changed the wheels also. So the wheel was acceptable only up to load range E and not above that.

crooks07 · 04-21-2016, 04:35 PM

I looked into just changing the tire but the rims are only rated for 80PSI, that is why I was looking at the 17.5 tires. I figure that if I have to change the rims to go to a higher pressure 16 inch tire why not go to the 17.5 for a few extra bucks. The 235 75 17.5 is actual smaller than the 235 85 16. I have 6 inches above the tire to the trailer for bump clearance so that should not be an issue. The numbers say that I am good and I have not heard anyone say that they have first hand knowledge otherwise. Just wanted to check before I spent the money.

clr · 04-21-2016, 06:53 PM

The sailun tire is 235 75 R17.5 has a diameter of 31.6 inch. The GY Marathon 235 80 R16 tire has a diameter of 30.7 inches. So the 235 75 R17.5 is larger than the 16 inch tire by only .9 inch not much at all but it is larger.

crooks07 · 04-22-2016, 07:54 AM

Yes it will leave me 1.4 inches between the tires, the axles are 33 inches on center.

Helmsey · 04-22-2016, 08:24 AM

Quote:

Originally Posted by crooks07

I looked into just changing the tire but the rims are only rated for 80PSI, that is why I was looking at the 17.5 tires. I figure that if I have to change the rims to go to a higher pressure 16 inch tire why not go to the 17.5 for a few extra bucks. The 235 75 17.5 is actual smaller than the 235 85 16. I have 6 inches above the tire to the trailer for bump clearance so that should not be an issue. The numbers say that I am good and I have not heard anyone say that they have first hand knowledge otherwise. Just wanted to check before I spent the money.

If I had to do rims in addition to new tires I likely would have gone the 17.5 route. I was lucky that my existing rims would accommodate the 110 PSI for the Sailun's

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